Masonry, Block Laying and Plastering Level 2

About this module

Level 1 taught you to build a wall. Level 2 teaches you to build a wall that stays up, looks right and earns money.

Who it is for. People who have finished Masonry, Block Laying and Plastering (Level 1), or who can show the same skills. National Proficiency II covers varied work, mostly routine, under limited supervision.

CTVET status. A national standard exists for entry-level block laying and tiling at National Proficiency I and II, written by the Ghana Skills Development Initiative with industry. CTVET lists Block Laying and Tiling at NP I-II and Building Construction at NC I-II. The standard documents themselves were not found, and plastering as a stand-alone CTVET programme was not found. This module is not a CTVET curriculum. It follows CTVET's format so it can be put forward later. Ask CTVET for the real standard.

Where the craft steps come from. No free Ghana hands-on manual was found. Many steps in this book come from UK, Australian, South African, Indian and Nigerian sources and are labelled foreign practice. Always check with your site engineer or supervisor. The text of the Ghana Building Code (GS 1207:2018) and a Ghana Standards Authority sandcrete-block standard were not found online: consult them at the Ghana Standards Authority.

Bridge from Level 1: what you already know

Site safety, PPE and the tools of the trade
Materials, and mixing mortar by hand with a gauge box or head pans
Setting out with lines and pegs; the 3-4-5 square; levelling
Laying blocks in stretcher bond: corners, courses, the DPC and simple lintels
Plastering a small wall, simple screeds and curing
Estimating a little, finding common faults and repairing them
Choosing where to work and how to market yourself

Level 1 did not cover reading a full drawing, setting out a whole building, concrete mixes and tests, block making, arches, reinforced and retaining walls, floor screeds in detail, crack diagnosis, a full quotation, scaffold awareness or supervising a helper. Level 2 covers all of these.

How the module works

Each unit has learning outcomes, performance criteria, the range and the evidence your assessor needs. You are judged Competent or Not Yet Competent. About 70% of the time is practical, following CTVET's Oil Palm programme split of about 30% school and 70% workplace.

Foreign practice and your engineer. Where this book gives a number such as a foundation width, a mix ratio or a thickness, it says where the number comes from. If your engineer's drawing says something different, the drawing wins.

Unit 1 · Reading drawings, measuring and setting out a small building

A wall that is a few centimetres out at the start is a hand's breadth out at the end. Get it right on the ground first.

Competency standard

Learning outcome	Performance criteria — the trainee…
1.1 Read a drawing	finds lengths, heights, openings and notes on a plan, elevation and section, and uses the scale
1.2 Set out a small building	marks the corners with profile boards and lines, squares them with the 3-4-5 method and checks the diagonals
1.3 Transfer levels	carries a level around a building with a water level or line level and marks it
1.4 Make and use a gauge rod	marks courses, openings and lintel heights on a rod and checks a wall against it

Range. A single-storey building of up to about two rooms on firm ground. Evidence. Marked-up drawing; a setting-out record; a level check; observation.

What the three drawings tell you

Plan: the building seen from above, as if the roof were off. It shows wall positions and thickness, doors, windows and room sizes.
Elevation: the outside of one wall seen from the front. It shows heights, window and door positions and the roof line.
Section: the building cut through, like a loaf of bread. It shows the foundation, the floor, the wall height, the DPC and the lintel levels.
Written dimensions beat a ruler. Never measure a plan with a ruler unless you know its scale. If a number is missing or two numbers disagree, ask the engineer or supervisor. Do not guess.

Scale

A scale of 1:50 means 1 unit on paper is 50 of the same unit on site. So 1 cm on the drawing is 50 cm on the ground. Method: measure the line in cm, multiply by the scale number, divide by 100 to get metres.

Drawing length	Scale	On site
18 cm	1:50	18 × 50 ÷ 100 = 9.0 m
12 cm	1:50	12 × 50 ÷ 100 = 6.0 m
4 cm	1:100	4 × 100 ÷ 100 = 4.0 m

(Example numbers; arithmetic checked by script.) Ghana blocks are commonly named 5, 6 or 9 inch by thickness; this naming was not verified from a Ghana standard, and the 6-inch (150 mm) block is the size most often tested in Sekondi-Takoradi.

Setting out a small building

The example is a building 9.0 m by 6.0 m outside. The method is the same for any size. This is foreign practice, adapted.

Tools and materials. 30 m tape; pegs (timber about 50 × 50 mm, 40 cm long); profile boards (timber about 25 × 150 mm on two pegs); builder's line; nails; plumb bob; club hammer; spirit level and a straight board; saw; water-level hose; builder's square; whitewash or lime powder. Buy timber, nails and line at a hardware shop or timber yard in Takoradi; ask for pegs cut from offcuts. Prices: ask three suppliers (Takoradi prices were not found).

Set out a 9 m × 6 m building

Find the building line. From the site plan, measure the setback from the road or boundary to the front wall. Check it with the supervisor. Drive peg A at one front corner.
Run the front line. Pull a line from A along the front. Measure 9.0 m and drive peg B. Pull the line tight and mark it on the ground with whitewash.
Square corner A with 3-4-5. Measure 3.0 m from A along the front line and mark X. Measure 4.0 m from A along the side line and mark Y. Move the side line until the distance X to Y is 5.0 m. The corner is then square. For long walls use multiples such as 6-8-10. Drive peg D on the side line at 6.0 m from A.
Find the fourth corner. Repeat the square at B. Measure 6.0 m along the side line from B and drive peg C.
Check the diagonals. Measure AC and BD. For 9.0 by 6.0 each must equal √(9² + 6²) = 10.82 m (checked by script). If they differ, move C and D a little and remeasure until the two readings agree within about 5 mm (a teaching target, not verified from a standard). Equal diagonals mean square.
Build profile boards. Drive stakes about 1.5 m outside each corner, outside the digging area. Nail a horizontal board to each pair, all at the same height, set with a water level.
Transfer the corners. Hang a plumb bob over each corner peg. Stretch lines between the boards so they cross exactly over each corner point. Cut a saw kerf (a small groove) at each line position so you can remove the lines for digging and put them back in the same place.
Mark the trench. Use the lines as the outside edge or the centre of the wall, as the drawing says. Mark the trench width on the ground with whitewash. Do not dig until the supervisor has checked your setting out.
Recheck. Before digging and again before the footing concrete: all four sides, both diagonals and the board heights.

Common mistakes and fixes. A bent tape or worn hook end: use a new tape and check it against a second. Profile boards at different heights: re-level them. A plumb bob swinging or leaning on a peg: steady it and wait. Marking the outside face when the drawing gave the centre line: read the drawing again. If the diagonals will not agree, check the sides first.

Transfer levels

A line level on a taut line works for short runs.
A water level is a clear hose filled with water, with no air bubbles. Water finds its own level, so both ends show the same height. This is common practice and was not verified from a cited source here. Use it for long distances and around corners, and check it against a spirit level on a straight board.
Datum: choose one fixed mark (a peg, or a mark on a wall) as your reference. Write its height on the drawing. Measure every other level from it.

Carry a level around a building

Fill a clear hose (about 15 m) with clean water. Remove all air bubbles by tapping and raising both ends.
Hold one end at the datum and mark the water height on the hose end.
Take the other end to the next corner. Raise or lower it until the water stands at the same mark, and mark the peg or board.
Repeat at every corner.
Return to the datum. The water should stand at the same mark, within a few millimetres. If not, repeat the legs to find the error.

The gauge rod

A gauge rod is a straight timber marked with the height of each course and the key heights on the wall. It saves measuring again and again.

