How to choose the best wood

In looking at timber and how it should be used, I have been fortunate enough to use the notes prepared by David Hofmeyr of West Cape Joinery for a manual he wrote for the public and the joinery industry.

So for the next few months – with the odd break to look at your winter problems – we will look at timber and its uses in depth.

In SA a number of different woods are used to make doors and windows. Credit: www.sxc

Let’s start with doors and windows.

Choice of timber

In SA a number of different woods are used to make doors and windows. The types of wood that can be used for internal joinery are vast, but not so many can be used externally to withstand our aggressive climate.

Some of the better woods for external use are listed below.

All wood swells when it absorbs moisture, and shrinks when it dries. This is particularly the case with meranti.

If the moisture content is above 20 percent, the conditions become conducive to fungal growth – or dry rot. Moisture is easily trapped behind paint and is often only discovered when it is too late.

If the timber is well oiled with a good timber preservative containing a fungicidal additive, meranti joinery can last the life of the building.

Meranti is not recommended for external joinery at the coast.

It costs the same as meranti.

Acajou is an attractive red-brown wood and is denser and more durable than meranti. The grain is typically interlocked, sometimes straight, and is attractive when finished with a natural preservative. It is a good choice when a better wood is required that does not blow the budget.

Although the wood is reported to retain its shape well after seasoning and shows only small movement in use, it can warp when exposed to the sun, and should be used with caution for tall and slender doors or casements.

The wood is very durable. When properly sealed, kiaat has great stability and it undergoes very little change in response to weather changes. It is an excellent wood to use for external joinery in southern Africa at a moderate price.

The wood is strong, durable and exceptionally stable and exhibits negligible movement after manufacture. It is an excellent choice for joinery as well as flooring, and can be used where underfloor heating is installed because of its dimensional stability.

Unfortunately, it is popular in Europe, and this has driven up its cost so that the premium one pays in SA for iroko joinery when compared to meranti is 60 to 80 percent.

It is mid-brown in colour, with a straight and sometimes interlocking grain that finishes to a most attractive lustrous colour with a clear wood preservative. This timber is often substituted for Burmese teak.

Afrormosia is an ideal wood for external joinery for those who are willing to pay the premium in price for a product that will last as long as the building.

If money is no object, then this should be your timber of choice. - Weekend Argus