This is a measure of how long the timber will last. Timber durability is measured in accordance with BS EN 350-1 on a scale of 1-5, with 1 being the most durable, 5 being non-durable. As standard, we use Accoya wood which is class 1 durable. It is guaranteed 50 years against rot, giving it a lifespan twice that of upvc. There is a commonly held belief that hardwood is more durable than softwood. Broadly this is true, yet it can be highly misleading. For example Meranti is a commonly used hardwood that has a durability class 4, whereas Douglas Fir which is a common softwood is class 3. Oak, often regarded as the most durable of timbers carries class 2 durability.
Our factory finishing uses specially formulated paints, spray applied in a controlled environment. Because the paint finishing is carried out before the windows are glazed, it reaches all areas that would otherwise be inaccessible once windows are installed. The controlled environment of our spray facility avoids the weather dependency and disruption of brush painting after installation of the windows has taken place. We use the market leading Sikkens microporous exterior paint system covered by a 10 year guarantee. We can finish in any colour or combination of colours.
Timber absorbs or loses moisture from its cell walls in response to the humidity of the air. These changes in moisture content cause a measurable change in the size of the timber. It swells when absorbing moisture, and shrinks when losing moisture, and this cycle is repeated constantly. This property is often misunderstood to be the result of poorly seasoned timber, however the rate of moisture movement depends upon timber species and atmospheric conditions. This obviously causes doors and windows to stick, but it also stresses their joints and paint coatings and is the main reason that paint finishes start to crack. The cracking then allows water to infiltrate which causes timber to swell even more. Accoya wood is the only timber that does not shrink or swell. The result is, windows and paint finishes that last longer and require far less maintenance.
The surface tension exhibited by liquids causes wet paint to pull away from sharp frame edges. This means that the dry paint film is very thin and susceptible here, drastically reducing the lifespan of the finish, and in turn, the lifespan of the windows. To avoid this, we machine a 3mm radius on all the exposed outside edges of our windows. This simple process has far reaching effects.
Double glazed units sit within a glazing rebate, secured in place with a glazing bead. Most windows in this country are still designed with the rebate on the outside, for reasons of tradition. However the joints around the glazing bead present a weak spot as they are impossible to make weatherproof if facing outside. Our windows have the rebate on the inside, so the outside weathering face is seamless and watertight. This also provides better security since intruders cannot gain entry by removing the glazing beads.