# Unlevel floor - exterior door installation



## Windows on Wash (Aug 30, 2011)

Use a stackable shim and support the threshold across the entire span.

After that, you can foam the underside and seal both the exterior and interior so that there is no communication with the garage air. 

Seal all the edges as you don't want garage fumes in the living space at all.


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## Robert95z (Jun 11, 2012)

Windows on Wash said:


> Use a stackable shim and support the threshold across the entire span.
> 
> After that, you can foam the underside and seal both the exterior and interior so that there is no communication with the garage air.
> 
> Seal all the edges as you don't want garage fumes in the living space at all.


Thanks for the reply. Do you have recommendation on what kind of shims I can get at the big box stores?


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## Nealtw (Jun 22, 2017)

Plastic would be best.
https://www.homedepot.ca/en/home/categories/building-materials/lumber-and-composites/shims.html


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## Windows on Wash (Aug 30, 2011)

Use a composite shim that is moisture insensitive. 

https://www.homedepot.com/p/8-in-Composite-Shim-Bundle-of-12-SHM1-12-TW/202807695

Son of a biscuit...should have refreshed the window. 
@Nealtw beat me to it.


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## Robert95z (Jun 11, 2012)

Windows on Wash said:


> Use a composite shim that is moisture insensitive.
> 
> https://www.homedepot.com/p/8-in-Composite-Shim-Bundle-of-12-SHM1-12-TW/202807695


Awesome! They're cheap, and my local store has an abundance of them.

Thanks!


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