Understanding wood and timber

Having some knowledge of wood and its properties will help any DIY carpenters, joiners or roofers.
hardwood conservatory roof

Softwoods are used for general joinery such as joists,rafters, floorboards,joinery, cupboards etc, and is made from a conifer tree (pine, larch, fir or spruce). The wood is usually lighter and softer, easier to work with than hardwood.

Hardwood is made from broad-leaved tree, such as oak, mahogany or teak. The wood is usually denser and harder than softwood.

Manufactured board is made from wood in sheets, strip, shredded or pulped form with resins or glues bonding the pieces or pulp together.

PLYWOOD
plywood flat roofing
Thin layers(‘plys’)of wood are glued together to form aboard which has neither the warping nor splitting tendency of natural wood. This property is due to each layer being laid at right angles to its partner and an odd number of layers being used to make up the finished board. The number of plys varies from 3to 15 – the board thickness ranges from la-1 in. There are many grades: INT for indoor use, WBP (weather- and boil-proof) or EXT for outdoors, aviation for beading, hardwood veneered for high-quality appearance, structural for maximum strength and plank-faced for panelling.

BLOCKBOARD
The inner core consists of strips of softwood glued together. The annual rings of the strips are at right angles to each other and this core is sandwiched between two thin layers of wood – usually birch. ln top-quality blockboard these sheets are faced with decorative hardwood veneers. Board thickness is %-‘l in. and is worked in the same way as ordinary timber. A few words of caution: do not nail or screw too close to the end of the core strips and never paint just one face – treat both faces in the same way. Do not use blockboard outdoors. Laminboard is a version of blockboard in which narrower strips of wood are used for the core.

CHIPBOARD
Small chips of softwood are bound together with a resin adhesive and the sheet is squeezed between rollers to the required thickness. It is cheaper than plywood and blockboardand is widely used as a base for furniture because of its even texture and resistance to warping. For maximum strength buy the multi-layer grade, for painting buy painting quality which has densely-packed small fibres on the face and for underfloor look for the flooring grade. A multitude of faced varieties are available for making furniture and worktops. There are problems. It will bow if the support is inadequate, the cut edge may be ragged, special screws or inserts must be used for fixing and it is not suitable for use outdoors.

MDF
mdf cupboard library
(Medium Density Fibreboard) The base material for fibreboard is made from the fibres produced when timber is subjected to a vacuum in a pressure chamber. These fibres are bonded with resin and then rolled -the pressure used has a profound effect on the quality of the fibreboard. Low pressures produce pinboard which is used for notice boards – high pressure produces panel board for wall lining. Medium density fibreboard is an exciting modern material which although very widely employed in the furniture industry is not often used by the home handyman. Rather similar to chipboard, but with the great advantage that it can be cut cleanly, nailed or screwed without problems and has a surface which can be stained, polished or painted.

HARDBOARD
Pulped wood is mixed with adhesives and rolled into sheets. This Cinderella of the manufactured boards is cheap and has little inherent strength, but has many uses around the home. Standard grade (smooth front face, roughened-mesh backface) is bought for covering doors, floors, drawer bottoms etc. There are perforated boards pierced with round holes (pegboard) or decorative shapes, and there is the tempered grade which has been impregnated with oil to make it water resistant. Enamel- and plastic-tinished boards are used where a decorative effect such as a tile or wood-panelling look is required.

SOFTWOODS

CEDAR WESTERN RED
Reddish-brown with a silky surface. Resists both rot and insects and so is popular outdoors for cladding, fences and
sheds. lt has its problems – colour fades with time, nails work loose and the surface is easily dented.

FIR DOUGLAS
Popular with furniture makers and house builders – very strong and quite cheap, and also knot-free. Sometimes sold
as British Columbian pine – pinkish-brown and even textured but paints badly and cracks outdoors.

HEMLOCK
A general-purpose softwood from Canada and the U.S., used for doors, floors, joists etc. Strong and easily worked
but not good for painting or outdoor use.

LARCH
A British wood, tough and difficult to work. There are 2 important characteristics – it has good rot resistance and
holds nails well. As a result it is used for construction work indoors and fences etc outdoors.

PINE, PARANA
A fine-textured wood, attractively coloured in cream, brown or lilac and otten knot-free. Very strong (used for
staircases) but also temperamental – warps easily, splits outdoors and provides a poor surface for painting.

PINE, PITCH
A wood steeped in history – great halls, church roofs and barn walls are a testimony to its durability. Rich in resin,
highly inflammable, rather difficult to work and even more difficult to find.