Course height for a 225 mm block with a 10 mm bed joint is 235 mm (arithmetic from block size; Source: Structville Sandcrete). Keep bed joints at about 10 mm.
11 courses = 2.585 m; 12 courses = 2.82 m (checked by script). A wall 2.7 m high does not fit a whole number of courses. Tell the supervisor and adjust, for example by changing the floor level, or use a thicker bed joint only if the supervisor agrees. Do not squash joints to fit.
Mark on the rod: the top of the DPC course, the sill height, the underside of the lintel, the top of the lintel and the top of the wall.

Make and use a gauge rod

Plane a straight timber about 2.5 m long and 40 × 40 mm.
Mark every 235 mm from one end with a pencil and try square. Number the courses.
Mark the sill and lintel levels from the drawing in another colour.
Hold the rod beside each corner lead. The top of each block should sit on a mark.
Check every lead, and the wall every third course.

Foundations: what you set out

You do not design foundations. You set them out and build them to the drawing. For understanding only, foreign (Nigerian) training texts give an unreinforced strip footing 675 × 225 mm under a 225 mm hollow-block wall and 450 × 150 mm under a 150 mm wall, with the base about 900 mm below ground. These are not Ghana rules. Soil, slope, water and the number of storeys change the answer. Lack of a soil investigation, poor design and weak supervision are named causes of building collapse in Ghana. Follow the engineer's drawing.

What nobody tells you on a small site. Many small jobs have no drawing, only a sketch or a promise. Ask the client for a drawing, or draw one yourself with measurements, and have both of you sign it before you set out. It protects you if the client later says "that is not what I asked for".

Scale and setting out

A wall measures 15 cm on a 1:50 plan. How long is it on site?
A building is 12 m by 5 m. What must both diagonals measure?
You build 12 courses of 225 mm blocks with 10 mm joints. What is the wall height?
The diagonals of a 9 m × 6 m setting-out read 10.86 m and 10.78 m. What do you do?

Read a real drawing

Ask a mason, an engineer or the Assembly for a plan of a small house. Mark on it the wall lengths, the openings and the scale. Write three things you could not understand and bring them to class.

Check yourself: Unit 1

What does the scale 1:50 mean?
What must the two diagonals of a rectangle do if the corners are square?
Why do you use a gauge rod?

Unit 2 · Concrete and reinforcement basics, block making and formwork awareness

Concrete is only as good as the sand, the water and the care. Most failures are not in the cement.

Competency standard

Learning outcome	Performance criteria — the trainee…
2.1 Test sand and materials	does a silt test, checks cement and chooses clean water
2.2 Batch and mix concrete	measures a mix by gauge box, mixes by hand and uses it within 2 hours
2.3 Make and cure sandcrete blocks	makes blocks with a mould, cures them and checks them
2.4 Understand reinforcement and formwork	names bars, spacers and cover, and checks formwork for line, level and strength

Range. Hand-mixed concrete for small footings, lintels and slabs under an engineer's drawing; hand-made blocks. Evidence. Silt-test record; batching record; blocks made and cured; formwork check.

Cement, sand, stones and water

Cement. The Ghana Standards Authority (GSA) guidelines of January 2025 recommend Portland Limestone Cement or Portland Composite Cement 32.5R for plastering, masonry and screeding, and 42.5R for concrete products such as blocks and slabs. Older guidance names class 32.5 for plastering, screeding and block laying and class 42.5 for structural work such as columns and beams. Read the full bag marking. A study of five Ghana brands found they did not show the same strength build-up and some missed the 28-day threshold, so buy from a known dealer, in sealed 50 kg bags, and do not use a hard or lumpy bag. Another study found Ghana cement quality comparable to UK cement.
Sand. Clean, well-graded, with no organic matter. Do a silt test before every new load (see practical). Sea or beach sand carries salt that weakens concrete and corrodes steel: do not use unwashed beach sand. This warning is general advice and was not verified from a cited source; it matters at coastal sites such as Akwidaa. A Takoradi study recommended silt testing sand before block production.
Chippings (coarse aggregate). Clean, hard stones. For hand-made blocks the largest stone is 10 mm.
Water. Clean, drinkable. A water-cement ratio of about 0.5 gives peak block strength: add only enough water to be workable. On Kumasi sites water was judged by eye and not measured.

Concrete mixes (foreign figures; follow the engineer)

Use	Mix (cement : sand : stone)	Water-cement ratio
Reinforced concrete (lintels, beams, slabs)	1 : 2 : 4	about 0.5
Mass concrete (unreinforced footing)	1 : 3 : 6	about 0.6
Blinding (thin clean base)	1 : 4 : 8	not stated

(Nigerian training source; Source: WAEC Concrete.) The Ghana minimum for building concrete is 25 MPa at 28 days; on 11 Kumasi multi-storey sites, site-made concrete reached only 10 to 18 MPa because water, curing and testing were poorly controlled. A 1:2:4 or 1:3:6 volume mix hand-mixed on site will not guarantee the strength an engineer designs for. For a load-bearing element ask the engineer which mix and whether a test is needed.

Batching with a gauge box

A gauge box is a bottomless wooden box of known volume. One 50 kg bag of cement is about 0.035 m³ loose. A box of 350 × 350 × 300 mm has a volume of 0.35 × 0.35 × 0.30 = 0.03675 m³, close enough (checked by script; the 0.035 m³ bag figure is a general rule of thumb). Fill the box level and strike off the top. Do not use a shovel count: shovels vary.

For a 1 : 3 : 6 mix with one bag of cement you need 3 boxes of sand and 6 boxes of stone. For 1 : 2 : 4 you need 2 boxes of sand and 4 boxes of stone.

Silt test for sand

Take a clear straight-sided jar or bottle. Put in sand to about 5 cm.
Add clean water to about twice the depth of the sand.
Shake hard for a minute. Let it settle for about 3 hours.
Look for a thin, lighter layer of fine silt and clay on top of the sand. Measure it with a rule.
FAO's block-making text says a silt layer above 3 mm in the test is too much. Ask your trainer to read the FAO page with you to confirm the method and the limit.
If the sand fails: wash it, or change the sand supplier. Write the date, source and result in your logbook.

Mix a batch of concrete by hand

Clean a hard, flat mixing board or concrete floor. Wet it lightly so it does not drink the water.
Fill the gauge box with sand, level and strike off. Spread the sand on the board.
Add the cement bag (or fraction) on top. Turn the dry mix at least 3 times with the shovels until the colour is even (turning detail: not verified from a cited text).
Add the stones. Turn again until even.
Form a crater. Pour in part of the water. Turn the edges into the middle. Add water slowly until the mix is workable and holds together without running. Do not drown it.
Place it within 2 hours of adding water. Never add water to a stiff mix to make it workable again.
Wash tools and the board at once. Clean up wet cement.

Block making (sandcrete) at yard scale

The figures below are Nigerian (NIS 87:2007, as reported by Structville) for a 225 mm hollow block, 28 days. They are foreign figures to show how mix and strength relate. Ghana commonly uses blocks of 150 mm thickness.

Mix (cement : sand)	Sand per bag	Blocks per bag	Strength at 28 days
1 : 6	3 wheelbarrows (12 head pans)	15	5.6 N/mm²
1 : 7	3.5 wheelbarrows (14 head pans)	17	4.2 N/mm²
1 : 8	4 wheelbarrows (16 head pans)	20	3.5 N/mm²
1 : 9	5 wheelbarrows (20 head pans)	25	3.3 N/mm²

The Nigerian standard sets a minimum of 2.5 N/mm² for non-load-bearing and 3.45 N/mm² for load-bearing blocks. A 1:8 mix is recommended in that source.
Blocks per bag differ with the size of the block. For 150 mm blocks the number per bag is not verified; find it by making a trial batch.
In Sekondi-Takoradi, 90 blocks from 30 makers had crushing strength well below the recommended level; most makers used 1:6 or a richer mix, so the failure was in the making and curing, not only the mix; GSA did not seem to sample blocks. Check the block before you build with it.
A KNUST study found strength above 7.0 N/mm² possible with a 1:12 mix when the materials, making and curing were right.

