If you've ever filled a large gap with caulk, only to watch it pull away from the edges as it dries, you've experienced one of the primary reasons that backer rod exists. Backer rod does more than ...

Q. There’s a wide ugly gap between my concrete outdoor patio slab and the slab my house is built on. I’m trying to determine whether to caulk the crack or fill it with some cement-based patching ...