Planed Untreated

Planed timber can be used outside, provided it is protected from excess moisture. The best way to achieve this is to select pressure-treated planed timber- this timber is stocked by most merchants for external construction. To improve longevity, any cut ends or drilled holes should be treated with an end sealant. Under no circumstances should a timber post be cross-cut and the cut-end inserted into the ground.

Pressure treated wood can be stained or painted. As always, the item to be painted/stained should be dry before applying the timber finish. Many modern wood finishes are formulated to allow timbers to dry out slowly, with moisture being released in a controlled manner. Choice of stain or paint is personal. One popular product is Osmo Country Colour which is like a paint finish. It is a two-layer product that can be recoated painted with no sanding.

It is very difficult to state how long treated timber will last outdoors. There are many variables that will affect the longevity of exterior timber, and not all of them are inherent to the timber. Care of the installation and the quality of timber is important One possible indicator of the longevity is the 15 Year Warranty that several timber processors are now offering. Subject to a number of Terms & Conditions these timber processors are offering a like-for-like a 15yr Warranty on most of their smooth planed products.

Pressure treated timber will ultimately rot, the main culprit usually caused by water damage. While rotting can’t be stopped it can certainly be slowed. Prevention is better than cure, with regular checking of timber recommended. Look for pooled water or damp timbers and follow the source back to find if you have any leaks in the structure. If care is taken then there is no reason why the service life of many timber products can’t be increased further.