Improvements in design techniques that minimise water retention and damp penetration, and in microporous paint and stains that allow wood to breath, mean modern, high performance double glazed timber windows need minimal maintenance. Peeling, blistering paint is a thing of the past. Modern finishes also minimise the preparation necessary when it comes to re-painting or staining windows. A soap wash or very light sanding before a single coat of paint or stain is often all that is required.
Factory finished windows do not need painting or re-staining for up to eight years. Thereafter five to eight years staining or painting cycles are the norm. Because it covers parts not traditionally touched by on-site finishing, factory finishing can also increase the life of the frame. While it is true that timber windows need some maintenance, modern high performance windows make that maintenance exceptionally easy.
One of the great benefits of timber windows over other materials is that they can be maintained and repaired.
How long a window frame lasts depends on many factors, so it is difficult to provide accurate figures. However the National Building Federation’s “Standards and Quality In Development” gives PVC-u window frames a life expectancy of 20 years to 25 years, and vacuum treated softwood frames 25 to 35 years. According to the Green Building Digest, “well designed and well maintained timber windows can and do last the lifetime of the building in which they are installed.”
Good design is the key to durability of a window. For example it is important that drained and vented glazing rebates are used to prevent deterioration of the timber and premature failure of the glass sealed units from trapped water.