Carpentry and Furniture Making Level 2

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

Bridge from Level 1: what you already know

Level 1 did not cover reading drawings, making a framed door or a window, using power machines, building carcasses with hinges and drawers, roof carpentry, estimating a whole job or writing a quote. 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.

Honesty rule. Numbers marked example were invented to teach the method. Where a Ghana fact could not be found, the book says not verified. Typical practice means master-carpenter practice that no source in this book confirms: your trainer checks it. The arithmetic in every worked example was checked by a computer script.

Three rules for every job in this book. (1) Measure twice, cut once, and check square with the diagonals. (2) Safety is a gate: an unsafe act is a Not Yet Competent. (3) Write down the price before you cut the first board.

Competency standard

Range. A door, a window, a table, a cabinet, a wall of built-in shelves. Evidence. Drawing; cutting list; setting-out check; oral questions.

The kinds of drawing you will meet

A set of drawings for a house is a bundle of pictures of the same building from different directions. Learn these names (typical practice).

Scale and dimensions

A drawing is smaller than the real thing, so it uses a scale. A scale of 1:20 means 1 unit on paper is 20 units in real life. Common scales are 1:5 or 1:10 for details, 1:20 for a piece of furniture or a room, 1:50 or 1:100 for a whole building (typical practice).

Converting a scale. Real size = drawing size × scale number. A room 4.2 m long is 4,200 mm. At 1:20 it is drawn 4,200 ÷ 20 = 210 mm long. To go the other way, a line 85 mm long on a 1:10 drawing is 85 × 10 = 850 mm in real life. This is how a door 850 mm wide appears 85 mm wide on a 1:10 drawing.

Common lines and symbols (typical practice)

From drawing to cutting list

A cutting list is a table of every part you must cut. It is the bridge from a drawing to the workshop. For each part write: name, number, thickness × width × length, timber or board. Add a margin for planing and trimming, and write the finished size and the rough size.

Worked example (example): a small side table, top 600 × 600, height 700, legs 45 × 45 mm.

Check: do the parts add up to the overall size? Here the legs are 700 mm long and the top is 25 mm thick and sits on the legs, so the finished table would be 725 mm high, not 700. Either shorten the legs to 675 mm or change the drawing. A good cutting list catches this before you cut.

Setting out: making the real job match the drawing

Setting out means marking the real size and position of a job on timber, on a board, or on the ground. These are the steps to make sure the job is square, plumb and level.

Tools and materials: pencil, marking knife, steel tape 5 m, 600 mm rule, try square, large square, long straight edge, chalk line, spirit level, plumb bob, clear hose for a water level, string, pegs, a setting-out rod (a straight, flat batten, about 25 × 50 mm and as long as the largest dimension, planed on one face). Buy battens and pegs at a timber yard. Ghana local tool names: ask your Hub carpenter.

The setting-out rod

A rod is a stick that carries all the important measurements of one job. You mark the rod once and then use it again and again, so each part is the same, and you do not read the tape on every cut.

1. Plane one face of a straight batten flat.
2. Draw the section or the elevation of the job full size (1:1) on the rod: for a door, the stile height, the rail positions, the lock height and the hinge positions.
3. Mark each measurement with a knife line, not a thick pencil line. Write a letter by each line.
4. Always measure from the same end, and label the end.
5. Transfer measurements from the rod to the timber with a square. Do not read the tape twice.

Making a rectangle square: the 3-4-5 rule

If the sides of a triangle are 3, 4 and 5 units, the corner opposite the 5 is a right angle. This works in any unit (the rule comes from Pythagoras: 3² + 4² = 5², that is 9 + 16 = 25).

1. Mark the first line (the base) with a string or chalk line and put a mark A at the corner.
2. Measure 600 mm along the base from the corner and put a mark B.
3. From the corner, measure and mark the second line roughly at right angles, and put a mark C at 800 mm.
4. Measure from B to C. It should be 1,000 mm. If it is more, the corner is too open. If less, too tight. Move C sideways until it is exactly 1,000 mm.
5. For a big job on the ground use 3 m, 4 m and 5 m (or 6, 8, 10 m). The bigger the triangle, the smaller the error.

The diagonal check

The two diagonals of a true rectangle are equal. Always check them after you set out a rectangle, and after you glue up a frame.

