Today, most DIY stores and timber merchants can offer large flat boards to suit every need. Manmade boards can be divided into fibreboards, particle boards and laminates. Generally, boards are cheaper than solid wood, and more stable when exposed to heat and moisture changes. However, wood is still ideal for battens and posts because of its strength along the grain. It also has a unique warm appearance for furniture projects.
Timber yards sell standard lengths of wood (ie 1.8, 2.4, 2.7, up to 4.8m for sawn timber) and it is more economic to buy full-lengths, in as long a length as possible. Plan any large joinery project around these sizes.
Wood is commonly sold in nominal sizes – as it started off before planing. The finished size can be as much as 6mm under this, so take a tape measure to the store to check exact sizes if necessary. Ask for kiln-dried (marked KD) timber for furniture projects to reduce the problem of timber movement.
Most timber yards will let you choose the lengths you want from stock. Look out for:
End cracks – these will have to be sawn back to clean the timber.
Cupped or twisted wood. Look down the length of the wood, checking each surface, to spot badly warped wood and reject it.
Dead knots are dark brown or black and will become detached from the timber.
Surface staining, stick marks and insect holes should be avoided for timber that will be seen.
It’s usually cheapest to buy full-size boards (2440 x 1220mm) but larger DIY stores sell 1220 x 610mm and 900 x 600mm sheets for convenience. Standard thicknesses are 4, 6, 9, 12, 15, 18 and 22mm – you can order 3, 25 and even 35mm sheets of some boards. Chipboard for countertops can be up to 50mm. Specialist timber merchants can supply extra large 3050 x 1525mm boards and special finishes.
Do not buy wavy or bent boards as they are difficult to straighten.
When you get the boards home, try to store them upright, preferably clear of the floor. Make sure they lean towards a wall and cannot be accidentally pulled over. Support thin boards with a thicker board at the back so that they don’t warp.
Choosing the right type of board
If you want a painted finish, a board with a dense even texture, such as MDF, gives the best finish. For unseen carcase work, such as kitchen units and flooring, the most economical boards are chipboard and flakeboard.
For garden projects or where moisture may be a problem, choose exterior grade WBP plywood. This type of board is available in thicknesses from 3mm to 30mm. Plywoods need an edging strip to disguise the striped appearance.
This is a specialist and relatively expensive form of plywood which is made up from conventional ply on the outside. However, the inner core is formed from hundreds of thin strips of solid wood glued side to side to form a very strong, stable board. It is good for veneering projects as the edge of the board is unlikely to distort and damage the veneer.
Cheap, multi-purpose boards are often used for drawer bottoms and for the backing of bookcases and cabinets. They are not as rigid as boards made from more plies such as 7-ply marine board.
A plywood made of water-resistant hardwoods sandwiched with a very strong phenolic glue which is not damaged by water, steam, temperature changes or mould damage.
A cheap board composed of large flakes of wood, glued together to form a thick layer of shavings lying parallel with the length of the board. The result is a strong board which is often used for shuttering by builders but may be used for loft flooring and other DIY projects.
Chipboard which is coated with a thin layer of plastic or melamine provides a decorative cleanable surface, used for storage units in the kitchen, bathroom and bedroom. The manufacturers provide edging strip to hide the exposed edges.
One of the most economic boards for the DIYer. However, chipboard is not as strong as plywood and does not hold screws well.
This is produced by chopping up wood shavings into tiny fibres, soaked in water. The mix is then compressed and heated to form a board with a uniform texture. It is sold in thicknesses from 1.5mm to 12mm. It can be used for the backs of cabinets.
Medium-density fibreboard (MDF)
Made up of fine particles bonded together with a resin. The close texture can be planed and shaped with a router. The surface is smooth, making it good for veneering or painting