Why does timber need seasoning

Timber is seasoned to bring it to a condition ready for its final use. It needs to be at the same moisture content as it will be in its final use so it will not move or bend once in place, and to have sugars in the sap reduced to deter fungal attack. When first cut from a tree, timber is very moist, containing sap sugars and water. It also has areas of tension and compression as a result of stresses during growth, and the difference between the heartwood centre of the trunk and sapwood outer part of the trunk.

Sap sugars can be driven out by using moisture such as steam before the final drying, but this can reduce the strength and elasticity of the timber. As the timber dries it will shrink and this shrinking can occur differentially across the piece causing further stresses. The amount of shrinkage depends on the species of tree, the amount of drying and whether the timber is heartwood or sapwood.

Movement through the piece of timber to release these stresses causes a change in the shape of the piece, known as warping. There are four main types of warping:. Ways to reduce the warping during drying include:. Timber being seasoned is usually stacked with small pieces of timber fillets separating each piece to allow even air flow around them. It can be done slowly and naturally outside, or in a large airy shed, or quickly in a controlled kiln.

Some timber is treated with preservatives prior to seasoning. Timber with a shape critical use, such as doors and flooring, may be brought into the building in which it will be used, and left to sit for some weeks to come to equilibrium with the moisture levels in that building, to allow any final movement before fixing in place.

A mature oak takes a minimum of years to develop and Victory's timbers were seasoned for 14 years prior to build. Structural timbers are those timbers used in the construction of a building that are "load bearing". They are the timbers placed under stress by and that support the weight of the building. PLantation timbers are timbers from planted forests, that is humand planted them Old growth forests are the natural ones. Portland Timbers was created in Nash Timbers was created in I'm assuming by 20' circle you mean 20' diameter.

And I'm assuming only one layer of timbers. The closer to circular you want you'll need to cut the timbers shorter. Merritt Paulson owns the Portland Timbers. Tar is used to protect the timbers from weathering. Portland Timbers Reserves was created in Shiver My Timbers was created on The Shops at Fallen Timbers was created in William H.

Timbers died in Timbers was born in Native timbers are simply timbers that are found locally. Native timber can also be 'second growth' timber, which means that it is sustainable. Shivering Timbers - roller coaster - was created in Battle of Fallen Timbers happened on The Battle of Fallen Timbers was called this because right before the battle, tons of trees fell down because of a windstorm.

The Fallen Timbers took place in Spain and was against the French!! Log in. Building and Carpentry. See Answer. Best Answer. Study guides. Q: Why are timbers seasoned? Write your answer Related questions.

Removal of moisture from timber so as to be in equilibrium with the moisture in surrounding atmospheric condition, where timber is likely to be used is called the seasoning of timber. In other words, seasoning of timber means getting rid of the sap and moisture from it. After seasoning has been done timber is not liable to be decayed. After seasoning, the timber becomes dry , hard , light in weight , less in bulk and resilient. It is the best method of seasoning. In this method, water or moisture is driven out from the timber by a very slow process of evaporation.

The object of seasoning is to ensure regular and uniform drying all throughout the timber. In this method logs are kept immersed in ponds or in running streams with the root ends upstream for three to four weeks. Maximum sap is washed out by this process. The logs should be kept entirely down under water by chaining them. Now after that, these logs are kept under the shed for free air circulation.

This is to be the best method of artificial seasoning, as it has no adverse effect on the appearance and strength of the timber. The time required varies with the nature of timber, usually 15 days to two months. Timber seasoned by this method is rendered hardened, denser and proof against dry rot. But it is a costly method of seasoning timber. In this method, timbers are stacked with one third air space in a chamber.

Therefore timbers are exposed to a moist warm atmosphere. Generally, the chamber is constructed with bricks. This method provides better seasoning results with green timber. This process is also known as hot air seasoning.

It renders timber brittle and bleaches deep coloured timber. In a kiln seasoning, the drying of timber is performed inside an airtight chamber of the oven.

Now the relative humidity is gradually reduced.