Example: a rectangle 2,400 mm × 1,800 mm. Each diagonal = √(2400² + 1800²) = √(5,760,000 + 3,240,000) = √9,000,000 = 3,000 mm (this is a 3-4-5 triangle times 600). If one diagonal reads 3,000 and the other 3,012, the frame is racked by 12 mm: push along the long diagonal to square it.

For a door 850 × 2000 mm, the diagonal is √(850² + 2000²) = √(722,500 + 4,000,000) = √4,722,500 = 2,173 mm (rounded). Two diagonals within 2 mm of each other means the door is square enough to hang (typical practice).

Level and plumb

• Level means flat from side to side. Use a spirit level on a straight edge, or a water level made from a clear hose filled with water (the water finds the same height at both ends).
• Plumb means straight up and down. Hang a plumb bob, or use a spirit level on a vertical post.
• Datum line is a level line at a known height (often 1 m above the finished floor) from which all heights are measured. Mark it around the room with a water level or a long level.

Check yourself

1. What does a scale of 1:20 mean?
2. Why do you check the diagonals of a frame?
3. What are the three numbers of the square-making rule, and what do they make?

Competency standard

Range. A single leaf panelled or framed door; a simple frame; a casement window. Evidence. Finished door and frame; practical observation; oral questions.

Choose the timber

• For doors and windows, choose a durable species that stays flat. Odum, teak and emire are the usual choices in the Level 1 notes: FAO rates odum very durable (550 to 660 kg/m³) and teak durable (580 to 820 kg/m³), and emire is used for joinery. Odum is scarce and over-exploited, and Ghana restricts its harvest. Ghana plantation teak of about 12 years has been judged suitable for furniture, door frames and window frames.
• Wawa is light and easy to work and is used for panel filling and interior joinery, but it is rated non-durable and weak to insects, so it should not be the outside frame in the weather without protection.
• Buy legal timber. Buy from a registered yard that can say where the wood came from and give you a receipt. Do not buy rosewood. Chainsaw-milled lumber is the main domestic supply but chainsaw milling for sale is illegal under the Timber Resources Management Act 1997 (Act 547). What a small carpenter must legally hold to buy domestic timber was not verified: ask the Forestry Commission in Takoradi.

Moisture: why doors warp

Timber swells when it takes in water and shrinks when it dries. A door made from wet timber will shrink, twist and open gaps after you hang it. Seasoning dries timber evenly, with the least distortion, to a moisture level close to the surrounding air. Sheltered outdoor timber in Takoradi settles at an equilibrium moisture content of about 18% over a year, the highest of 21 Ghanaian towns measured. Rooms with air conditioning dry timber lower. Wood should be worked at about the moisture of the place where it will live (typical practice). Air drying alone reaches only about 20%.

Check the timber before you use it (typical practice).

1. Sight along the edge: close one eye and look along the board for a bow, a spring or a twist (winding).
2. Check the face on a flat bench or with two straight edges for twist: the two edges at the ends must look parallel.
3. Look for cracks, splits, knots at the joints and soft or blue-stained patches.
4. If a moisture meter is available, take readings in 3 places. Moisture-meter price in Ghana: not found.
5. Stack the boards flat in the workshop for several days with small spacers between them, so air passes all round, before cutting (typical practice; sticker spacing and drying time not verified). Seal the end grain with paint or wax to slow cracks (typical practice).

Door types and parts

Framed doors use mortise and tenon joints.

Typical sizes and clearances (example, trainer to check)

Measure the opening in three places (top, middle, bottom for the width; left, middle, right for the height) and also its diagonals. Use the smallest width and height. Build the door and frame to the real opening, not the drawing, and write the measurements on the cutting list.

Cutting list for the framed door (example)

An example door: 850 × 2000 × 40 mm, two stiles, three rails, two plywood panels. Lengths of rails include tenons of 50 mm at each end (so the shoulder-to-shoulder width is 650 mm).

The openings between the rails are 600 mm (upper) and 950 mm (lower): 2000 − 100 − 150 − 200 = 1550 = 600 + 950. A panel needs room to move in the groove, so do not glue a solid-wood panel in; ply is more stable.