Make 10 blocks by hand

Check the sand with the silt test. Set out the mould on a clean, flat, hard base.
Batch the mix, for example 1 bag : 16 head pans of sand (1:8) for a trial. Measure the head pan or gauge box carefully.
Mix dry, then add water slowly. The mix should hold when you squeeze it in your fist, and crumble when you press it with a thumb. Do not make it sloppy.
Fill the mould in 2 or 3 layers, tamp each layer, strike off the top, and lift the mould straight up.
Leave the block in the shade, on a flat surface, and do not move it for 24 hours.
Cure: sprinkle with water from the day after casting for about 2 weeks (14 days at least), keep them wet but not under running water. Remove any cover after about 48 hours, but keep wetting.
Let blocks dry before use. Damp blocks shrink and crack in the wall.
Count how many blocks you got from the bag and the sand. Write it in your logbook.

The block drop test. A common field check is to drop a block from waist height onto hard ground: it should not shatter. This is general practice and not verified; it does not replace a crushing-strength test at a lab. Ask the maker for the mix ratio and the curing days. Buy only blocks that have cured for at least 14 days.

Reinforcement basics (read the drawing)

You do not choose bar sizes. The engineer gives the bar size, number, spacing and cover on the drawing. Your job is to place them exactly. Bar sizes, cover thickness and bed-joint reinforcement practice in Ghana were not verified; follow the drawing.

Steel bars carry pulling forces. Concrete carries pressing forces.
Clean bars: remove loose rust and dirt before placing. Do not use bars with oil or paint.
Cover: the layer of concrete between the bar and the outside face. It protects the steel from rust. The drawing gives the cover; use spacer blocks (small concrete blocks or purpose-made spacers) to hold the bars off the formwork.
Lap and bend: do not cut or bend bars on site unless the drawing says so and the supervisor shows you how.
Tie wire holds bars in place while you pour. Do not weld rebar unless an engineer and a welder approve.
Place bars where the drawing says (for example, a lintel carries main bars near the bottom). A bar in the wrong place gives a false sense of safety.

Formwork awareness

Formwork (shuttering) is the temporary mould that holds wet concrete in shape until it hardens. You may build simple formwork for a lintel, a small beam or a column under supervision.

Sides and soffit (bottom) of the right size and straight, with joints tight so no cement paste leaks
Inside face clean and lightly oiled with form oil or old engine oil (never use oil on the bars)
Props or struts at about 1 m centres under a lintel box (prop spacing for lintels; foreign UK practice)
Props on firm, level ground, braced so they cannot move
Level checked with a spirit level along and across
Reinforcement in place with spacers and cleaned
Nothing loose inside (wire, nails, wood shavings)

Stripping time. Do not remove props or formwork early. Safe stripping times depend on the element and the weather and were not verified here: ask the engineer, and keep the concrete wet for several days.

Batching and block yard sums

A gauge box holds 0.035 m³. A mix of 1:2:4 uses one bag. How many boxes of sand and of stone?
You make blocks at 1:8 with 20 blocks per bag. How many bags and wheelbarrows of sand for 600 blocks?
A strip footing is 0.675 m wide, 0.225 m thick and 30 m long. What is its volume?
Using the rule of thumb that dry materials are about 1.5 times the wet volume (not verified), and that 1 bag of 1:3:6 makes 0.35 m³ of dry materials, how many bags does that footing need?

Silt test at home

Collect sand from two different places. Do a silt test on each. Record the silt layer and say which is better for plastering and why. Photograph the jars.

Check yourself: Unit 2

Name two things you must not do to a concrete mix after 2 hours.
Why do you cure blocks and concrete?
Who decides the bar size in a lintel?

Unit 3 · Quality walls: openings, arches, reinforced and retaining walls, DPC and movement joints

A wall is only as strong as its weakest joint, and the weakest place is usually around a door or a window.

Competency standard

Learning outcome	Performance criteria — the trainee…
3.1 Build openings	forms a door and a window opening to size, plumb and square, with a lintel bedded correctly
3.2 Build a simple arch	marks an arch on a template and lays the blocks or bricks to it
3.3 Build to an engineer's drawing	places columns, tie beams and bars as drawn, and knows when to stop and ask
3.4 Build a low retaining wall awareness	names the parts and the checks for a wall that holds soil
3.5 Place a DPC and a movement joint	lays a DPC level at the right height and leaves a movement joint where the drawing shows

Range. Single-leaf sandcrete walls up to one storey, to a drawing. Evidence. A built opening and lintel; an arch template and arch; a DPC check; observation.

Quality in the wall: a fast check

Corners and leads plumb, level and to the gauge rod
Bed and head joints full, about 10 mm, and tooled
Every course level along and across; line pins not sagging
Bond kept: half-block overlap in stretcher bond
Openings the right width and height; frames plumb
Wall height per day limited (see below)
DPC in the right place; lintels bedded 150 mm each end

Daily lift. In the UK, BS 5628-3 limits the wall height above a lintel to about 1.5 m in 24 hours so the fresh mortar is not squashed. For ordinary walls a lift of about 1.2 to 1.5 m a day is common practice and not verified for Ghana.

Doors and windows

Read the plan: the width and height of the frame, the sill level and the position along the wall (centre or distance from the corner).
Mark the opening on the gauge rod: the sill height and the lintel underside.
Use a line and plumb: leave the opening the frame width plus about 10 mm each side for packing and plumbing. This clearance is common practice and not verified; check the frame maker.
Build both sides (the reveals) plumb. Check with a spirit level every two courses. Where a block would be cut, use a cut block at the middle of the wall piece, not next to the corner.
Set the frame in place before the lintel course. Prop it plumb. Do not force it.
Build up to the lintel level.

Lintels

A lintel carries the wall over an opening.

Bearing: at least 150 mm on each end, bedded in mortar and level along and across. Prop at about 1 m centres while the lintel is curing or under construction. That UK guide also describes cavity trays and weep vents for cavity walls; they do not apply to single-leaf sandcrete walls.
Length = opening width + 2 × 150 mm bearing. A 1.2 m window needs a lintel at least 1.5 m long; a 1.0 m door needs 1.3 m (arithmetic checked).
Cast-in-place lintel: box the sides and soffit (see Unit 2), place the bars exactly as drawn, pour 1:2:4 concrete, and keep it wet. Do not load it until it has cured. Bar size and cover: from the engineer's drawing only.
Precast lintel: buy or cast on the ground, cure fully before lifting. Lift with two people, mark the "this side up".

Build a window opening with a lintel

Mark the sill and lintel heights on the gauge rod.
Build one side of the opening up to sill level, plumb. Repeat on the other side.
Fix the frame (or a temporary template of the frame width) with props.
Continue each side up to the underside of the lintel, checking plumb and the exact width at the top, middle and bottom with a tape.
Set a level bed of mortar on both sides. Place the lintel with 150 mm bearing each end. Check level along and across with a spirit level.
Prop the lintel if it is cast in place or if the supervisor says so.
Continue the wall above the lintel with half-block overlap, within the daily lift limit.
Record the opening width, height and lintel length in your logbook.

Arches (a small segmental arch)

An arch carries load by pressing sideways into its supports (the abutments). A segmental arch is part of a circle. You build it on a wooden support called a centering or former, and remove the former when the mortar has hardened.

Work out the radius. If the span (opening) is c and the rise (how high the arch goes above the springing line) is h, the radius of the arc is R = c² ÷ (8h) + h ÷ 2. For a span of 1.2 m and a rise of 0.2 m: R = 1.44 ÷ 1.6 + 0.1 = 1.0 m (checked by script; example numbers).

