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flangeless window install flush with sheathing

Brian_D | Posted in General Questions on

I am planning on installing flangeless windows flush with exterior sheathing and wondering how to detail the sill. If I create a sloped sill with a piece beveled siding or equivalent the window won’t bear fully on the base as the slope is beneath the bottom frame of the window. Is this acceptable practice? I have theĀ  great article detailing the install of flangeless windows as “inbetween” but those rest squarely on the backdam with the slope sill outward on the window.


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  1. Expert Member


    You can use small pieces of the same bevelled siding to make shims for the window to bear on.

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