uPVC window fitting(placement)

[curadh]

Hi all,
Starting my garage conversion tomorrow, window being delivered friday, to sit on a 9" cavity block wall. I am feeling a little jittery as I am fitting it myself. From looking at other windows I can guess it sits behind the concrete sill, on the inner leaf? or does it go over the cavity? Getting the thing plumb and solid shouldnt be a problem but I am just worried about the exact placement.
Appreciate any light shedding.
curadh

 

[kevash]

Hi Curadh

If i am reading your message correctly,you need to sit window back approx 10mm from front of brick work,this allows you get a silicone seal on the outside and a decent overhang for your external sill.

Good Luck
kevash

 

[curadh]

Thanks Kevash, but I'm more confused now!
Ive measured the existing windows, the external sill is 190mm, with around 50mm of that overhanging the blockwork. The window seems to start at the back of this, being around 60mm thick. The internal window board is 150mm and overhangs by 50mm also. Is the window sitting on the cavity?I need the new window to be as deep set as the rest to match up. Does this mean I'll need to close the cavity around the window with bricks so I can set it so deep back?Or is it essential to have a window on the outer skin to keep the heat in as the outer skin is the cold one? I'm sorry for all the questions!!I feel like one of my friends mother!

 

[Glassman]

Here is a useful site I stumbled on a while ago. Its called DIY Doctor.
Follow the link and click on DIY PROJECTS on the side menu bar and then click on UPVC WINDOWS near the bottom of the page.
Quite a handy site for DIY'ers

http://www.diydoctor.org.uk/home.htm

 

[curadh]

wow thats some site glassman, plenty of reading to do!
drilled one of the old walls yesterday, the cavity seems to be 70mm not 50mm. Also took up a window board to have a look at an older one, it seems to be around 60 or 70 thick, and the window sits on the sill at the back of the cavity.This I presume keeps hot air inside from going out and up the cavity.Simple stuff really just took me a while!
Thanks again for all the help.