Make an arch template and build a small arch

Draw the opening on a flat board: a horizontal line 1.2 m long (the springing line).
At the middle, mark a point 0.2 m above the line (the rise).
Hammer a nail 1.0 m below the high point on the centre line. Tie a string 1.0 m long to it. Hold a pencil at the other end and swing the arc through the high point to both ends of the springing line.
Saw along the line with a jigsaw or hand saw. Cut two boards (one for each face) and nail them to a spacer board between the faces: this is the centering.
Prop the centering at the springing line height, level, with props at both ends. Check the level.
Lay the arch units (bricks, or small cut blocks) from both ends toward the middle. Cut them so that the joints point to the centre of the circle (the nail). The joints should be thin at the bottom and thicker at the top, within about 10 mm.
Fit the last unit (the key) in the middle, bedded fully in mortar.
Keep the mortar damp. Leave the centering in place until the mortar has hardened, at least several days (ask the supervisor).
Lower the centering by removing the props evenly. Check the arch for movement.

Arches over wide openings, doors, or any opening carrying a floor or roof are for a mason with experience and an engineer's design. Use a lintel instead if in doubt. Heights of walls above arches and the size of the abutments were not verified.

Reinforced walls: columns, tie beams and confined masonry

In many Ghanaian buildings, concrete columns at the corners and tie beams (also called ring beams) at floor and roof level tie the walls together. Free training books on this style, called confined masonry, exist (for example, How to build safer houses with confined masonry) but their licence was not stated, and Ghana practice for steel in sandcrete walls was not verified. For this reason:

Build columns and tie beams only to an engineer's drawing.
Build the wall with "toothing" where a column will go (alternate blocks projecting), so the concrete locks in. Brace the wall while it is being built.
Never pour a column without the bars, the cover and the formwork checked by the supervisor.
For a block with cores, steel bars in cores filled with concrete may be shown on a drawing. Do not add steel that the drawing does not show.

Low retaining walls (awareness)

A retaining wall holds back soil. Soil is heavy, and wet soil is heavier, so the wall must be designed.

Parts: the footing (base), the stem (the wall), weep holes or a drain behind the wall, and a back-fill of gravel or clean stone. Weep holes and gravel back-fill are common practice and were not verified from a cited source here.
Water is the enemy. Poor drainage is a common cause of retaining wall failure in general. Make sure rain water drains away.
Height: any retaining wall higher than about 1 m, or one near a building, a road or a slope, needs an engineer. This 1 m rule is the book's safe rule, not a law.
Never stand or work in front of a retaining wall you are building, or a trench next to one, without a safe edge plan. See Unit 6.

The damp proof course (DPC)

The DPC stops damp rising from the ground into the wall.

Place it at least 150 mm above finished ground level, bedded between two layers of mortar on the first course (a Ghana supplier listing and a UK reference say the same).
Lay it level, lap joints, and do not let it be pierced by sharp stones.
A Ghana study of 14 test walls over four years found that damp-proof coatings and dense concrete bases performed better than polythene sheet DPCs. Ask the engineer which DPC the building needs.
Common fault: plaster or screed running past the DPC and bridging it, so damp rises behind. Stop the plaster at the DPC, or follow the drawing.

Movement joints

Walls, floors and plaster expand and shrink with heat, damp and settlement. A movement joint is a planned gap, filled with a flexible material, so that the wall can move without cracking. Long walls, changes of height or foundation, and joins between old and new work are typical places for one. The positions and the filler material for Ghana sandcrete walls were not found in the sources used. Rules from Ghana were not verified: put movement joints exactly where the engineer's drawing shows, and do not bridge them with plaster.

Openings and arches

A window is 1.5 m wide and 1.2 m high. How long is the lintel (150 mm bearing each end)? A door is 0.9 m wide: how long is its lintel?
An arch has a span of 1.8 m and a rise of 0.3 m. Find the radius.
A wall has a 150 mm lintel bearing. A lintel is 1.5 m long. What opening width does it suit?
After the first day, the wall above a lintel is 2.0 m high. What is the problem?

Opening survey

Look at three buildings in your town. For each, sketch one door or window. Note if there is a lintel or an arch, and whether you can see cracks above it. Bring your sketches and photographs.

Check yourself: Unit 3

How much must a lintel rest on the wall at each end?
How high above the ground should the DPC be?
Who tells you where to put a movement joint?

Unit 4 · Plastering finishes, floor screeds, tile bedding awareness, crack diagnosis and repair

A good plaster job is mostly what you do before the plaster and after the plaster. The middle is the easy part.

Competency standard

Learning outcome	Performance criteria — the trainee…
4.1 Plaster a wall in two coats	prepares the wall, sets guides, applies base and finish coats and cures them
4.2 Produce a chosen finish	floats, sponges or textures the finish coat to a sample
4.3 Lay a floor screed	sets levels, lays and finishes a screed and cures it
4.4 Prepare a base for tiles	leaves a flat, clean, sound screed and knows what a tiler needs
4.5 Diagnose and repair cracks	tells moving cracks from stable ones and repairs a stable crack

Range. Internal and external walls of sandcrete blocks; a small floor slab up to about 20 m². Evidence. A plastered panel; a screeded floor; a crack diagnosis sheet; a repaired crack; observation.

All plastering steps below are foreign practice from Indian, Irish and American sources combined with the FAO block text. Check the engineer's specification.

Mixes and thickness

Item	Figure	Source
Cement plaster, two coats	1:5, each about 5 mm (FAO small-building text), at least 24 hours between coats, wet the wall first, never in direct sun	FAO Blocks
Internal, single coat	about 12 mm	IS 1661
Ceiling	about 6 mm	IS 1661
External, two coats	15 to 20 mm in total; base about 12 mm at 1:5, finish about 8 mm at 1:4	IS 1661
Cement-lime for crack control	1:1:6	IS 1661
Floor finishing coat	1 cement : 2 to 4 sand, 1 to 2 cm, on a cleaned and wetted slab	FAO Blocks

The sources do not agree. One supplier says 1:4 for internal and 1:6 for external plaster. Ghana has no single official plaster ratio in the sources used. Ask your site engineer for the mix and use a gauge box to keep it constant. If a coat is thicker than about 15 mm, apply it in two coats.

Wall preparation, step by step

Plaster a 2 m × 2 m panel in two coats

Tools: steel float, wooden float, plastering trowel, hawk, straight edge (rod) 2 m, plumb rule, scratcher or comb, wet brush or sprayer, buckets, gauge box.

Wait. Let the wall's mortar harden first. Typical waiting time is several days to weeks (general practice, not verified).
Check the wall. It should be dry, clean and free of dust, oil and loose bits. Rake out the joints about 10 mm deep so the plaster keys into them.
Brush off the dust and wet the wall evenly so it does not suck water out of the plaster. The surface should be damp but not running.
Set the guides (screeds). Fix vertical strips of mortar or timber at the two edges of the panel, plumb with a plumb rule and at the thickness you want. Use a spirit level or plumb bob. The guides are your depth control (general practice; not verified from a cited source).
Mix 1:5 with the gauge box. Mix to a stiff, workable paste.
Base coat about 12 mm outside (about 5 mm for the FAO two-coat method). Throw or trowel the mortar firmly onto the wall from the hawk. Fill between the guides.
Rod off. Draw the straight edge up the wall, moving it side to side, resting on the guides. Fill hollows, cut off high spots. Repeat until flat.
Scratch the surface with a scratcher or comb to give a key. Do not smooth it.
Cure the base coat. Spray lightly morning and evening for 48 hours before the finish coat. Keep it out of direct sun and wind.
Finish coat about 8 mm at 1:4 after the base has firmed up (at least 24 hours). Wet the base lightly first. Apply from the bottom up in strips. Rod flat.
Float. When the surface loses its shine and your thumb leaves only a light print, rub with a wooden float in circles to close small cracks. Then use a steel float for a smooth finish.
Cure for about 7 days by keeping it damp. Poor curing leads to scaling and cracking.
Check: tap the surface; a hollow, drummy sound means poor bond. Hack it off and redo it.

