Correct installation is important for the function and life of the elements. The installation should therefore be carried out by professional fitters of windows and external doors.
The instructions in this manual cover some of the main issues – but not every detail – which may be relevant during installation.
Back boards on fully insulated spandrel panels are loosely fitted. After installation the cavity is insulated and a damp membrane fitted. Then the back board is sealed and fixed with nails.
The window is usually placed within the outer leaf construction of the wall. It should be fitted centrally giving uniform gaps between the frame and structure – ideally the gaps should be 10 to 15mm. The window should be installed with the frame plumb both
horizontally and vertically and should be adjusted and fixed to ensure the correct closing position between the frame and sash.
Windows and external doors should always be fixed to the building structure using mechanical fixings such as frame bolts / screws.
If any foaming material is used to fill the gap between the outer frame surface and the structure the element must be fixed first using mechanical fixings.
The sealant work must be carried out in accordance with sealant manufacturers recommendations and current standards.
When filling gaps with insulation (expanding foam) never put in too much so that it bows the frame. After the expanding foam has cured a waterproof sealant should be applied to the outside (see paragraph on sealant types). To make sure you have enough depth
(in accordance with the sealant manufacturers recommendations) you may have to rake back the expanding foam insulation.
There are a wide range of sealing products to choose from for use between frames and outer walls.
The two most common types are:
– Plastic or elastic mastic
– Asphalt saturated plastic foam (Illmod sealing tapes)
Please refer to sealant manufacturers guide lines to ensure correct product and size before applying.
In order to preserve the wood and reduce heating consumption, it is important that the sealant stays intact. The sealant should therefore be inspected at least once a year, and any flaws should be remedied using the same type of sealant as the original. In case
of any major flaws, all the sealing material must be replaced. In such cases, it must be assessed whether a different type of sealant would be more suitable than the existing one.