New uPVC window - ballsed-up fitting

For the only one I've ever fitted B&Q sold 10/20mm filler strips that could be glued/siliconed to the sides and top of the frame as required.

You can get packing track that fits on to the sides of windows, it clicks onto it. It is the refuge of the "Surveyors" that visit to "measure" you for DG.

It costs a couple of quid a length.

Alternatively go to a plastics stockist and look at the variety of cover strips to glue over the gaps. A simple quadrant moulding is usually ok. Remember you need quite a decent gap for expansion and contraction of the frame anyway.

I'd make sure that it is central and well packed, with a suitable material, where the screws are. Fill with foam and cap off with a uPVC moulding or a cement fillet.

Peter

Regards, Jon.

You're kidding! Installers will leave gaps anything up to the width of the cover strip (3" or so) and won't even foam fill it if it can't be seen. What I did was to tape 2 strips of hardboard to the edge of the frame, and pva mortar up to that. Remove the hardboard when dry and mastic the

Likewise, 0.5 inches, although larger than it should be, is fine to pack with foam. Then cover with plastic trims - Wickes also do them. Otherwise speak to your UPVC window supplier for frame extensions.

On a separate note I bought a Wickes UPVC window for a bathroom some months back as they were clearing stock. They had optional fixing lugs which lock into the side frame where the screwhead sits to the inside of the frame and will be covered by the internal render. I thought it was a pretty good idea, certainly saves all the messing about of drilling through the frame and trying to keep the frame plumb.

I agree. Foam will easily fill the gap. And is structurally pretty strong.

The issue is making it look nice afterwards....mortar and plaster after gouging out enough foam to get a decent key.

IMHO, that's fine - about the same as I ended up with. I made up a wood fillet about 1/2 thick and secured it flush with the wall. Then filled with foam. Removed the fillet and replaced with mortar - again using a thin piece of wood to give clearance from the frame. Then filled that small gap with silicone.

Thanks everyone, looks like I'll be breaking out the expanding foam then!

David