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Community and Q&A

Integrity Ultrex window install

joenorm | Posted in General Questions on

I have read through the install guide for these windows but there is one detail I am not clear on.

Do the windows get set directly on the sill or should they always be sitting on shims whether the sill is perfectly level or not?


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  1. Expert Member
    Michael Maines | | #1

    Joe, it's always a good idea to use shims of some sort, sometimes called "setting blocks" or "set blocks." Doing so allows for drainage and breaks potential capillary water movement in the event of a leak. There may be exceptions but I'm not aware of any. Nor any requirements to use setting blocks, for that matter--it's just good practice.

  2. GBA Editor
    Brian Pontolilo | | #2

    Hi Joe,

    You likely already know this, but it is also good practice to have a sloped sill. Many builders install a length of beveled siding on top of the rough sill, so that any water that gets in can drain.

  3. joenorm | | #3

    Thanks, I was not sure if placing the window on shims was "best practice" or not. I will do so as suggested.

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