How to insulate a rim joist around pipes and wires
Pipes and wires running along the joist block the work area and make it difficult to seal the space. While caulk and spray foam can fill these gaps, people often hesitate to apply them out of fear that the materials will damage their HVAC lines.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Running utility lines through the floor joists insteadDid this help you?
- 2Cutting foam board insulation into smaller pieces to fit around obstaclesDid this help you?
- 3stuffing the gap with copper wool or steel woolDid this help you?
- 4applying duct seal to block drafts and moistureDid this help you?
- 5using minimal expanding rodent foam after packing the holeDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“However, I am having an issue with pipes and wires that have been run along the joist.”source ↗
“How do I best seal this? I was thinking of using caulk and spray foam but want to make sure that doesn't damage the HVAC lines.”source ↗
Where this came up
People with this problem also raised
- 3How to cover exposed AC and utility lines on a wall
- 2How to run electrical wire through an exterior wall safely
- 7How to find underground utility lines before digging
- 3How to waterproof low voltage wire nuts outside
- 4How to landscape around outdoor HVAC units and electrical wiring
- 2Sanity check my plan to run power outside