Prepare Joint with Backer Rod

area, here's a piece of backer rod right here. Now, you know, if you get filled it's up with tower tech and it actually, you'll want to both sides, you would expand really well, but if it contracts, it's going to push out a big bolt of caulking, which is what it would look like before, so it's just best to take stuff and some backer rod in there. This will give you a caulking