How to fit a window to single 4" Blockwork.

[Brickster]

Hello,

I am currently building a shed, built with 4" solid blocks.

I have bought some aluminium framed windows, one is 1050mm wide, and one is 640mm wide, the gap at the bottom of the frame is 30mm, which I think should sit on the lip of the window sill.

Not having much experience in building, I didnt notice window sill's are normally used with cavity walls, at least from the diagrams I have seen.

I am trying not to over think this, but I was wondering;

A) Should I double block where the windows will be?

B) Is there a sill that works with a single block wall, either made from concrete, wood or pvc (If so, can you point me in the direction of a shop please)

C) Can I fit the window without a sill? and if this is the case, would I fit the windows using shims and expanding foam and mastic in place, of course with a lintel on top.

D) Any other ideas please ?

Thanks in advance.

 

[foxhole]

The sills only need 4” to sit on.

 

[Tigercubrider]

Are you talking about something to shed water outside?

I am not trade but my old building at work was brick with aluminium horizontal sash windows.
From memory the outside area below the window was built with angled bricks so there was a slight recess for the window. The window ledges were bare brick inside, the main parts of the interior walls was concrete block.

My garage (mid 50's) has quarry tiles as the window ledge

 

[Brickster]

Many thanks for both of the replies.

With reference to the sills only needing 4" (100mm) to sit on, I have seen 220mm sills for sale, with a lip off 20mm (perfect for my 30mm window to sit on) but that would mean 120mm protrouding beyond the window opening.

Would this be okay for stability, as its slightly more than half way?

I been looking at every building I pass, and paying close attention to "Homes Under The Hammer" and noticed not all houses have Sills, and that quarry tiles had been used as pointed out, and also as mentioned noticed a brick built house with the said curved window sill bricks, unfortunately my probelm would be trying to source those bricks, and possibly quarry tiles too as I have struggled to find the sills locally.

I have included a photo below of shed.

Thanks again.

 

[Brickster]

Any thoughts on would it in theory be okay just to block the window in place, and use shims, and foam and finally silicone/caulk?

It is my first time to do this and I would to get it right if possible.

 

[diy_fun_uk]

You can get sills in different depths and thicknesses so if 120mm protruding is too much, buy a shallower sill. Here's a site selling a few different sills (just picked at random):

UPVC Window Sill | Eurocell

And if you watch this from 1 minute on it might give you some pointers?

DIY - How to install Double Glazed Windows - YouTube