regs on casement glazing fitting

[martysmarty]

hi guys

I am due to fit my side window and patio doors (2100 x 2200) in our extension we are building. I am just finishing off on the roof so I am now looking at the windows.

This is all being done with building control so I wanted to ask some fitment advice. I have fitted 5 upvc windows before, using a mix of foam to set the frame, concrete screws for belt and braces and your usual window packers to level and stop the frame bowing where it's mechanically fixed, and the usual toe and heal. Also I sat the glass on special packers inside the frames the allow the water to still run out!

now, as it's a "new" dwelling. I know I need to use cavity closers, but is there any specific requirements to how the window is mechanically fixed? I ask because some people use those metal straps that pick up on the inside blockwork.

also it's being rendered so correct me if I am wrong but, I would benefit from having the frames made wider with a UPVC strip around the outside of the frame, so once it's rendered the window will look "normal" from the outside?

personally id prefer to stick to concrete screws, but I have to ask the question!

 

[Mr Chibs]

I fitted my UPVC casements with those brackets you are talking about, and used masonry/concrete screws to fix said brackets to internal brickwork.

I’m going to be cladding (wood) so had a 25mm ‘knock on’ added to the sides... idea was when cladding window reveals go on, the frame will show to be the correct size.

think 15mm was the smallest thickness I was offered, all the way up to 70mm.
Might depend on your window profile. Others will clarify.

 

[^woody^]

so once it's rendered the window will look "normal" from the outside

And look odd from the inside?

You can fix using brackets or direct through the frame it does not matter as long as you have a fixing.

 

[martysmarty]

Thanks guys. I figured that may be the case.

Woody, why would it look odd from inside? The reveals would be bought in past the knock on strips?

They are 20mm strips. Nothing is rendered or plasterboarded yet

 

[martysmarty]

After speaking to a local renderer who i am interested in giving the rendering job to, he has said the render is about 10mm on fresh block. So i dont think theres a need for the knock on syrips after all. And were on the same page in terms of fixing so i think i am happy!