Timber as a building material is timeless and versatile, but to maximise longevity and health, it requires careful ongoing treatment. Moisture is a huge problem for many materials, and timber is particularly vulnerable.
- Timber will expand when exposed to moisture, making doors and windows stick in place and difficult to move
- When the timber dries out, it will warp, resulting in cracks in paint, cracks along the grain, loose hardware
- Long term exposure to water will result in mould setting in to the timber
- Long term exposure will result in timber rotting, which can be seen by shrinkage under the paint, soft and squishy wood
Rotten timber will result in the door/window unit, or length of timber needing to be replaced.
Doors and windows are too often installed with the unseen areas such as the bottom or the top unpainted and untreated, leaving the unit vulnerable to moisture. The unit on the left is an example of untreated timber on the bottom of a painted door. The end grain piece is already showing signs of ageing as it begins to crack. The door on the right has been treated with a single coat of paint, however could do with a couple more coats to ensure it is well protected.
Signs of water damage to the base of a door/window unit include shrinkage, expansion, cracks in timber or paint, warping and softness. These are going to be particularly present around the end grains of the timber, where moisture is sucked up into the timber.
Designers need to specify that all six sides of a door should be painted or treated. Superintendents need to ensure what is being installed on site has been treated properly.