Safety. Wear gloves, safety glasses and dust mask when mixing and when hacking off old plaster. Wash cement from the skin at once with clean water. Wet cement can burn the skin (general safety practice; not verified from a cited source). Do not plaster above 2 m from a ladder or a trestle that you have not checked. See Unit 6.

Finishes you can offer

Finish	How
Smooth steel-float	Steel float over a firm, wooden-floated surface; do not overwork or you bring up water and weaken it
Wooden float (sandy)	Rub with a wooden float in circles; good under paint
Sponge finish	Rub with a damp sponge float when slightly firm
Scratch or comb key	Scratch with a comb when the base coat is still soft, to bond a second coat
Textured or roughcast	Throw a wet mix from a small brush; a trade skill: practise on a board first

The textures above are common trade practice and were not verified from a cited source; a sample board shown to the client avoids arguments.

Common plaster faults

Fault	Likely cause	Fix
Hollow sound (drummy)	Poor bond; dusty or dry wall	Hack off and redo
Map cracking	Mix too rich, too wet or not cured	Cut out; replace with correct mix; cure
Dusty, weak surface	No curing (dried too fast)	Cure; or seal
Wavy surface	No guides or straight edge	Rod off; add a skim to fill
Damp at the base	No DPC, or plaster bridging it	Check DPC (Unit 3); stop plaster above DPC
Efflorescence (white salt)	Salts in sand, water or block; damp	Dry brush; fix the source of damp; do not wash with a lot of water

Some practice notes here were not individually verified.

Floor screeds and floor finishing

A screed is a layer of sand-cement mortar laid on a concrete slab to give a flat, level surface.

FAO suggests a finishing coat of 1 cement : 2 to 4 sand, 1 to 2 cm thick, on a cleaned and moistened slab. Thin toppings crack. Casting the slab to its finished level is often better. Thicker bonded screeds (about 25 to 40 mm), the falls (slope) for wet areas and bay sizes were not verified: ask the engineer.
Use a semi-dry mix (like damp sand that holds when squeezed) for a screed so that it shrinks less.
A bonding coat (cement slurry painted on the wet slab just before the screed) helps the screed grip. Method details: common practice; not verified.

Lay a 1.5 m × 2 m screed panel

Tools: straight edge (rod) 2.5 m, steel float, wooden float, spirit level, level pegs or bats, brush, tape, bucket, gauge box.

Prepare the slab. Clean off dust, oil and loose bits. Wet it until damp. No standing water.
Set levels. Fix level pegs or lines of mortar bats (screed bays) at the finished screed height from your datum. Use the water level (Unit 1) to match pegs.
Mix at 1:3 (cement : sand), semi-dry. Use the gauge box.
Brush a thin slurry (cement and water paste) onto the wet slab, only as far ahead as you can screed in the next few minutes.
Lay the mortar between the bats, slightly above them, and compact it with the back of a shovel or a wooden float.
Rod off. Use the straight edge, resting on the bats, in a sawing motion. Fill hollows and re-rod.
Float. Rub with a wooden float. When the surface has no shine and a finger leaves a small print, steel-float it once. Do not overwork.
Remove the bats and fill the gaps with mortar, float again.
Cure by covering with damp sacks or plastic and sprinkling, for about 7 days (similar to plaster; not verified for screed). Keep traffic off for at least 3 days (general; not verified).
Test: place a 2 m straight edge on the floor. The gap under it should be small (the maximum gap depends on the finish; ask the tiler or the engineer). Check levels with the spirit level in both directions.

Tile bedding awareness (tiling is a separate trade)

Tiling is taught in the HSM Floor and Wall Tiling course. As a mason, your job is to hand over a sound, flat, clean, level base that the tiler can work on.

Screed cured fully (ask the tiler how long; do not tile on a green screed)
Surface flat and level with the straight edge
No dust, oil, curing compound or loose bits
Falls to drains (if any) set as drawn
Door sill and threshold heights agreed with the tiler
Plaster on walls finished plumb and dry, and stopped at the right height

Crack diagnosis and repair

Not every crack is a repair job; some are a warning.

Type	Looks like	Likely cause	What to do
Hairline in plaster	Thin, random, map-like	Drying shrinkage, too much water, poor curing	Fill after the wall has dried; usually safe
Straight, vertical or stair-step crack	At a joint, may widen	Settlement, a weak footing, movement	Monitor; call the engineer if it grows
Diagonal from a corner of a door or window	Starts at a corner of the opening	Stress at an opening, a missing lintel, settlement	Call the engineer
Horizontal crack	Along a joint	Pressure from soil, a roof thrust or a poor wall	Call the engineer: do not just fill it
Crack through a lintel	In the lintel	Overloaded or poorly made lintel	Support the wall; call the engineer
Crack on both sides of the wall (through the wall)	Visible inside and out	Movement of the wall	Call the engineer
Crack that keeps growing	Wider after a week or after rain	Active movement	Call the engineer

These are summaries only. Settlement cracks, horizontal cracks, cracks through lintels, cracks on both sides of a wall and cracks that are still growing: get an engineer; do not just fill. Of the Ghana collapses studied, the common human causes were no soil investigation, poor design, bad materials, weak supervision and incompetent contractors. A 2026 Adenta collapse report found serious regulatory breaches, structural deficiencies and unsafe construction practices (preliminary).

Watch a crack

Take a photograph with a tape beside the crack, and write the date.
Draw a pencil line across the crack at both ends and write the date, or fix a small glass or plaster strip across it (a tell-tale, general practice; not verified).
Measure the width at three places with a ruler or crack gauge.
Check again after one week, after a heavy rain, and after a month. Write the readings in your logbook.
If the crack has grown, or is any of the dangerous types above, stop and call the engineer.

Repair a stable crack in plaster

Tools and materials: pointing trowel, cold chisel or the corner of a trowel, wire brush, brush, bucket of water, cement, fine sand (and PVA bonding agent or a flexible filler if the supervisor says so).

Check first that the crack is stable (see the previous practical) and is only in the plaster.
Cut out loose material and widen the crack slightly into a V shape, so the filler grips.
Clean out all dust with a brush.
Wet the crack lightly.
Fill in thin layers with mortar (1:3 or 1:4) or a flexible filler, pressing it in. Leave it a little proud.
Finish flush with a float after it firms up.
Cure damp for several days.
Mesh over cracks to hold them is used by some trades: not covered by the sources read here (not verified).

Plaster and crack sums

A wall is 4.0 m × 2.5 m with a window 1.2 m × 1.0 m. How many m² need plaster on one side?
A plaster coat 12 mm thick covers 20 m². What is the volume of mortar? Using 6 bags per m³ for 1:5 mortar and adding 20% for waste, how many bags of cement?
You see a diagonal crack from the corner of a window that was 1 mm wide last week and 3 mm now. Do you fill it?
List two reasons a plaster sounds hollow when tapped.

Crack walk

Walk around your town or village and photograph three cracks in walls (with permission if on private land). Say what kind each looks like (use the table) and what you would do. Do not give advice to a house owner unless you are sure; say "call an engineer" if in doubt.

Check yourself: Unit 4

Which cracks should you not just fill?
How long should you cure plaster?
What does a hollow sound mean?

