I noticed a pretty large 3/8" gap around my vinyl window while scraping paint. I'm not sure if this gap is too big for just caulk, and I'm unsure how to fit a backer rod in there. I've seen some options like foam rope, but I worry it might just get pushed into the cavity of the house. Any tips on how to tackle this?
2 Answers
Just caulk directly into the gap after placing the backer rod in! Check after each application to see if there are any remaining gaps and repeat as needed. Just remember, big globs of caulk won’t work here since they can’t handle expansion. Properly using that backer rod is key for long-lasting results!
First, you definitely want to use a backer rod before caulking. It helps fill the gap so you don’t end up with a lot of caulk just sitting there with no support. If the gap is deep, feel free to add more backer rod or even insulation to keep it stable. If you’re worried about how it will hold, you might consider using a low expansion foam for windows and doors, and then caulk over that once it's set.
Yeah, a backer rod is essential. It keeps the caulk from just pulling away from the gap as it expands and contracts with temperature changes.