Timber volume (net): stiles 2 × 0.04 × 0.10 × 2.0 = 0.016 m³; top rail 0.003 m³; middle rail 0.0045 m³; bottom rail 0.006 m³. Total 0.0295 m³. With a 25% allowance for waste and planing this is 0.0369 m³ (about 15.6 board feet). Unit 6 prices this door.

Mortise and tenon for the door

A tenon is a tongue; a mortise is the slot it fits in. Rules of proportion:

• The tenon is about one third of the rail thickness. For a 40 mm rail that is about 13 mm (example).
• A haunch is a short extra bit at the top of the tenon that stops the stile from twisting and fills the groove. Ask your trainer for the size for your door.
• Leave a horn (a spare length of the stile) at the top of each stile, so the stile does not split when the mortise is chopped. Cut the horn off after glue-up.
• A wide rail (such as the 200 mm bottom rail) is better with two narrower tenons than one wide tenon (typical practice).

Mortise and tenon steps are in Level 1 and in Fairham Joints, which tells you to mark with a knife and square, saw the tenon cheeks on the waste side of the line, remove the haunch, bore out the waste of the mortise with a twist bit and then chop it with a chisel and mallet in small steps from each edge towards the centre.

Making and fixing the door frame

A door frame has two jambs (the sides), a head (the top) and, for outside doors, a threshold (the sill). A door stop is a thin strip fixed to the frame that the door shuts against.

Frame joints: the head is joined to the jambs by a housing, halving or mortise and tenon joint (typical practice). The horns on the jambs at the head stay long until fixed to prevent damage.

Hanging the door

Hinges. Three hinges per door for a 2000 mm door (typical practice). Set the top hinge about 150 mm from the top of the door and the bottom hinge about 225 mm from the bottom, and put the third in the middle (typical practice). Leave the screws long enough to hold in the frame, not just in the surface.

Fix the common faults.

A simple casement window

A casement window has a fixed frame and one or two sashes (the opening parts) that hang on hinges. The frame has a head, two jambs and a sill. The sill slopes outwards so water runs off, and has a drip groove underneath so water drops clear of the wall (typical practice).

Check yourself

1. Why do you not glue a solid-wood panel tight in its groove?
2. How many hinges does a 2000 mm door usually have, and where is the third?
3. A frame has diagonals of 2,170 and 2,176 mm. What do you do?

Competency standard

Range. A circular saw bench (or a hand-held circular saw), a planer or planer-thicknesser, and a router, fitted with guards. Evidence. Induction record; observation of a safe cut; checklist; oral questions.

The big hazards

The core controls for woodworking machines are fixed guards, a riving knife and anti-kickback devices, push sticks, local dust extraction and trained operators. Where fixed guards alone cannot prevent access to the dangerous part, use guards together with push sticks, jigs and holders. Adjustable guards sit as close to the work as possible.

The ten rules for any machine (typical practice, trainer to check)

1. Sign-off first. No sign-off, no use.
2. Dress safely. Tie long hair back. No loose sleeves, ties, scarves, rings, bracelets or hanging necklaces. No gloves near a rotating cutter, because a glove can be pulled in. Wear enclosed shoes.
3. PPE. Eye protection, ear defenders, and a dust mask for sawing and sanding.
4. Check before you switch on. Guards in place, blade or cutter sharp, tight and the right type, fence locked, cord undamaged, floor clear, light good.
5. Isolate to change a blade. Switch off, take the plug out or lock the isolator, wait until the cutter has stopped, then change it. (See Workplace Safety Level 2 for lockout.) Guards are adjusted only with the machine stopped.
6. Hold the work firmly. Use a fence, a clamp, a jig, a push stick or a push block, never your bare hand close to the cutter.
7. Let the machine reach full speed before the cut. Do not force the timber. Let the cutter do the work.
8. Never reach over a running cutter. Never clear off-cuts with your hand. Use a stick, after the machine stops.
9. Never leave a running machine. Switch off and wait until the cutter stops before you walk away.
10. Report a fault straight away and tag the machine out of use.

The circular saw bench

A circular saw bench has a blade that comes up through a table. It rips timber along the grain against a fence, and cuts across the grain with a cross-cut guide. It is among the most dangerous machines in the shop.

Parts to know: table; blade; crown guard (covers the blade from above); riving knife (a thin steel plate behind the blade that keeps the cut open so timber does not pinch the blade); fence; cross-cut guide; push stick; on and off switches; dust extraction.

