OK to spray foam over ceiling fan mount/bracket in attic?
We have 3 ceiling fans on the second floor. We used those brackets that turn into the joists for support and then there’s a box that the electrical and fan mount to. I’ve caulked between the sheetrock and that box, however, I’d like to foam over it. Is that safe and OK to do? I’m going to do the same for the smoke detector boxes.
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Yes.
在泡沫之前，我会在盒子上的孔上放一些箔胶带。胶带的目的是防止喷雾泡沫渗入盒子并在那里膨胀，如果您将孔打开，这种情况将会发生一点。这还不足以填充盒子，但这是一个令人讨厌的盒子，从技术上讲是盒子填充的代码问题。我之所以使用箔胶带，是因为它在泡沫应用过程中可靠地停留，但这并不是唯一可行的胶带。请小心，因为泡沫中的化学物质似乎会导致某种粘合剂释放。
Once you have those holes covered it’s not a problem to apply spray foam over the box and associated wiring. You might want to make sure the fasteners are all right first though since the foam will make it impossible to do anything to them later.
Bill
Hi, Fasteners for what part? I will foil tape the boxes- good idea and some may already be set with the caulking but I'll double check it.
I'm not sure if this matters, but if it does, help me to understand. Looking at the specifications for the two products, Loctite is not recommended for attics/ceilings but Great Stuff is.
https://www.lowes.com/pd/LOCTITE-TITE-FOAM-Multi-Purpose-12-oz-Spray-Foam-Insulation/1000881630
https://www.lowes.com/pd/GREAT-STUFF-SMART-DISPENSER-Gaps-and-Cracks-12-oz-Spray-Foam-Insulation/1000673769
Those boxes with the spanner bracket to go between joists usually have a screw clamp that secures the box to the bracket. Just make sure that’s tight before you apply spray foam. You might also check that the bracket is securely fastened to the joists too. Just think “is there anything I need to do while I can get to it, because once I apply spray foam, everything will be inaccessible”.
Bill
The "specifications" tab on the Lowes page is not really accurate. Both products will work for what you are talking about. I haven't use the version of Great Stuff you link to. The loctite foam I have used has been nice to work with.
The pricing I see from Lowes seems expensive vs. Home depot:https://www.homedepot.com/s/great%2520stuff?NCNI-5