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Community and Q&A

Intus installation

vtcaleb | Posted in GBA Pro Help on

I am considering Intus windows for a project happening soon due to their great U-value and high SHGC numbers. One thing I’m hung up on is how to install them with a 3/4″ strapping rainscreen and exterior trim. The supplier said the window is installed at the sheathing layer then the rainscreen and trim are applied over that. That method seems to flash it well at the top but what about the water running down the face of the windows. There are also weep holes that need to stay open on the bottom making sill trim tricky. Anybody have some experience with this type of window install they could share?

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Replies

  1. GBA Editor
    Martin Holladay | | #1

    Caleb,
    As a first step, I urge you to read this article: ‘Innie’ Windows or ‘Outie’ Windows?

    Once you have read the article, I urge you to explore the many links in the article (including the links in the "Related Articles" sidebar). These articles should answer your questions.

  2. jackofalltrades777 | | #2

    Caleb,

    It comes down to this. You are installing European windows and you should use European installation methods. The problems that occur is when you attempt to install European windows using American installation methods. European windows like Intus do NOT have nailing flanges and they are 3 times thicker & heavier than typical dual pane American windows.

    If you go to Europe and see how they install European windows as "innies" within a wide concrete/masonry wall area, you will see how easy it is to do an innie window. Peel & stick tapes like SIGA Fentrim are used and the WRB is pretty simple. The tape adheres to the outside window frame and down the masonry/wood window area. The tape provides the water, air and vapor barriers all in one application.

    Problems arise when you attempt to install a European window using American install methods. Just stick to what the Europeans developed and have used thousands of times and for decades. It works and there is no need to try and fit the square peg (American install) into a circle (European windows).

    There should be no debate with a European triple pane window like Intus on whether it should be installed as an innie or outie. Once again, in Europe they are installed as innie windows. The windows are wide and heavy and should be positioned within the window buck area where they can be supported the best and NOT hanging on the edge of the wall like an outie window. I can hold a 3x5 American single hung window with one hand. Good luck doing that with a 3x5 European triple pane window like Intus. Not only will it take two hands but two people to hold the window in place.

  3. vtcaleb | | #3

    Thank you both for your responses.

    I have read, at length, the articles mentioned and the related material and I understand the installation principles. I was wondering if anyone had actually installed them and then trimmed them out on top of a rainscreen and how they approached the sill trim. The supplier told me the water was supposed to run down behind the siding underneath the window. This doesn't seem wise to me, hence my question. I see exterior jamb extensions with an old fashioned beveled sill in my future but I was hoping for something simpler and less laborious, (i.e. dollar-intensive...)

    Thanks again for all your work

  4. jackofalltrades777 | | #4

    Caleb,

    What are you using for the flashing? (SIGA peel & stick, Tremco, etc??)
    Where are you installing the window within the wall area? (outie or innie?)
    Are you using screws through the frame or brackets?

    Without knowing the above answers one cannot provide a proper answer to your questions...

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