Wooden Timber Windows, Doors and Stairs
High Quality, Long Life, Bespoke
Long Life & Low Maintenance
As standard we design long life and low maintenance into all of our products. We achieve this by doing the following:
Preservation
The only preservative applied to windows in the past was lead based paint. This proved very successful but is unacceptable now. We are making our windows to last well in excess of 50 years and as organic based preservatives are unlikely to remain stable for that period we have researched the use of boron based preservative and
the results show that
it is the best material currently available and as it is a natural material, less likely to cause environmental damage. See Borax for more information. We are also involved with a joint European project that is looking at high temperature treatment with modified linseed oil. This may result in exciting new methods.
Joint Design
Window joints were traditionally mortice and tenoned. Prior to assembly the end grains and the mortice holes were soaked in lead based primer, assembled and wedged. This method was replaced with glued comb joints which has been a major cause of failure. In 1989 Barnsdale won a substantial DTI Smart Award to look into joint design. We are still researching new methods but have concluded that if a liberal coating of resorcinol formaldehyde is applied to the end grains and the joint, long term performance is extremely good.
Glazing
Failure of double glazed units, glazing beads and joints have been a major problem. Our research has centred on reducing the exposed timber beads and reducing the exposure of the units sealant to moisture. Our internally beaded drained and ventilated system has proved to be very satisfactory.
Coatings
If the coating of a window remains intact a well made timber window will last indefinitely. We have carried out extensive work on the overall design of the window to allow the coating to perform well and on the coatings themselves. As a result of this we saturate the assemblies in primer, apply a mid coat and then a top coat of a different colour. As the coating erodes it will finally expose the mid coat which will indicate recoating is required.
Where possible design external joinery in reveal
Traditionally windows & doors were always set in reveal (& in Scotland still are) This was one of the reasons they had such long life. Extended timber cills have the most exposure and will be the first section to fail.
Always specify End-Grain Sealing
When mortice & tenon joints were used, they were sealed with lead based primer prior to assembly. As these joints are no longer viable it is important to ensure that the unexposed end grains are properly sealed. If they are not the end grain will draw up large volumes of water if even a small crack appears across the joint.
Always specify factory finishing
Factory finished joinery that is dip coated in primer and coated with high build paint will out-last site finished joinery by years. Rain and fog do not affect finishing systems in a factory environment. As an example Barnsdale pre-finished windows are guaranteed for 7 years. They will then only need a thorough wash down and a simple one coat application of paint.