Large sections of concrete should have joints running across the full width of the slab, ... Fill the new or existing expansion joints with pre-formed expansion joint strips or foam backer rod.

Cut the backing rod to length and press it into the expansion joint. Press the rod down to about a 1/2-in. to 3/8-in. below the slab surface. This will let a 1/4-in. to 1/2-in. layer of caulk top ...

Spalled concrete joints are the primary problem for a concrete floor. Though the joint is necessary to control cracking, they ...

Concrete joint filler improperly filled over a backer rod. ... This is part 1 of a three-part series on spalled concrete joint repair. Part 2 discusses repair material type selection.