Tape or putty pads for air sealing interior wires & penetrations
We are at the air sealing stage in our renovation, and I’m seeing lots of information about how canned spray foam can lose its air seal over time as wood expands and contracts through the years. The idea of trying to caulk around each of the interior wire/plumbing penetrations sounds daunting.
Is using something like Dupont Flex Wrap around all of the interior wire/plumbing penetrations that go up into the second floor or attic a good solution for longevity? What about putty pads?
I’m also trying to find the best solution for exterior outlets and wires on the interior side. Can I use tape or putty pads on the interior side of the home to help air seal these areas?
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Replies
Putty pads can lose adhesion over time too, so I'm not sure they are a for-sure option. I've seen plenty of times where putty pad material is pretty well stuck, but pops off easily because it gets dried out. The same goes for duct seal. I have NOT seen canned foam fail, at least over the ~25 years or so that I've seen it used.
I think you're OK with canned foam, just inject a good blob into the holes. If you're worried, try cutting a caulk tube for a BIG bead, then fill the hole with silicone or polyurethane sealant.
Tape doesn't usually work well for wires because of the shape you have to work with.
Bill
Fill with sealant on top of the foam? Or were you saying instead of the foam?
I would use sealant OR foam, not both.
BTW, I have always used canned foam for all of my wire penetrations, which typically are large(ish) holes with a relatively small wire in them. I've never had a problem, even with some outdoor holes with the foam exposed to sunlight. Sealants (caulk) works better around large pipes that have only small caps between the pipe and whatever the pipe is running through.
Bill
Consider a flexible canned foam, for example: Tremco ExoAir Flex Foam.
The idea behind this being the flexibility will maintain it's adhesion over material differential expansion/contraction,
The differential and bond break is usually mentioned for the reason not to use canned foam. And that's on the assumption that a stiff foam is being used. It's an option now, although I've never seen long term examples.
Regardless, I find foam with a gun gun to be easier to work with around electrical boxes compared to caulk/sealant. And it's way cheaper than putty pads.