Unit 5 · Estimating, quantities, pricing and quoting small jobs

A good mason who cannot price a job works hard and stays poor. Learn to count before you quote.

Competency standard

Learning outcome	Performance criteria — the trainee…
5.1 Measure areas	works out net wall area, floor area and volumes from a drawing
5.2 Count blocks, mortar and sand	calculates blocks with waste, and bags of cement and sand for mortar, plaster and screed
5.3 Price a job	adds materials, labour, transport, contingency and profit
5.4 Write and agree a quote	writes a clear quotation with payment stages and a drawing

Range. A small room, a fence wall, a plastering job. Evidence. A completed estimate; a quotation; sums checked.

The basic method (general practice)

Measure the job from the drawing and, if possible, on site.
Work out the net area: gross area minus openings.
Work out materials with waste allowances.
Work out labour (your time and your helpers').
Add transport, overheads, a contingency and profit.
Write it clearly on a quotation and agree payment stages.

The method is general business practice; Ghana quote templates were not found. Mark every price "example" until you get your own.

Facts for the sums

Item	Figure	Source
Blocks per m² of wall (450 × 225 mm face, 10 mm joints)	1 ÷ (0.46 × 0.235) = 9.25 (9.88 without joints)	Search summary Blocks per m2 (arithmetic checked)
Waste on blocks	add 5 to 10% (we use 7.5%)	Search summary Blocks per m2
Mortar volume per m² of wall	100 mm wall 0.008 m³; 150 mm wall 0.011 m³; 200 mm wall 0.015 m³	FAO Blocks
1:5 cement mortar	6.0 bags of cement and 1.1 m³ of sand per m³ of mortar	FAO Blocks
Cement bag	50 kg	Structville Sandcrete

The "1 bag per 100 blocks" rule heard on site was not verified. Sources disagree between 0.35 and 3 bags. Do a trial wall to find your own figure.

Worked example 1: a wall (from the sums in Level 1)

A wall 10.0 m long and 2.7 m high has a door 2.1 × 1.0 m and a window 1.2 × 1.2 m.

Gross area = 10.0 × 2.7 = 27.0 m².
Openings = 2.1 + 1.44 = 3.54 m². Net area = 23.46 m².
Blocks = 23.46 × 9.25 = 217.0. Add 7.5%: 233 blocks.
Mortar (150 mm wall) = 23.46 × 0.011 = 0.258 m³. At 6.0 bags: 1.55 bags. Sand = 0.258 × 1.1 = 0.28 m³.
Compare with the rule of 1 bag per 100 blocks (233 blocks gives 2.3 bags): order the higher figure, then check against your real use after the first job. (Example numbers; checked by script.)

Worked example 2: a small room (quotation)

A room 4.0 m × 3.0 m (outside, centre line perimeter 14.0 m), wall height 2.7 m, one door 2.1 × 1.0 m, two windows 1.2 × 1.2 m each. Floor area 12 m². All prices below are example prices; replace with three local quotes.

Step 1. Areas.

Gross wall = 14.0 × 2.7 = 37.8 m². Openings = 2.1 + 2 × 1.44 = 4.98 m². Net wall = 32.82 m².
Plaster both sides (ignoring reveals) = 2 × 32.82 = 65.64 m².
Screed = 12 m² at 20 mm.

Step 2. Materials.

Item	Working	Quantity
Blocks	32.82 × 9.25 = 303.6; + 7.5% = 326.4	327 blocks
Block mortar	32.82 × 0.011 = 0.361 m³; × 6.0 = 2.17 bags; × 1.1 = 0.40 m³ sand	2.17 bags (2.38 with 10% extra); 0.40 m³ sand
Plaster (12 mm, 1:5)	65.64 × 0.012 = 0.788 m³; × 6 = 4.73 bags; + 20% = 5.67 bags; sand 0.788 × 1.1 × 1.2 = 1.04 m³	5.67 bags; 1.04 m³ sand
Screed (20 mm)	12 × 0.02 = 0.24 m³; × 6 = 1.44 bags; + 20% = 1.73 bags; sand 0.24 × 1.1 × 1.2 = 0.32 m³	1.73 bags; 0.32 m³ sand
Cement total	2.38 + 5.67 + 1.73 = 9.78	10 bags; order 11 (spare)
Sand total	0.40 + 1.04 + 0.32 = 1.76 m³	order 2 m³

The plaster and screed bags use the 1:5 figure from FAO; a richer 1:4 or 1:3 mix needs more cement, so add the 20% allowance for waste and key (the 20% is an example allowance).

Step 3. Costs (example prices).

Item	Working	GH¢
Blocks	327 × 5	1,635
Cement	11 × 110	1,210
Sand	2 m³ × 300	600
Materials		3,445
Labour: blockwork	32.82 m² × 45	1,476.90
Labour: plaster	65.64 m² × 25	1,641.00
Labour: screed	12 m² × 30	360.00
Labour		3,477.90
Transport and delivery	example	250
Subtotal		7,172.90
Contingency 5%	7,172.90 × 0.05	358.65
Profit 15%	(7,172.90 + 358.65) × 0.15	1,129.73
Quote		8,661.28 (about GH¢8,660)

Per m² of floor area: 8,661.28 ÷ 12 = GH¢721.77 (example). (All sums checked by script.)

Step 4. Payment stages (example). 40% before starting (GH¢3,464.51 on 8,661.28), 40% when walls and lintels are finished, 20% on handing over after plastering and a joint check. Never start without the deposit; never hand over the last 20% of work before payment, unless you have agreed otherwise in writing.

Where example prices come from, and what is real. Real Ghana benchmarks seen: a 6-inch hollow block GH¢3.50 to 5.50 in Greater Accra in Q2 2026, a national benchmark of GH¢6.20, and asking prices on Jiji of GH¢5 to 10 (undated). Cement GH¢101 to 118 a bag in Greater Accra in 2026 is a weak snippet and its source is unclear. Takoradi prices were not found: ask three local suppliers and write the date. A blockwork labour benchmark of about GH¢213 per m² in Greater Accra is reported but may include materials and is not verified. A cost for plastering, flooring and painting a single room and porch together was GH¢8,000 to 13,000 in a 2026 estimate. Plasterer pay was listed at GH¢1,543 to 6,665 net a month at the start of a career, with the basis of calculation not stated. Treat all as rough guides.

Do a real estimate

Take the plan of a small room or a boundary wall (ask a mason or find one in the class).
Measure the walls and openings. Calculate the net area.
Calculate blocks with 7.5% waste, mortar bags and sand using the FAO figures.
Phone three local suppliers for the prices of blocks, cement and sand and write the date and name.
Work out materials, labour at a rate you choose, transport, contingency and profit.
Write a one-page quotation (see below) and swap with a partner, who checks the arithmetic.

Writing a quotation

Your name, phone, the client's name, the date and the site address
What the job is, with a drawing or dimensions attached
What is included (materials, labour, transport) and what is not
The price in GH¢, the payment stages and the dates
How long the job will take, and what holds it up (rain, late payment, missing materials)
What happens if the client changes the plan (extra price in writing)
Guarantee: for example, you will repair faults from your own work for an agreed period
Signatures of both people

These items are good practice; Ghana quotation templates were not found. For a very large or official contract, a lawyer or the Assembly should advise. Contractor classification (D and K grades, by capital, turnover, equipment and personnel) applies to tenders, and the Ministry's current class thresholds for building contractors were not found; individual masons need no licence in the sources read.

Estimate a wall

A boundary wall is 8.0 m long and 2.4 m high with one gate opening 2.1 × 0.9 m and one window 1.2 × 1.0 m (a service hatch).

