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Community and Q&A

Window Flashing w/ Siga Products

pico_project | Posted in General Questions on

Our windows went in this week on a 1955 remodel. I finally got out to the house to check them and was initially surprised by all the windows being taped at the bottom. 

After looking into it more there is very little flashing. Only the Mavjest 500 SA cut from the opening and laid on the sill. I would assume some tape would have been used there? There is a photo of a window we are still waiting on. I believe most were installed like this…

These are Pella Lifestyle casement windows.

Should I be worried about leaks? Also, should I have the contractor remove the bottom tape?

From what I’ve seen from Siga documentation they do not tape the bottom. From what I’ve seen from Pella the sill probably should have had a layer of tape on it?

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Replies

  1. Expert Member
    Michael Maines | | #1

    That's called the full barrier method, and as long as the window never leaks it should be fine. It's certainly a very common way to install windows. Some experts say windows always leak, but after being involved in hundreds of renovations, I disagree--maybe 10% at most will leak, from what I've seen. But that's enough for me to take extra steps so if and when the windows do leak, they are less likely to cause major problems.

    1. pico_project | | #2

      So for this install would the adjustment be removing the bottom tape?

      There is a 22" overhang around the whole house. Single story ranch with hipped roof. All windows start about 8" down from the soffit.

      1. Expert Member
        Michael Maines | | #3

        There's no right or wrong answer. With that overhang, if you aren't in a high-wind area there is a good chance you'll be fine. Without a sill pan and either a slope or a backdam (or ideally, both), removing the bottom tape won't gain you anything. If this was my house I would remove and re-do all of the windows, but that's a lot of work.

        I would try to get ahead of the builder, though, on other details--this indicates that they don't keep up on best practices, and they are likely taking shortcuts elsewhere as well.

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