Push stick rules from the UK HSE code as quoted in a school risk assessment:

• The push stick is at least 450 mm long.
• Use it for any cut under 300 mm and for the last 300 mm of a longer cut.
• Keep your hands never closer than 300 mm to the blade.
• Guards stay in place when you use a push stick.

The hand-held circular saw

A hand-held circular saw is lighter than a bench saw but can still kick back.

1. Clamp the board so it cannot move. Support the part that will fall away.
2. Set the depth so the blade goes only a little below the timber (about one tooth, typical practice) and the guard moves freely.
3. Rest the saw's base on the board before you start the blade. Let it reach full speed.
4. Use two hands and keep your body to one side of the cut line. Keep the cord behind you, away from the blade.
5. Feed steadily. If the blade slows, ease off and do not force it.
6. Release the trigger and wait for the blade to stop before you lift the saw.

The planer and thicknesser

A surface planer makes one face and one edge flat and square. A thicknesser makes the other face parallel to the first, to a set thickness. Many workshops have a combined planer-thicknesser.

The router

A router is a motor that spins a cutter (bit) to make grooves, rebates, edge shapes and joints. Use it only with the trainer.

Dust and health

Control dust at the source by extraction. Vacuum or wet-sweep instead of blowing. Wear a dust mask (an FFP2 or N95 type, typical practice) when sanding or sawing. Work with doors open. Never leave dust on top of an electrical box or near a flame. If your cough does not go away or you get skin rashes, see a health worker.

First aid for a cut

Call for help at once (112 is the emergency number used in Workplace Safety; confirm with your trainer). This is not a first-aid certificate: train with St John or the Red Cross.

1. Press firmly on and around the wound with a clean pad or cloth. Squeeze the edges together if you can.
2. Raise the injured part above the heart, unless a bone may be broken.
3. Cover with a pad and bandage. If blood soaks through, add another pad on top; do not remove the first.
4. Do not pull out an object stuck in the wound; press on either side of it.
5. Check the bandage is not too tight: press a nail for 5 seconds; if the colour does not return within 2 seconds, loosen it.
6. Do not give food or drink.

These are Australian guides (foreign). For a cut-off finger or a part, no readable source was found: get help at once and do not delay for tidying up.

Power costs (example)

A 1.5 kW machine used 3 hours a day for 24 days a month uses 1.5 × 3 × 24 = 108 kWh. At an example price of GH¢1.50 a kWh, that is 108 × 1.50 = GH¢162 a month. (The real tariff was not verified: look at your bill. Add this to your overhead in Unit 6.)

Check yourself

1. How long must a push stick be, and when must you use it?
2. What does a riving knife do?
3. When can you change a router bit?

Competency standard

Range. A wall cabinet; a two-door wardrobe; a drawer; a single or double bed. Evidence. Finished cabinet, drawer and bed corner; practical observation; oral questions.

Solid timber or panel boards?

(The comparison of strength and movement is typical practice. On dust: Source: HSENI Woodworking.) Ghana prices were not found: phone your yard.

Carcase construction: the box

A carcase is the box of a cabinet or wardrobe: two sides, a top, a bottom (or plinth), a fixed shelf, adjustable shelves and a back. The back is thin ply (6 mm) and fixed all round, because it keeps the box square.

Dowel rules. A dowel in a blind hole needs an escape path for the glue and air: plane a small flat on the side of the dowel or buy grooved dowels, or the wood may split. A usual dowel diameter is about one third of the board thickness (typical practice; standard sizes not found). So 18 mm board takes 6 mm dowels (example). Use a drilling jig or dowel centres for matching holes.

Pilot holes and screws. Drill a pilot hole smaller than the screw so the wood does not split, and countersink for flat heads (typical practice). A countersink bit cuts a conical recess for the screw head.

The wardrobe: a worked example

A two-door wardrobe, 1,200 mm wide × 2,000 mm high × 550 mm deep, from 18 mm ply, with a 6 mm back (example).