Find the net area.
How many 450 × 225 mm blocks (with 10 mm joints), adding 7.5% for waste?
How many bags of cement and cubic metres of sand for the mortar in a 150 mm wall? (Use 0.011 m³ of mortar per m² and the 1:5 figures.)
If blocks cost GH¢5 each, what do the blocks cost?

Price a real job

Choose a real job you have seen (a fence, a step, a room). Measure it, make an estimate with local prices, and write a one-page quotation. Keep the prices and dates in your logbook.

Check yourself: Unit 5

How many blocks (without waste) go on 1 m² of 450 × 225 mm blocks with 10 mm joints?
Why add a waste allowance?
Name three things that go into a quotation price besides materials.

Unit 6 · Working at height, scaffolds, quality control and supervising a helper

Falls and bad blocks cost more than any machine. The best mason is the one whose walls, and whose people, are still standing.

Competency standard

Learning outcome	Performance criteria — the trainee…
6.1 Work safely at height	uses ladders correctly and checks a scaffold before use; knows when not to climb
6.2 Control quality	tests sand and blocks, records mixes and cures, and checks work against the drawing
6.3 Supervise a helper	gives clear instructions, shows the job, checks the work and keeps the helper safe
6.4 Keep records and handle faults	keeps a mix and cure log, a snag list and handover notes

Range. A single-storey job with one or two helpers. Evidence. Ladder and scaffold check; quality log; supervision observation; snag list.

The law, in short

The Labour Act 2003 requires an employer to give workers safe working conditions, safety appliances and protective equipment at no cost to the worker (section 118); workers who reasonably believe there is imminent danger may leave and report it (section 119); and serious accidents must be reported within seven days (section 120). Ghana's Factories, Offices and Shops Act 1970 covers construction operations in some summaries, but an accident reporting section was not verified. Many workers on small construction sites are informal and unprotected. A new safety law was still being prepared in 2026 and was not yet in force when this book was written. If you are the person in charge, you carry responsibility for your helper.

PPE and daily hazards

Safety boots (steel toe), gloves (cement burns), dust mask and eye protection for cutting and mixing, long sleeves, hard hat under scaffolds or on multi-storey sites, knee pads for floor work; knee pads are the author's suggestion
Lifting: a 50 kg bag is heavy. Bend your knees, keep your back straight, share a heavy lift
Sun and heat: water, shade, a hat, rest breaks
Cement: it burns. Wash at once, remove wet clothes (general safety practice)
Cuts and dust: blocks cut with a bolster and club hammer throw chips: wear glasses

Ladders

Angle: 1 in 4: 1 m out for every 4 m up (about 75°). A ladder reaching 3.6 m up the wall has its foot 3.6 ÷ 4 = 0.9 m from the wall.
Extend at least 1 m above the landing. Do not stand on the top three rungs. Do not stand ladders on bricks or pallets.
Tie the ladder; place it on firm level ground; face the rungs; three points of contact; one person climbing.
Check it before every use. A ladder with a split rung is thrown away.
A ladder is for short jobs. For long work on a wall, use a scaffold or a platform with a rail.

Scaffolds: awareness, not erection

Do not erect a scaffold above 2 m unless you are trained, and do not use one that has not been checked. Ghana scaffold rules and local pole practice were not verified. These checklist points are foreign:

Standing on firm ground with base plates, not on loose blocks or soft soil
Platforms fully planked, no gaps or damaged planks, planks overhanging the supports by about 150 to 300 mm (US figure: 6 to 12 in)
Guard rail, mid rail and toe board on open edges (toe board height differs between sources: about 150 mm or 3.5 in)
Braced against movement; ties to the building if the height-to-base ratio is above 4 to 1
Do not climb the cross braces; use a proper ladder
Inspected before use by a competent person; unsafe scaffolds are tagged and not used
Material not piled on the platform; no loose tools

If you are not sure, do not climb. A scaffold built from unsecured poles or planks without rails is a death trap. Tell your supervisor, and ask for a safe scaffold or work from the ground. Falls, strains, cement burns and dust are the main hazards on a masonry site.

Ladder and scaffold check

Inspect a ladder with a checklist: feet, rungs, side rails, locks, damage. Tag any fault.
Set up the ladder at the 1-in-4 angle on firm ground. Tie it.
Climb with three points of contact. Do not carry tools in your hands: use a bag.
With the trainer, walk round a real scaffold or a picture of one, and mark the faults with the checklist above.
Write a short report on what you found.

Quality control: the five checks

Quality control means checking the work at each stage, not at the end.

Materials in: cement fresh, sealed bags; sand silt-tested; blocks cured and checked; water clean.
Mixes: same gauge box, same water; mix recorded in a log with the date.
Work in progress: plumb, level, square, line, bond, joints, gauge rod.
Curing: a curing log shows who wetted the work and when.
Handover: a snag list before the client sees the work.

The Kumasi study found site concrete well below the minimum, water judged by eye, little curing or testing, and segregation and honeycombing. A record of mixes and curing is cheap protection. Cube tests (concrete cubes crushed in a lab) are a way to prove strength; they were rarely done on those sites. Slump tests are used by engineers; the method is not covered here (not verified).

Keep a quality log

Make a table in your logbook with: date, task, mix, gauge box used, water added, weather, who mixed, who cured.
Fill it in for every concrete or mortar batch you make this week.
Take three photographs of the work in progress: before, during and after curing.
Do a "snag list" walk of a finished wall with the supervisor: write every fault (plumb, joint, crack, damaged block, stain), who fixes it and by when.

Supervising a helper

You are now the person who tells someone else how to do a job. Be clear, patient, safe.

Plan the day. Tell the helper the job, the amount, the tools and the time.
Show first. Do one block, one sweep or one batch yourself, slowly, then let the helper try while you watch.
Say it simply. One instruction at a time. Ask the helper to say it back.
Keep safe. Check boots, gloves and mask before work. Tell the helper where not to go (edges, under loads).
Check early. Look at the first few blocks, the first mix, the first square metre. Correct at once and kindly.
Give feedback. Say what is good, then what to change, in private if possible. Never shout or insult.
Pay fairly and on time. Agree the rate before the work.
Be respectful. Sexual harassment of a helper or an apprentice is not acceptable, and a worker may end the contract. Women in masonry report harassment and male-dominated training as barriers.
Report accidents to the client or employer. Give first aid and call for help.

Supervision and safety scenarios

A helper is climbing a scaffold with no top rail. What do you do?
Your helper has put 6 buckets of water into a mix meant for 4. What do you do?
You find a hollow-sounding patch in yesterday's plaster. Who fixes it, and what do you tell the client?
A ladder is 4.8 m up the wall. How far out should the foot be?

Toolbox talk

Prepare a five-minute talk on one safety topic for a helper (cement burns, ladders, lifting, dust). Give it to a family member or a classmate. Write what they said back.

Check yourself: Unit 6

How far out is the foot of a ladder that reaches 4.0 m up a wall?
Name two checks you do on a scaffold before using it.
Why show a helper the job before letting them do it?

Unit 7 · Location, small business ideas, marketing and access

Skill earns respect. Pricing, a clean phone message and a finished-job photo earn the next job.

Competency standard

Learning outcome	Performance criteria — the trainee…
7.1 Choose a location	names settings in the Western Region that give good returns and why
7.2 Plan a small masonry business	prices a job and plans services
7.3 Market yourself	uses WhatsApp Business, a Google profile, signs, referrals and a portfolio
7.4 Include everyone	plans work and customer service for people with disabilities

Range. An independent mason or small gang. Evidence. Business plan; price sheet; portfolio; oral questions.

