By PETER MUIRURI
Before the advent of colonial rule, constructing houses using brick and mortar was largely unknown. Africans were at home with wattle and daub, straw and reed and all manner of locally available materials.
Communities in many parts of central and Rift Valley have in the past made good use of timber in house construction. Unlike today, forests back then were dense since population was low and tree harvesting posed few environmental risks.
At the coast, mangrove has been used as construction material for centuries since the arrival of the Arabs.
With the current clamour for green architecture, timber homes are making a comeback with various players in the industry spearheading the technology.
Timber offers a number of advantages foremost among these being its natural qualities. Its ability to blend in with the environment has made it a principal mode of construction in the hospitality industry.
According to David Chola, the principal architect with Adroit Architects, timber is among the cleanest and sustainable construction materials. He says all one needs to do is plant trees that can take several years before harvesting.
Advantages
“Unlike cement and quarry stones that have to be excavated with a measure of negative effects to the environment, timber needs little industrial processing before use in construction. Tree planting regulates the atmosphere in contrast to excavated materials that leave gaping holes in the ground that cannot be put to other use,” says Chola.
Another advantage is that many timber by-products can be put to good use in the same house. For example, sawdust can be used for the manufacture of artificial boards such as high and medium density fibreboards or MDF, veneers, laminates, chipboards and particleboards.
These can be shaped to insulate the interior of the house, giving a smooth finish besides creating beautiful carpentry and joinery fittings. Offcuts can be used to create roofing shingles reducing overall construction costs.
Although their use is highly regulated by the government, hard woods produce the best type of timber for constructing a house. For example, the highly valued red ceder is useful in making the main framework and outer skeleton since it contains wood preserving and pest resistance elements.
It has the ability to handle structural stress better than softer woods and makes for good foundation stilts. Such indigenous trees can take up to 100 years to mature hence the strict regulation in their use.
However, if one chooses to use the softer, fast growing woods such as cypress, it would be beneficial to apply a few layers of varnish to keep pests out as well as protect the wood from natural elements.
According to David Karoro, the technical manager at Economic Housing Group, a number of people are opting for timber due to the quick turnaround time. He says with the fast disappearing quarries, more and more people are becoming passionate about the use of timber.
“Unlike a stone house that can take months, or sometimes years to construct, a two-bedroom wooden home will only take a month to erect. It is also easy to dismantle and transfer to another location with a 90 per cent material recovery rate. A stone house can only be demolished,” he says.
He adds that a timber house presents little complications in erection compared to stone houses that have myriads of technicalities that can slow down the entire construction process.
For instance, timber houses are made in what experts call dry construction since no water is used to make foundation, as is the case when building a stone house.
Karoro dispels the notion that timber houses are inferior to stone houses.
“A timber house contains the same finishes as a stone house. The light fixtures and electrical installations are done to the same quality as any other permanent home,” says Karoro.
Such homes can be found even in the up-market areas such as Lavington, Muthaiga and Karen. In such locations, roofing can be done using light roofing tiles to match the serene neighbourhoods. In rural areas, pre-painted roofing sheets are popular while shiny galvanised iron sheets are common in hotter climates to reflect back the heat.
However, timber houses need more safeguards against the elements than any other house. Kaororo says wood is a favourite delicacy for termites “just like chicken is to humans”.
Termites usually reside underground and can cause a lot of damage to the foundation, a fact that only comes to light much later.
To this end, it is important that one treats the wood beforehand, especially any pieces that will be used for the foundation, using environmental-friendly chemicals.
He recommends the use weather-guard paints on the outside that not only protect the building against direct sunlight, water and fungal attacks, but also provide aesthetic beauty to the home.
The overall design can be manipulated to incorporate deep overhanging roofs that shelter timber facades from direct sunrays in the middle of the day while leaving the cooler, deeper sunrays to penetrate the house later in the evening. With such care and maintenance, such homes can have the same lifespan as stone houses.
On the other hand, there are some who associate timber houses with insecurity saying it is much easier for criminals to penetrate them than stone homes.
However, proponents of this type of construction say cases of insecurity can befall anyone regardless of the type of materials used, adding that there have been cases of thugs attacking people in well-guarded, permanent homes.
It would be prudent, however, to safeguard the home against fire by insulating the inside with fire-resistant materials such as fibreglass. One’s insurance premiums may also be higher due to the choice of construction materials.
But the single greatest challenge in timber construction remains the limited availability of wood. With the strict controls in tree harvesting, dealers in wood products currently rely heavily on imports from Asian countries. PG Bison, a leading supplier of wood panels, obtains its wood from the mother company’s plantations in South Africa.
Experts say there is a need for the country to step up the drive to expand forest cover, cautioning that gone are the days when forests appeared to be inexhaustible resources.
“We must educate our people on the need to expand our forests. We shall always have wood products as long as we exist. Wood was used in Biblical times in temple construction. It was the main material used in constructing Noah’s Ark. Wood should be here for future generations,” says Karoro.
He says an increase in forest cover will bring down the cost of constructing timber houses. Currently, a two-bedroom wooden house costs about Sh2 million, a cost that is almost similar to a stone house but with a quick construction timeframe.
