Window in concrete wall
deerefan
| Posted in General Questions on
I would like to ask for advice on installing finless windows in a concrete wall.
Specifically, what anchors should be used and what is the proper flashing technique? The windows are aluminum, large 8×7 and 12×7.
A local installer states that he drills holes, puts plastic sleeves and then anchors with sheet metal screws. That doesn’t seem to be strong enough, considering wind pressure will probably loosen the screw within the plastic over time. I have not read anything about this technique.
Any help would be greatly appreciated.
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Replies
The way I have done windows in masonry is either by installing wood framing to the masonry than mounting the window to that or by mounting the window directly with masonry screws.
If you will have interior jambs, you can also order your windows with metal mounting brackets. The brackets get screwed to the masonry on the inside making for a quick and very solid window install.
Assuming there is a stone sill on the exterior, usually these get caulked around the perimeter. If you want better results, make sure the installer puts correct sized backer rod before caulking not just go over the spray foam.
If you have other siding over the concrete, you should follow standard innie install details:
https://www.greenbuildingadvisor.com/article/innie-windows-or-outie-windows
Deerefan,
Like Akos, I prefer to mount the window to a wood surround. That lets you case the interior with insulation, and take out any irregularities in the concrete formwork.
Thank you. Our window rough opening is concrete and the aluminum frames need to be anchored directly to this. Can anyone please comment on the type of anchors used for this purpose? Are plastic sleeve anchors acceptable/ desirable? Thank you again.
What do the window manufacturer's installation instructions show for installation in a masonry wall?
In any case, windows that large could see a lot of wind load so I would want to consult with a structural engineer. This isn't a typical situation so typical solutions are not appropriate.