What the market looks like

Block laying and tiling make up a large share of building work. Over 60% of a building site's workforce is tied to it. Most learn by informal apprenticeship with no formal standards, and employers hire on trial.
Masonry is among 15 trades where demand is expected to outpace supply; construction employs 3.5% of working young people, 91% of them informally.
Plasterer pay in a 2026 listing was GH¢1,543 to 6,665 net a month at the start and GH¢2,217 to 10,801 after five years, but how it was calculated is not stated.

Location settings that give good returns

Takoradi, Sekondi and Tarkwa: housing, shops and hospitality building (growth areas; not verified from a source here)
Along the coast road to Akwidaa and Busua: guest houses, boundary walls and tourism building. Use only washed sand: salt in beach sand weakens concrete (general; not verified)
New housing estates and plots: fences, boundary walls, plastering and floors
Near a block yard or a sand and stone supplier: low delivery cost
Near markets and schools: repair, rendering and maintenance work
Within reach of your tools and helpers: a safe store for cement, away from rain

Business ideas and ingenuity

Idea	What you need	Note
Labour-only subcontractor (per m² or per block laid)	tools, a helper	Lowest risk. The client supplies materials
A small gang (mason, 2 to 3 labourers, apprentice) on contract	a supervisor (you), PPE	Needs a deposit and a plan
Supply and labour for fences and boundary walls	working money for materials	Price carefully: example in Unit 5
Plastering and repair service	trowels, floats, ladders	Steady work; good photos help
Floor screeds and tile bases (with a tiler)	a straight edge, floats	Partner with tilers
Block-making yard	mould, cement, sand, curing space	Capital heavy; the cement alone at the example price (GH¢110 a bag, 20 blocks a bag) is GH¢5.50 a block, as much as the Accra price range of GH¢3.50 to 5.50. Do the sums before you start. A lean mix is a weak block
Estimates and quotes for others	a phone, a tape, a calculator	Charge a small fee; add value

These models are the author's judgement; there is no Ghana source for them. Registration steps, tax and bookkeeping for a business are covered in Level 3.

Money maths: what does a day earn?

Example (all numbers are example). You lay blocks at GH¢45 per m² (labour only). You and one helper lay 25 m² of wall in a week.

Income = 25 × 45 = GH¢1,125.
You pay the helper GH¢400 for the week, and spend GH¢120 on transport and tools.
Profit for you = 1,125 − 400 − 120 = GH¢605 for the week.
A 15% profit margin on the GH¢1,125 job income is 1,125 × 0.15 = GH¢168.75.
If it rains for two of the six working days, income falls. Plan a "rain day" cushion.

Price and plan

You charge GH¢45 per m² for blockwork. You complete 38 m² in a month. What is your income? You pay a helper GH¢350 a week for 4 weeks. What is left?
Supply-and-labour price for a wall: blocks 9.25 × 1.075 × GH¢5 = ?; cement 0.011 m³ × 6 bags × GH¢110 = ?; sand 0.011 × 1.1 × GH¢300 = ?; labour GH¢45. What is the price per m²?
A client asks you to start with no deposit. What do you say?

Market yourself

Use WhatsApp Business: a business profile with your hours and address, a catalogue and automatic greeting and away messages.
Set up a free Google Business Profile so people searching nearby find you; verification can be by phone, email, video call or a postcard that takes about 14 days.
Portfolio: photograph each job before, during and after, with a tape in the shot to show size. Add the price per m² and, with permission, a client comment.
Signboard: your name, your trade, your phone number, "Blockwork · Plastering · Floors".
Referrals: ask satisfied clients to tell neighbours; give a small thank-you.
Be honest. Never claim a qualification you do not hold. Never claim an engineer's skills.

Accessibility

The Persons with Disability Act, 2006 (Act 715) is the law on disability rights; reports say public facilities still do not follow it fully. Programmes such as YIEDIE have aimed to help persons with disabilities build entrepreneurial skills in construction. Which tasks are workable (the author's judgement; not from a source) depends on the person: seated and bench work such as pointing and finishing, mixing small batches, hand-making blocks with a mould at table height, cutting blocks at a bench, estimating, quoting, drawing, supervising and WhatsApp marketing. Heavy carrying and scaffold work are not workable for many people. Adjustments that help: raised work tables; a wheelbarrow or cart with a helper for lifting; lighter hollow blocks (150 mm); clear, large-print and picture quotes; voice notes and video calls for people who cannot read or have low vision; written notes for people who are deaf; step-free access in your workshop or office. Women who choose masonry may face harassment; some programmes have trained women, including YOTA/NVTI for 200 women and a GIZ Female Talents in Construction cohort, and Plan International's PASEWAY trained over 4,200 youth in construction and hospitality. Only 2 to 6% of female trainees in one programme chose masonry-type trades.

My masonry business plan

Choose a business idea and a location near you.
Write the price of one job (use Unit 5), your helper costs and your monthly profit.
Set up a mock WhatsApp Business profile and sketch a signboard.
Take a before-and-after photo of a small job and write a short caption.
Add one accessibility step to your plan.

Price visit

Visit two block yards or hardware shops. Write the price and size of blocks, cement and sand and the date. Compare them with the prices in this book.

Check yourself: Unit 7

Name two ways to let people find your masonry business.
Why is a deposit important?
Name one adjustment that helps a mason who uses a wheelchair.

Glossary

Term	Meaning
Competent / Not Yet Competent	The two possible results of a CBT assessment
Plan, elevation, section	Drawing views: from above, from the side, and cut through
Scale	How much smaller the drawing is than the real thing (1:50)
Profile boards	Boards on stakes outside the building that carry the setting-out lines
Datum	A fixed reference height from which all levels are measured
Gauge rod	A marked timber showing course heights and openings
Strip foundation	A long, narrow concrete base under a wall
Gauge box	A bottomless box of known volume for measuring materials
Silt test	A jar test for fine dirt in sand
Water-cement ratio	Weight of water divided by weight of cement
Curing	Keeping concrete or plaster damp so it hardens properly
Formwork	A temporary mould that holds wet concrete
Cover	Concrete between the steel and the outside face
Lintel	A beam over a door or window
Abutment	The support at each end of an arch
Centering	The temporary former on which an arch is built
DPC	Damp proof course: a layer that stops damp rising
Movement joint	A planned gap to let a wall or floor move without cracking
Screed	A layer of sand-cement mortar for a flat, level floor
Key	A rough surface that helps plaster stick
Rod off	Draw a straight edge over fresh plaster to flatten it
Snag list	A list of faults to fix before handover
Contingency	Money kept aside for surprises

Logbook

Copy these pages into an exercise book. Your logbook is part of your assessment evidence.

Unit 1: scale sums; setting-out record with diagonals; level check; gauge rod
Unit 2: silt test record; concrete batching record; blocks made and cured; formwork check
Unit 3: opening and lintel record; arch template; DPC check; opening survey
Unit 4: plaster panel record; screed record; crack diagnosis sheet; crack watch readings
Unit 5: an estimate; a quotation; price list with dates and suppliers
Unit 6: ladder and scaffold check; quality log; snag list; toolbox talk
Unit 7: business plan; portfolio photos; price visit notes
Every homework, dated

Self-check quiz

A line measures 12 cm on a 1:50 plan. How long is it on site?
What must be true of the two diagonals of a square-set rectangle?
How high is a wall of 12 courses of 225 mm blocks with 10 mm joints?
What do you check in a sand sample, and how?
What mix would you use for a reinforced lintel, according to the foreign training text used here?
How long should blocks cure, at least?
How much must a lintel rest on the wall at each end?
Who gives the bar size and spacing in a lintel or column?
How long do you cure plaster, and why?
Which cracks should you not just fill?
What are the net wall area and number of blocks (with 7.5% waste) for a wall 10 m × 2.7 m with a door 2.1 × 1.0 and a window 1.2 × 1.2?
How far out is the foot of a ladder that reaches 4.8 m up a wall?