UPVC windows flexing

[Lawrence]

I have had replacement uPVC windows fitted. They have a dark wood effect. When it is hot the windows 'move away' from the inside wall at the top and bottom corners leaving an approx. 5mm gap which lets draughts come thru. Any filler / sealant put around the inside of the frame cracks and looks unsightly

The windows have been fitted using long heavy duty screws near the corners (side and bottom fixing)

Does anyone have any ideas how to stop the windows flexing?

[stoneyboy]

Lawrence ,
Get the installers back the windows are distorting due to thermal expansion.
end

[Lawrence]

thanks Stoneboy - I will do that. What should be done with the fixing to stop the expansion moving the window?

[welsh brickie]

its best to use a plastic trim on the inside and seal it with a high quality sealant, you cant stop the frame from expanding and contracting the sealant will expand and contract with it

[stoneyboy]

Lawrence,
I doubt that a plastic trim fixed with sealant will accommodate 5mm of movement.
It may be necessary to fit a centre bolt on the flexing side and then use a plastic trim.
end