Tack strip is a strip of wood (or aluminum) that is fastened to the substrate around a room's perimeter about 3/8 inch away from the wall to install carpet with a stretch-in installation. The minor separation between the tack strip and wall creates a gully into which the carpet edge is tucked. The forward edge of tack strip might be beveled to enhance the gully of the tucking edge.
The tack strip, as indicated by the name, has two to three rows of angled tacks or pins protruding from the surface that are directed toward the perimeter. The embedded tacks or pins grip into the carpet's backing to hold the carpet taut.
Most tack strip is made of 3 to 5 plys of wood. The width of tack strip ranges from 3/4 inch to about 2 inches. (We commonly use a 1-3/4" super-wide commercial strip for wide spaces.) The length is most commonly 48 inches, but may be as much as 60 inches.
Tack strip should be selected according to the intended wall-to-wall installation type. Most tack strip is made with pre-started nails. Tack strip to be anchored into a concrete subfloor includes short, 10- or 12-gauge, pre-started concrete nails. Tack strip to be anchored into a wood subfloor includes longer, pre-started wood nails. Tack strip can also be attached using tack strip adhesive.