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Is there a detail for a best practice to install a window into a structural brick home?

matmarcum | Posted in General Questions on

I’m renovating a structural brick home with 3 and 4 wythe exterior walls, and I’m not thrilled with any of the details my subs are pitching and I’m less thrilled with my own as I keep finding more and more flaws the more I think about them.

I’m almost sure that constructing a treated lumber buck is a reasonable step, but should I be treating or coating the brick before the buck?  After the buck?  No treatment at all?  What’s the rain screen?  In any case, I’d be very appreciative of your help.  Thanks, all.


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  1. Expert Member
    Akos | | #1

    With brick, the only thing I've done is brick mold caulked to the brick. If your window guy is good and get really good fit on the window, you can even get away with no brick mold. Always leave some gaps on the caulk on the bottom for drainage of the interior sill.

    If you have a brick sill, replacing it with a stone or capping it with metal is a good idea. On older homes, there is always deterioration underneath brick sills.

    Not sure what you mean by rain screen here. Are you putting siding over the brick?

  2. matmarcum | | #2

    Hey, Akos:

    That's pretty close to the approach we've been taking. Just as an additional precaution for the longevity of the brickmold, we've been using a fluid applied membrane on the brick, then a 2x4, then fluid on the 2x4 buck, then the window, backer rod and caulk or if the windows have nailing fins, we'll fold them out, use stainless nails and then fluid applied all around. The "rain screen," I suppose, really isn't a rain-screen, but more of a precaution against water intrusion on our system.

    The part that I find disconcerting on all of this is that there's an inherent disconnect between the first layer of fluid applied and the brick. Ive gone back to jobs years later and noticed that the fluid applied is no longer connected to the brick, but sort of loose and retaining it's shape, but not actually adhered. No leaks on air or water, but it's a bit unsettling considering the costs and efforts that went into the process in the first place.

    Considering what I see other, really smart and talented, installers doing, I think I'm on the overkill side of the equation, but I'd prefer to confirm than assume.

    Thanks very much for your response, and I'm almost sure that you're more on the correct column than I am, but windows - especially the larger ones with which we are familiar - are always a big point of concern for me.


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