Some foam-back carpets simply lie on the floor, but most carpets are laid over a separate pad and are stretched and attached to the floor along the perimeter. The key material for this traditional method is the carpet tack strip. Tack strips are lengths of wood, usually Douglas fir, about 4 feet long and 1 inch wide. They are covered with sharp tacks angled at a 60-degree angle. When the tack strips are nailed, screwed, or glued to the subfloor with the tacks angled toward the wall, the tacks will grip the carpet backing and hold the carpet in place as it is installed.
Using tack strips is the standard method for attaching wall-to-wall carpet. The strips both hold the carpet in place, and also keep it stretched and free of wrinkles.
How Tack Strips are Used
In normal installation, the tack strips are installed around the perimeter of the room before the padding is laid down. The procedure usually goes like this:
- The perimeter of room is measured.
- Appropriate lengths of tack strips are cut to length.
- The tack strips are attached around perimeter of room, tack-points-up, so the sharp points are angled outward, toward the walls. On standard floors, the tack strips are nailed to the plywood or MDF subfloor. On concrete slabs, the tack strips are sometimes attached to the floor with masonry nails, or they may be bonded to the slab with construction adhesives. Most tack strips have anchoring nails already attached; those designed for concrete floors have short masonry nails already attached to them.
- The carpet padding sheets are then cut and attached to the subfloor with staples or double-faced tape. The padding sheets are cut and fit so they butt up to the edges of the tack strips. The seams between padding sheets may be secured with tape, depending on the type of padding material used.
- As the carpet is unrolled over the padding and cut to fit, it is stretched out by means of a power stretcher and hooked onto the points of the tack strips. The installation proceeds in a rhythm of stretching, trimming, and hooking the edge of the carpet over the sharp points of the tack strips.
Where to Purchase Tack Strips
Tack strips are available at carpet specialty stores, but are also commonly available even at stores that do not specialize in carpeting installation (i.e., Ace Hardware, Home Depot, Lowe's, etc.). In professional installations, the tack strips and their installation are part of the quoted cost of installing the padding and the carpet.