How many sheets? A sheet is 1,220 × 2,440 mm (= 2.9768 m²). Lay the parts out on paper first (a cutting plan):

• Sheet 1: two sides, 550 wide each: 2 × 550 = 1,100 ≤ 1,220, and 2,000 ≤ 2,440. Fits.
• Sheet 2: top, bottom, shelf, each 550 × 1,164. Two strips of 550 wide across the sheet (1,100 ≤ 1,220); each strip is 2,440 long and holds two parts (2 × 1,164 = 2,328 ≤ 2,440). Four places for three parts. Fits.
• Sheet 3: the two doors, 600 wide each: 1,200 + saw cuts ≈ 1,204 ≤ 1,220; and 1,980 ≤ 2,440. Fits.
• 6 mm sheet: back 1,200 × 2,000 fits one sheet.

So you need 3 sheets of 18 mm ply and 1 sheet of 6 mm ply. Area check: parts = 2 × (0.55 × 2.0) + 3 × (0.55 × 1.164) + 2 × (0.6 × 1.98) = 2.2 + 1.9206 + 2.376 = 6.4966 m², against 3 × 2.9768 = 8.9304 m², so 72.7% is used and 27.3% is waste, enough to cut shelves later. Allow a few millimetres for the saw cut (the kerf) between parts.

Build a carcase: steps

Doors and hinges

Overlay doors sit on the front of the carcase and cover its edges. Inset doors sit inside the opening and need very exact gaps, so start with overlay.

Types of hinge.

• Butt hinge: two flat leaves with a pin. Fitted in recesses (like a door hinge in Unit 2). Strong; used for timber doors.
• Concealed (cup) hinge: a metal cup fits in a round hole (typically 35 mm across) bored in the back of the door, and an arm screws to the carcase. Adjusts in three directions and is easy to align. Use the hinge maker's drilling template for the position (typical practice).

How many hinges? A door about 1 m high takes 2; a taller door takes 3 or more (typical practice). On a 1,980 mm wardrobe door we use 3 per door (6 for the pair), as in the cost example.

Drawers

A drawer is a box that slides in an opening. The box has a front, a back, two sides and a bottom (6 mm ply in a groove). Joints at the corners are dovetails (the classic), or a simple rebate and screw (or dowel) joint for a strong, cheaper drawer. A through dovetail shows end grain on both faces; a slope of about 1:6 is used for softwoods and 1:8 for hardwoods, with 1:7 as a compromise, and the strength does not change with the slope. Dovetails are used on drawers because they resist being pulled apart.

A hand-cut dovetail: no readable step-by-step source was found for this book. Your trainer demonstrates. The usual order (typical practice): mark and cut the tails on one piece, transfer them to the end of the other piece with a knife, cut the pins between the lines, and test the fit.

Sizing the drawer. The drawer box must be smaller than the opening so it slides without sticking. Metal runners need a set side clearance (many take about 12.5 to 13 mm per side; typical practice, follow the maker's data sheet). Wooden runners need about 1.5 to 2 mm of clearance per side (typical practice). Example: the opening inside the carcase is 764 mm wide. With 13 mm per side for runners, the drawer box is 764 − 2 × 13 = 738 mm wide (example).

The bed

A bed frame has two long side rails, a head rail (headboard) and a foot rail, with slats across and centre supports if the bed is wide. Beds are best made as knockdown (KD) furniture, so they can be taken apart for transport, with bed bolts or bed brackets (metal fittings). Knockdown furniture is a documented sector in Ghana, but producers lack knowledge of seasoning and finishing and face rising costs for equipment, labour and materials.

Size. Measure the mattress, then make the inside of the frame a few millimetres larger (typical practice). The example below is for a mattress about 1,400 × 1,900 mm (example; mattress sizes in Ghana were not verified: measure the real mattress).

Check yourself

1. Why is the thin back of a cabinet fixed all round?
2. Why does a dowel need an escape path for the glue?
3. What is a knockdown bed?

Competency standard

Range. A model king post truss at ground level; a small timber mould for a concrete slab. Evidence. Model truss; geometry sheet; oral questions.

Why this matters

Falls from height cause about 26% of construction fatalities, a figure from UK HSE statistics quoted in the trade press. A truss is heavy, has a high centre of gravity, and can fall over before it is fixed. These are foreign sources (Australia, New Zealand, UK). No Ghana figure was found.

Parts of a roof (a simple pitched roof)

The king post truss is the simplest: a central post, two rafters and a tie beam. Factory-made trussed rafters are a way to build roofs for housing in developing countries, but the UNIDO report is not a code of practice.

