How to Seam Foam-Backed Carpet

Plan the location of the seams before you install any of the foam-backed carpet. Look for areas that have little foot traffic, such as away from doorways or paths, ideally be covered by furniture. Stretch a chalk line across the length of the floor where the seam will be and snap it across the floor to mark the seam location.

Lay the first piece of carpet on the floor, making sure that it rises up along both walls by at least 2 inches. Then fold back the edge that you are seaming by 1 to 2 feet so you have plenty of room to work.

Place the end of a roll of 4-inch wide carpet-seaming tape on the floor centered along the chalk line. Unroll it all the way to the other end of the room and cut off the excess with a utility knife. Unfold the first piece of carpet so that the edge hits the center of the tape.

Measure the length and width of the remaining floor area and cut a second piece of carpet to this measurement with the utility knife, cutting on the foam side of the carpet. Remember to leave 2 inches on the edges that face the walls.

Lay the second piece of carpet on the floor, aligning the seamed edge with the first piece. Make sure that the fiber direction and pattern of the carpet match.

Plug in the cord of a seaming iron and allow it to heat up for one to two minutes. Lift up one edge of the carpet seam and insert the iron under it. Lay the seam back down so that only the slim handle of the iron is visible.

Pull the iron slowly along the entire seam as it melts the glue. Press the other side of the carpet seam down firmly, as the iron moves away from it, to secure it to the melted glue on the underlying tape. Run a seam roller over the seam to further adhere it and push the carpet fibers together.