Stability of wall when using exterior insulation
Does anyone else wonder about the structural integrity of the finish layer on exterior walls when they’re constructed with exterior rigid insulation?
I’ll assume the builder supports the windows and doors appropriately by tying them into the structural layer. But what about the weight of the finish layers that are well out from the structural wall?
For example, take a wall with 4″ of XPS insulation held to the structural framing/sheathing with 6″ screws. Then layers of other materials for rain proofing etc., and ultimately the finish material like cement board or maybe even stone veneer. So the finish layer could easily be 5″ out from the structural layer of the wall.
There could be a significant bending load on all of the screws, especially a good sized wall with few windows or other openings. Almost like a 5″ thick floating wall, held on by a bunch of screws with a lot of the weight 5″ from the point of structural contact.
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