Roof geometry: the maths you can do safely

A roof is made of triangles. Use Pythagoras: (rafter)² = (run)² + (rise)². The run is half the span; the rise is the height from the tie beam to the ridge.

Worked example 1 (model truss). A model truss with a span of 600 mm and a pitch of 30°. Run = 600 ÷ 2 = 300 mm.

• Rise = run × tan 30° = 300 × 0.5774 = 173.2 mm.
• Rafter length = run ÷ cos 30° = 300 ÷ 0.8660 = 346.4 mm.
• Check: 300² + 173.2² = 90,000 + 30,000 = 120,000; √120,000 = 346.4 ✓.

Worked example 2 (a 3-4-5 roof). A roof with a run of 2 m and a rise of 1.5 m. The rafter is the hypotenuse of a 3-4-5 triangle times 0.5: 2.5 m. The pitch is arctan(1.5 ÷ 2) = 36.9°.

Worked example 3 (roof area for estimating). A building plan 6 m × 4 m with a 30° pitch (example): the sloping area is the plan area ÷ cos 30° = 24 ÷ 0.8660 = 27.7 m². This is only for estimating the area of roof covering (before overhangs and overlaps). Do not use it to size timber.

Working at height: what the regulators say (foreign sources)

• Nobody should stand on the top plate of an external wall to install trusses without fall protection. If you work from an internal plate, keep at least 1.5 m from the external walls. Wall frames higher than 2 m need edge protection.
• A written safe work method statement is required in Victoria, Australia, for truss erection above 2 m or with a crane.
• For ladders see the 1-in-4 rule and the three points of contact in Workplace Safety Level 2.

Build a model king post truss at ground level

Tools and materials: 25 × 50 mm battens (wawa or softwood), 6 mm ply for gusset plates (small triangular plates that hold joints), PVA glue, screws or small nails, a saw, a try square, a sliding bevel (an adjustable angle gauge), a protractor, a pencil, a flat floor or a table.

Formwork awareness

Formwork (shuttering) is the temporary mould that holds wet concrete until it hardens. Carpenters make it for slabs, beams, columns, steps and drains. It is not furniture: it has to hold a very heavy, wet material without moving, and it must be tight so the cement paste does not leak out. Concrete forms are covered in the free US Army carpentry manual FM 5-426, but the scanned PDF could not be read in full for this book, so its details are not repeated here.

Mixing concrete and pouring are masons' jobs (see Masonry and Plastering). Here you only make the mould.

Check yourself

1. What does the tie beam of a truss do?
2. Who sizes the timbers of a real roof truss?
3. Can a trainee work on a roof in this course?

Competency standard

Range. A door and frame; a wardrobe; a bed. Evidence. Estimate sheet; quote; oral questions.

Measuring timber

Timber is sold by the piece, by the cubic metre (m³), or by the board foot (BF). Ghana's price units (per piece, per m³, per plank) were not verified: ask the yard what it sells by and write the answer down.

Cubic metres. Volume = thickness × width × length, all in metres.

Board foot. 1 board foot is a piece 1 ft × 1 ft × 1 in, which is 144 cubic inches or 0.002359737 m³. The formula is BF = thickness (in) × width (in) × length (ft) ÷ 12.

Nominal and true size. Planed softwood is priced by its nominal size: a "2 × 4" is really about 1.5 × 3.5 inches. The nominal 8 ft piece is (2 × 4 × 8) ÷ 12 = 5.33 BF, but the true volume is (1.5 × 3.5 × 8) ÷ 12 = 3.5 BF, so the nominal figure is about 52% bigger than the real timber. Know which one you are paying for.

Examples of pieces per m³ (worked, example sizes).

• A piece 50 × 100 × 2,400 mm: 0.05 × 0.10 × 2.4 = 0.012 m³. One m³ holds 1 ÷ 0.012 = 83.3 pieces. Each piece is 0.012 ÷ 0.002359737 = 5.09 BF.
• A board 25 × 150 × 3,000 mm: 0.025 × 0.15 × 3.0 = 0.01125 m³; 88.9 boards per m³; 4.77 BF each.

Waste

Cutting, planing, bad knots and mistakes all waste timber. A planning figure of 15% to 25% is typical (typical practice; not verified). Use more for hardwood with defects and for small, many-part jobs. Waste allowance: needed timber = net volume × (1 + waste %).

