# Window Sill Question



## OHNOIMONFIRE (Sep 13, 2012)

Hey All,

1st time homeowner here. I've made custom pine window sills for my house and have the casing/moulding cut to length too. That was the easy part.

My house is pretty old, and the window slabs are concrete block and ARE NOT level. Often they are about 1/8 - 1/4" lower than the drywall (see picture). Because they're uneven, putting a piece of thin plywood under the wooden sill is out of the question. 

Any pro tips for ensuring a flat window sill on concrete block? 

Thanks.

-Jeff

M


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## WarnerConstInc. (Nov 25, 2008)

Are there jamb extensions are ready installed?

I assemble the extension jambs and sill and install in one unit. 

You could just use shims to get it level and then shoot some spray foam in there to hold it.


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## OHNOIMONFIRE (Sep 13, 2012)

WarnerConstInc. said:


> Are there jamb extensions are ready installed?
> 
> I assemble the extension jambs and sill and install in one unit.
> 
> You could just use shims to get it level and then shoot some spray foam in there to hold it.


How soon does the foam solidify after its sprayed? Would I be able to level it out?

Also would adhesive stick to the foam?


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## tcleve4911 (Dec 16, 2006)

OHNOIMONFIRE said:


> How soon does the foam solidify after its sprayed? Would I be able to level it out?
> 
> Also would adhesive stick to the foam?


Warner is suggesting that you put the extension jambs and sill together before you fasten it to the window so that it all goes in as a single unit.
Your pieces are cut to specific lengths that create proper reveals and set the sill to the exact location where it's automatically level to the window.
You attach the extension jamb and sill assembly to the window and then spray foam around the entire assembly.


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## WarnerConstInc. (Nov 25, 2008)

Looks like drywall returns.

Just use shims and some adhesive caulk against the window.

You can also nail the apron to the stool, then slide it in with some adhesive caulk against the window.


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## OHNOIMONFIRE (Sep 13, 2012)

Here's on window, finished. This one was actually level.

Thanks for the advice guys, ill try out the shims tonight.


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