Materials you'll need:

• Joint tape
• Wallboard sheets
• Cement coated nails
• Joint compound 0 2 x 4s
• Scrap timber lengths
• Joint tape
• Coarse and fine sandpaper
• Corner beads
• Moulding and skirting boards
• Sealer or primer
• Paint

Tools you'll need:

• Measuring toot
• Hammer
• Sharp knife
• Straightedge
• Sawhorse
• Drill
• Sanding block
• Keyhole saw
• Putty knife
• Paintbrush

One way to finish a room is to apply wallboard to the exposed timber studs. A common type of wallboard is gypsum board, a sheet material composed of a gypsum core and a paper outer facing. Some boards are also available with an aluminium foil backing which has additional insulating properties. This also serves as a moisture barrier from the room into the wall space, reducing condensation problems. The sheets are usually sold in two widths: 9.5mm (3/8") and 12.7mm (1/2”) the most common thickness being 12.7mm. The sheets are sold in 1.2m widths (4ft) and in lengths up to 3.6m (12ft). Edges along the length of the boards are recessed so they can be joined with joint cement and tape.

The boards can be fixed to the wall either vertically or horizontally. Normally they are fixed with the long side running from floor to ceiling but they can be placed horizontally if this helps you keep the number of joints to a minimum.

Ideally you should end up with as few joints as possible so plan the placement of the boards with care to use the largest unbroken sheets possible. To work out how much material you will need, calculate the number of square metres in walls and ceiling. This number will tell your supplier how much joint compound, tape and nails you will need to put the board up.

The nails to fix gypsum wallboard should be long enough to penetrate about three quarters the way into the wood stud or joist. They should be cement coated flat-headed nails.

To cut wallboard, score along the board with a knife and straightedge, just cutting into the face paper. Place the board over a sawhorse or length of timber and press evenly on either side of the score line. The gypsum core will snap along this line. Turn the panel over and cut the paper on either side, smoothing the rough edges with coarse sandpaper.

Follow the steps below to line a room with gypsum board:
Step 1.
Make a pair of ceiling braces from 2 x 4s, about 2cm longer than the distance from floor to ceiling. Nail cross boards about a metre long across the top of the 2 x 4s to form T-shaped braces.

Step 2.
Using the braces to hold each sheet in place while you work, line the ceiling using single widths of board to span the entire width if possible. Starting from the centre of the sheet and working outwards. Nail the sheet to each joint at 180mm intervals. Give each nail an extra blow with the hammer to "dimple" it but do not break the paper surface.

Step 3.
When the ceiling is lined start on the walls. Space the nails at 150mm to 180mm intervals and start nailing 150mm to 180mm down from the ceiling. Butt the wall panels against the ceiling sheets.

Dimple all nails as you work and protect any outside corners with metal corner bead strips from the wallboard supplier.

Step 4.
Provide access for electrical out lets, switches etc: by making holes in the wallboard. Draw a pattern of the hole to be cut and cut around the lone using keyhole saw.

When all surfaces have been lined with wallboard, the sheets must be "taped and bedded- using lengths of sealing tape and joint compound. The channels between the boards should be filled evenly and completely with joint cement. Mix the cement as directed by the manufacturer and spread into the joints using a wide putty knife. Ensure the compound is smoothed down even with the surrounding surface. Place a piece of perforated wallboard tape over the joint, centring it, and embed it firmly into the joint using the wide putty knife. Cement compound, which squeezes out through the perforations in the tape and from under the edges should be smoothed down as you go.

Allow the compound to dry, usually for 24 hours, then apply a thin coat of cement over the top. "Feather it" so it extends out a few centimetres from the edges of the join.

When this coat has dried, apply a third coat of cement, this time feathering it out to 200-250mm either side of the channel. After a further 24 hours, sand the surface smooth and level with the surrounding wallboard surface.

Where the nail heads have been dimpled, these should also be filled with cement. Apply 3 coats, feathering and sanding them in the same way as the joints.

Outside corners that have been edged with beading also require 3 coats of cement, with the last coat extending about 200mm onto the walls on each side. Sand smooth.

Inside corners and the joints where walls and ceiling meet are taped and bedded as follows. Cut the tape to length and fold it in half. Lay a bed of cement as for the other joints then press the folded tape into the cement, feathering it out to at least 50mm each side of the joint. Add a second and third coat, ensuring the last coat extends out to about 2mm on each surface. Sand smooth.

Cracks at floor and ceiling can be covered with decorative mouldings and skirting boards should be attached to finish the floor edge.

Allow the compound to dry completely then allow a further 2 days before sealing or priming the surface and painting.