REDWOOD
The most popular of all woods for the home carpenter – inexpensive, reliable, easy to work, good for painting, etc.
Colours range from cream to reddish-brown, commercial names include Scots pine, Baltic pine, red deal and ‘pine’ furniture.

WHITEWOOD
Popular and inexpensive like redwood, but there are differences. It is softer with a finer texture, and the cream colour does not darken with age. Whitewood (other names – spruce, white deal) does not absorb preservatives not for use outdoors.

YEW. The softwood that thinks it is a hardwood. Yew is very heavy and close-grained – the colour is orange or brown.
It is a wood used by cabinet makers and craftsmen to produce high quality articles.

HARDWOODS

AFRORMOSIA
A wood from tropical Africa. Close-grained and golden-brown like teak – used as a less expensive substitute in furniture manufacture. Available for the home carpenter in both solid and veneer form.

ASH
A pale-coloured timber with many uses – panelling, flooring etc. The 2 traditional applications are bentwood chairs
and tool handles. The expert carpenters will tell you to avoid boards with brown streaks.

BEECH
A European wood which is often used in the furniture industry for making a stout and durable frame for veneering. The colour is ivory to pale brown and the grain is straight. Not recommended for outdoor use.

CHERRY
A wood with a wavy grain and a distinctive orange sheen – more often seen as a veneer than as solid wood.
A material tor the cabinet maker and craftsman; but American cherry is sometimes used for joinery work.

CHESTNUT,SWEET
Similar to ash but less expensive – used as a substitute for making office furniture. It is also used as a substitute for oak, which it quite closely resembles. No real drawbacks, but dark streaks can be disfiguring.

ELM
Coffins, wheelbarrows and Windsor chairs are traditionally made from this brownish rough-grained timber. European elm is very durable, but now scarce because of the ravages of Dutch elm disease. Japanese elm is less robust.

IROKO
A popular teak substitute – hard-wearing for both indoor and outdoor use at a significantly lower price. You will find its rich brown colour in parquet floors, furniture, garden seats etc. The texture is rather coarse.

JELUTONG
A wood to buy if you wish to try your hand at carving. Very pale, soft, straight-grained and even-textured.
It is also useful for home carpentry – the surface is smooth and it is easily worked.

LIME
Like Jelutong, an excellent wood for carving and turning. The texture is fine and the grain is straight – the yellowish-brown colour has practically no figuring. Not a popular wood – you may have to search to find it.

MAHOGANY
One of the great.woods, now more often used as a veneer than as solid timber. Not all mahoganies are the same. The African type has a rich orange-brown colour and a distinctive figuring – American is more even in appearance, more
expensive and more lustrous.

MERANTI
A mahogany substitute from Malaysia – cheaper, redder and easier to work than real mahogany. It is quite widely
available in sheet and veneer form and as mouldings – so is the closely-related lauan from the Philippines.

OAK
It is not just patriotism – British oak is the strongest, straightest and most durable of all oaks. Its toughness is
legendary, but it is expensive, difficult to work and glue, and splits easily when nailed. European oak is a little softer.Japanese is even lighter and not suitable for outdoors.

OBECHE
Not a quality hardwood – it is a light, easily-worked timber used in the manufacture of whitewood furniture. The grain is open and the colour pale – obeche can be stained and polished.

RAMIN
A very popular hardwood which you will certainly f ind around the house in mouldings, picture frames, furniture etc.
It is a straw-coloured wood, close-textured and easy to nail. A favourite material for the home carpenter.

ROSEWOOD
An expensive wood for the luxury look. The rosewood furniture you see is almost certainly veneered over a cheaper carcasses. Purples and browns swirl under the high lustre finish – you can buy boards as well as veneer but you will find it a difficult wood to work.

SAPELE
A mahogany look-alike – strength and colour are similar but it is less expensive. One drawback – it has a tendency to warp. Sapele is usually bought as a veneer – it polishes well but staining can produce a patchy finish.

TEAK
Teak is widely used in furniture manufacture these days both in solid form and veneer, its rich brown colour marbled
with darker streaks. Apart from its visual appeal it resists rot, water and fire – teak is therefore used for outdoor
furniture, ships’ decks etc.

UTILE
Like sapele,one of the mahogany look-a likes. It has a pink-brown colour and an irregular grain – this wood is easily
worked and is less inclined than sapele to warp. Widely used in the furniture industry.

WALNUT
Best of all is European (especially English)walnut – mid brown with dark streaks and swirling patterns beneath a
lustrous finish. Long associated with antique furniture – today’s walnut table will only be veneered on a cheaper
frame. African walnut is easier to obtain but is less attractive.