Window Gap Building Regs...

[MarkFish]

I've got a window (still under warranty) with a massive gap (about 10mm) all the way round between the window and the brickwork. All that's keeping weather out is glued plastic trim.

I've been told there's a mimumum gap specified (5mm IIRC) but no maximum.

Can someone point me at regs on this?

 

[freddiemercurystwin]

What regs? Told by who?

 

[MarkFish]

What regs? Told by who?

Building regs.

Maybe I should just have asked to be pointed at the building regs for window instalation.

 

[freddiemercurystwin]

I'm not aware of any gap in any of the Regs. Could be in the British standards somewhere though I guess. They're £££s though so not many have access unless you can be bothered to go to you library where you can (or used to be able to) look them up.

Good practice rules really though. Do you mean maximum gap in your first post? The gap should be sealed with foam and then mastic though not a trim. 10mm is big but not huge.

 

[MarkFish]

I'm not aware of any gap in any of the Regs. Good practice rules. Do you mean maximum gap in your first post? The gap should be sealed with mastic though not a trim. 10mm is big but not huge.

Sorry, I've mislead you. I was actually told the Glass & Glazing federation best practice guide suggests a minium gap of 5mm but no maxium gap. Not bulding regs at all.

Right so in short, 10mm is acceptable?

I just need to seal it with mastic, put some trim over it and forget it?

 

[noseall]

In t' olden days there was zero gap as bricks were built right up against the jambs. there would still be the need to seal the abutment with oil based mastic though.

Replacement windows require a certain gap at to allow fitting. 10mm all round is acceptable but lazy on the part of the measurer. Pump silicone well into the gap then put some trims back around.

 

[simonjay]

I've got a window (still under warranty) with a massive gap (about 10mm) all the way round between the window and the brickwork. All that's keeping weather out is glued plastic trim.

I've been told there's a mimumum gap specified (5mm IIRC) but no maximum.

Can someone point me at regs on this?

A few mm gap is required to allow for expansion of the plastic with termperature variations. It there is none the glass could crack, although it is unlikely. The gap should be large enough to get low expansion foam in, so 5mm is probably about right.
A huge gap is due to poor measuring, unless the side of the opening is irregular (say with a stone building).
Simon.

 

[noseall]

A few mm gap is required to allow for expansion of the plastic with termperature variations. It there is none the glass could crack.

Crack?

Even with the huge gap between the glass and the sash/frame.