The ten steps of an estimate

1. List every part from the cutting list (Unit 1).
2. Work out the net volume of each part (T × W × L).
3. Add them up for the net total.
4. Add the waste (for example 25%).
5. Change to the sizes the yard sells (pieces or boards) and round up to whole pieces.
6. List the hardware (hinges, locks, bolts, screws, handles, rails) and consumables (glue, sandpaper, finish, edge tape).
7. Estimate the labour (days × day rate).
8. Add overhead (rent, power, blade sharpening, tool wear, transport): a share of each job.
9. Add profit.
10. Write the quote.

Worked example 1: timber for the door and frame (example prices)

From Unit 2: the door's net volume is 0.0295 m³. With 25% waste it is 0.0295 × 1.25 = 0.036875 m³ (15.6 BF).

The door frame (example): two jambs 50 × 100 × 2,100 mm and a head 50 × 100 × 950 mm: 2 × 0.05 × 0.10 × 2.1 + 0.05 × 0.10 × 0.95 = 0.021 + 0.00475 = 0.02575 m³. With 20% waste it is 0.0309 m³.

At an example price of GH¢3,500 per m³ (not a real price: replace it with a yard's price):

• Door timber: 0.036875 × 3,500 = GH¢129.06.
• Frame timber: 0.0309 × 3,500 = GH¢108.15.
• Timber total: GH¢237.21.

To buy it as 25 × 150 × 3,000 mm boards: 0.036875 ÷ 0.01125 = 3.28, so buy 4 boards for the door (round up). The frame needs 50 mm timber, bought separately.

Worked example 2: a quote for the door and frame (example)

A deposit of 50% is GH¢529.46.

Markup and margin: do not mix them up

Markup is profit as a percentage of cost. Margin is profit as a percentage of the price. In the example above, a 20% markup gives a profit of 176.49 on a price of 1,058.92, so the margin is 176.49 ÷ 1,058.92 = 16.7%. A 25% markup is a 20% margin (25 ÷ 125). If you want 20% of the price as profit, mark up by 25%.

Worked example 3: the wardrobe quote (example prices)

The 2-door wardrobe in Unit 4 needs 3 sheets of 18 mm ply and 1 sheet of 6 mm ply.

A 60% deposit is GH¢1,718.48; the balance on delivery is GH¢1,145.65. (The deposit pays for the board and hardware you must buy first; 50% to 60% is typical practice, not a rule.)

What a quote must say

Keep the minimum wage in mind. The national daily minimum wage for 2026 is GH¢21.77. That is a floor, not a fair pay for a trained carpenter. The day rate of GH¢100 in these examples is an example only.

Hidden costs

Check yourself

1. How many cubic metres is a piece 50 × 100 × 2400 mm?
2. What is the difference between markup and margin?
3. Name three things a quote must say.

Competency standard

Range. A small workshop, an on-site carpentry service, or a repair and polishing service. Evidence. Business plan; break-even sheet; portfolio; oral questions.

What the market looks like

• A 2016 study of 300 Ghanaian timber firms found the main problems of the furniture industry were the continuing decline of preferred traditional timbers and competition from imported furniture. 85% of manufacturers hardly used lesser-used species; 44% of those said they lacked information on the species' properties.
• A Ghanaian study of knockdown furniture found weak knowledge of seasoning and finishing, and little adoption of new technology.
• The Ghana Standards Authority and FORIG announced testing and certification of imported and locally made furniture before sale. The Authority says it has developed or revised 21 wood-industry standards with UNIDO. The list and GS numbers were not found: ask the Ghana Standards Authority.
• What this means for you (inference): a carpenter who knows seasoning, finishing and legal timber has an edge over one who does not.

Location settings that give good returns

What a workshop needs (typical practice). Noise that neighbours can tolerate; dust control; a secure store for timber and tools; power; a dry floor; good light; space for long boards; and a fire extinguisher. Local council permit and fire rules for a workshop were not verified: ask the STMA and the Ghana National Fire Service.

Business ideas and ingenuity

Legal timber is part of the business. Buy from a registered yard that can say where the wood came from and keep receipts. Do not buy rosewood: the harvest and export have been banned and it is listed under CITES. Chainsaw milling for sale was outlawed in 1997, and illegal lumber is a seizure risk. Current enforcement in 2026 was not verified.

