How to choose the timber for your house

Timber is one of the many forest products used for construction world over. It is used in various forms of construction of both small and large buildings. The performance of timber structures and by-products is mainly affected by moisture sensitivity, and how this can be extended by the modification of the natural material, and using effective design details to enhance purpose.

Wood importance

Apart from construction, timber can be put to good use in the making of furniture such as sofa sets, coffee tables, office furniture, sideboards and cupboards among others. However, different types of furniture make use of different types of wood, classified either as hard or soft.

Mr Hillary Muwonge, an architectural engineer in Maya, says using timber in construction not only gives the house a touch of beauty but also strength, especially in roofing of the house.

“Upon completion of the wall of a house, pieces of timber measuring four by two inches wide are put on top of the wall which marks the making of the roof,” he says.

Muwonge advises that roofing should however, be done with timber measuring three by two inches wide, although all timber types have a standard length of 14.

Timber types

Hard wood

Linus Kikomeko, a timber dealer in Ndeeba, says there are different types of hard wood on the market. He points out Mahogany which he says is durable as it neither swells nor shrinks. He explains that this type is mainly used to make wooden furniture such as tables.

The other type is the Walnut which almost has the same strength as Mahogany.

“It resists shrinking and can be used for all kinds of finishing. It is mostly used for furniture, kitchen cabinets and sitting room cabinets,” he says.

Oak is also considered to be hard wood and Mr Kikomeko says apart from being durable, it can easily be bent, resists moisture absorption and is good for furniture and floors.

Maple is the other type of hard wood which is strong and with limited shrinkage. It is best used for floors and furniture. Cherry is also hard wood which resists shrinking. It gets red when exposed to sunlight, and looks better with age; it is used in making cabinets. Rosewood, Teak and Sheesham are the other types of hard wood.

Soft wood

The most common type of softwood is pine, which is easy to use due to its softness, as nails can easily penetrate it. Pine does not shrink, swell or mold and it is mainly used in constructing houses, furniture and moulding.

Hemlock, Spruce and fir, which are other types of soft wood, have a low resistance to decay, but are mainly used for construction of doors, windows, boards, floors and frames.

Redwood and cedar have a natural resistance to decay and are good for making outdoor furniture, fencing and closet lining.

The other forms of wood which are neither in the category of hard or soft wood are plywood, chipboard and MDF boards. Kikomeko says these are mainly used for interior items such as cupboards and shelves.

Purpose for the timber

Before buying timber, there are certain aspects you need to consider such as the intended use.

“If you know that you are buying timber which is meant to be used for the roof of the house, it’s important that the timber is soft such as pine, cider, fir and spruce because these types of wood easily allow nails to penetrate them unlike the hard wood. In case the timber is meant for making furniture, you are free to use any type of wood, either be soft, or hard,” Mr Yunus Ssemambo, a dealer in Ndeeba explains.

According to Ssemambo, whatever the purpose of the timber, it should be well dried because if used when moist, it will start cracking after some time, especially when used in construction and this might lead to collapse of the house roof.

Deborah Buzaare, a timber supplier at Trust in God Quality Timber in Kyengera shares that in case it is used for furniture, wet timber will start molding after some time.

Considerations

According to Buzaare, it is important to ensure that one buys matching timber sizes. She says if the sizes do not add up, it will cause wrong measurements in construction and the architectural design of the building will be distorted.

“There are so many types of timber on the market. It is better to move with an engineer because they not only know the right sizes and lengths of the timber but can also differentiate poor quality timber from the good one,” she advises.

Daniel Bikoto from Biko Furniture Works, opines that when it comes to roofing, they usually advise use of four sizes of timber; four by two (rafters), three by two (purlins), six by two and three by four (inches).

He explains that most of their clients prefer eucalyptus timber in construction majorly because of it is cost-friendly compared to others such as Cypress and Pine

“There are many factors that can be considered to determine good timber from bad and these can range from visual checks to see timber that was badly stored, for example defects on timber that has been eaten by termites and that which is rotten and that can be disqualified immediately,” he says.

According to Bikoto, other factors may include:

● Hardness

Good quality timber should be hard enough to resist deterioration.

● Strength

It should have sufficient strength to resist heavy structural loads.

● Toughness

It should have enough toughness to resist shocks due to vibrations. It should not break in bending and should resist splitting. Timber with narrow annual rings, is generally the strongest.

● Elasticity

It should have the property of elasticity so as to regain its original shape after removal of loads.

● Durability

It should be able to resist attacks of fungi and worms and also atmospheric effects for a longer period of time.

● Defects

Timber should be prepared from the heart of a sound tree and be free from sap, dead knots, shakes and other similar defects.

● Appearance and colour

Freshly cut surfaces should give a sweet smell and present a shining surface. It should have dark colour, as light coloured timbers are generally weak in strength.

● Shape and weight

It should retain its shape during the process of seasoning. Heavy timber is always stronger than light weight timber.

● Workability

It should be well seasoned and easily workable. The teeth of the saw should not get clogged during the process of sawing. It should provide a smoothened surface easily.

Mr Elisa Nkoyoyo Kiwana, an engineer with Stone Roofing Uganda Ltd, shares that one needs to consider the thickness and length of timber before buying.

He explains that thick trees are in most cases mature and buyers should ensure to buy at least two inches thick and 12 inches in length.

He advises that if one wants a good clean job, they should use pine and if they want a strong durable job, they should use eucalyptus timber.

“Let the timber be kept aerated and it should not be packed. The shorter the tree, the weaker it is. It should not have molds or moist that will prompt it to change colour,” he advises.

Nkoyoyo shares that timber from trees such as Muvule, Musambya, Mahogany, Mugavu and the like is too expensive to use for construction and that is why most people opt to use it for carpentry.

“If you are a first time buyer, get a person who is willing to be held responsible for the outcome in case mishaps arise with the purchased timber. Most people are after making a profit but experts will do better selection of the genuine timber to ensure value for money,” he says.

Maintenance tips

Buzaare advises that depending on its use, it is best to treat timber before using it.

 “It’s important to treat timber before using it, especially types such as hemlock, spruce and fir which have a low resistance to decay and the most common type of treatment is the use of used vehicle oil. This prevents the wood from molding and it also keeps away termites.”

Timber’s main limitation of use is the fact that it is prone to rot, insect and water damage but all of these glitches can be minimised or completely avoided by the proper application of a variety of products designed to cover or soak into the wood. Depending on the look you desire, you might choose paint, stain oil or varnish.