When many 1930s-style bay windows are replaced with uPVC the new bay posts in the corners are not designed or installed to support the weight of the building above. The original timber windows were built to transmit the loads down through their frames to the masonry below.
Replacing bay windows
When new uPVC frames are installed it is imperative that the posts in the corners sit on the brickwork below and are a tight fit. The lintel above may also need strengthening if the window originally had mullion posts providing support in the middle.
Retrofitting bay poles
When addressing the problem of an inadequately installed bay window it is often possible to retrofit suitable bay poles to the existing uPVC windows. Whether reusing the existing windows or installing new the process starts by providing temporary support to the building above before removing the windows. The lintel is upgraded if necessary and the sill altered to be able to take new jacking bay poles. With the new bay poles in place the temporary support is removed and the uPVC windows fitted as per the original installation. Finally trims and sealant are used to make it all watertight. The replacement of bay poles is often completed in conjunction with reinforcement of the bay itself and other lateral restraint work.
Please contact us if you have any concerns about your bay poles or any other structural defect. We can sometimes give advice based on a photograph or a telephone call. If it necessary for us to visit your property we can make an appointment that suits you.