Registration. The Registrar-General's fee for a sole-proprietor business name is GH¢130 with GH¢70 a year to renew. Tax, SSNIT and permits are covered in Level 3.

Money maths: break-even (example)

Fixed monthly costs (example): shop rent GH¢400, electricity GH¢150, blade sharpening GH¢60, phone data GH¢50. Total = GH¢660. One table (example): price GH¢600; materials GH¢250; a helper's pay GH¢100. What is left for you and your fixed costs is the contribution: 600 − 250 − 100 = GH¢250. Break-even = fixed costs ÷ contribution per item = 660 ÷ 250 = 2.64, so you must sell 3 tables a month before you make a profit. At 8 tables: 8 × 250 − 660 = GH¢1,340 (example).

Market yourself

Accessibility

Customers. The Persons with Disability Act, 2006 (Act 715) is the law on disability rights; reports say public facilities still do not follow it fully. In your workshop: a step-free route to the door and the counter, large print prices and pictures, WhatsApp voice notes and video for customers who cannot read or have low vision, written messages for deaf customers, and a place to sit while they choose.

Workers. Carpentry has many tasks that people with disabilities can do, and some they cannot do safely:

• Hand-tool tasks, drawing, setting out, sanding, finishing, upholstery, quoting and sales can suit many people, including wheelchair users and some people with hearing or vision limits, with adjustments.
• Heavy lifting and machine work carry limits: this depends on the person and the machine, so decide together, not for them.

Adjustments that help:

• Seated bench height. A wheelchair-user bench was built with its top about 74 cm from the floor, with low-profile face vices so the user can roll under, while many shop benches are about 86 cm, which may be too high for seated use. Machines at the wrong height, even by a few centimetres, make a difference. These are magazine and forum sources, not Ghana standards.
• Fit the person. Reach, grip and transfers matter as much as the chair: let the worker help design the bench to their own measurements (inference). An occupational therapist can advise.
• Jigs and holders (typical practice): a stop block and clamp so one hand can saw, a bench hook, a planing board, a raised or angled work surface, and supports for long boards.
• Deaf or hard of hearing workers (typical practice): mark danger zones with paint, use a visual stop signal (a light or a flag) for machines, and check that machine noise cannot hide a warning. Ghana disability-inclusive carpentry guidance was not found.
• Training should be given in a way each worker can follow, as the Labour Act requires training suited to the worker. Ask your District Assembly about help for disabled entrepreneurs: reports said the Assemblies' disability share would rise to 5% from 2026, but this was not verified for this book.

Check yourself

1. Name two things a workshop needs in a good location.
2. If fixed costs are GH¢800 and each item leaves GH¢200, how many items to break even?
3. What must you never do with timber species in your marketing?

1. A 1:20 drawing shows a line of 210 mm. What is the real length?
2. What should the diagonals of a true rectangle be like?
3. How many hinges does a 2000 mm door usually have?
4. Why do you not glue a solid panel tight into a door frame?
5. How long must a push stick be, and when do you use it?
6. Why must you never wear gloves near a rotating cutter?
7. Why is the back of a wardrobe fixed all round?
8. How wide is a drawer box if the opening is 764 mm and each runner needs 13 mm?
9. Who sizes the timbers of a real roof truss, and can a trainee work on a roof?
10. A piece of timber is 50 × 100 × 2400 mm. What is its volume in m³?
11. What is the difference between markup and margin?
12. What is break-even?

Best next reads: your Hub carpenter's own workshop; the free Wikibooks "Woodworking" (partial); the USDA Wood Handbook chapters on moisture and finishing; the UK HSE woodworking pages; a first-aid course from the Ghana Red Cross or St John Ambulance. Ask a registered Takoradi timber yard for current prices and for a receipt that shows the wood's source.

What this module does not cover: a first-aid certificate; a machine operator licence; the design or sizing of roof trusses and structural frames (an engineer's job); electrical wiring (Energy Commission licensed electricians only); glass cutting and glazing; upholstery; Ghana timber price lists, carpenter day rates and CTVET carpentry standards (none found).

Every source used in this manual is listed, with links, in the Teacher Copy.