Commercial-grade carpet almost always requires a glued-down installation. It features a dense, short nap designed to withstand heavy use and is an excellent choice for some home applications, such as over concrete or in a home office or hobby space. If you will be applying carpet glue on concrete, you'll need a special glue that adheres well to high-alkaline concrete floors. Check with the carpet manufacturer to ensure the product you are considering will adhere well to concrete.
For installation, expect to spend about 20 minutes per square yard, not including subfloor preparation. Make sure you're confident measuring, lifting, laying, and cutting carpet.
Seam the carpet in a spot where there will be little foot traffic and so that each piece of carpet is at least 4 feet wide. Align the pieces so that the carpet nap and pattern (if any) will match. Once you have determined the best place for a seam, snap a chalk line on the subfloor where the seam will fall.
Using a carpet knife trim about 1-1/2 inches off the seam edges of the existing carpet pieces (an existing cut edge of the carpet usually results in a visible seam).
On the larger piece of carpet, put a a pen or screwdriver between two rows of tufts about an inch from the seam edge. Drag the pen or screwdriver the entire length of the seam, keeping it between the same two rows of tufts. This creates a visible valley in the carpet.
Using a carpet knife begin the cut in the valley and then use a row cutter to complete the cut. As you cut, angle the row cutter about 5 degrees so that you are cutting away slightly more backing than tufted fiber.
Put the second piece of carpet in place, positioning it so the first piece overlaps it by about 2 inches. The left edge of the piece, as it came off the roll, should be against the right edge of the other piece as it came off the roll.
As you did in Step 3, on the second piece of carpet put a screwdriver or pen between two rows of tufts about an inch from the seam edge. Drag the screwdriver the entire length of the seam. Align the cut edge of the larger carpet piece with this new valley.
Using a carpet knife, begin the cut in the second valley and then use a row cutter to complete the second cut. Check for gaps, sliding the pieces back and forth as necessary to form a perfect seam.
Fold back each piece about 3 feet from the seam line. If necessary weight down the carpet to hold it in place. Vacuum up any loose carpet fibers created during cutting.
Using the trowel recommended by the carpet manufacturer, apply the carpet adhesive recommended by the manufacturer onto the bare floor on each side of the seam. Let the glue set for the proper length of time as directed by the manufacturer.
Unfold the larger piece and adhere it to the subfloor. If you are gluing a large piece of carpet, have helpers hold the ends of the folded back edge taut while you hold the middle. To avoid wrinkles walk slightly ahead of them and work your way toward the edges.
Apply the seam sealer recommended by the manufacturer to the cut edge of the large piece of carpet, squeezing a bead the thickness of the backing onto the actual backing. Take care not to get any of the adhesive on the nap of the carpet.
Working quickly, fold the edge of the short piece of carpet into the adhesive. Work with helpers again, this time keeping the edge of the carpet in a straight line as you approach the seam. Do not apply additional seam sealer to this piece of carpet.
Using a seam roller, press the seam together while rolling along the seam to remove any bubbles and to ensure a firm seal.
Finish laying the large piece of carpet. Roll up the unattached section, apply adhesive to the subfloor, and fold the carpet back into place.
Finish laying the small piece of carpet. Roll up the unattached section, apply adhesive to the subfloor, and fold the carpet back into place.
To ensure a firm seal, roll a floor roller across the entire width and length of the carpet. If any adhesive seeps up from the seam after rolling, you'll need to clean off the glue.
Brush the seam with a clean broom to raise the nap. Trim off stray fibers with duckbill napping shears. Once you have finished the installation, avoid walking on the carpet for at least 24 hours.
Editor's Tip: A high-quality carpet that is properly installed can last for years. To keep your carpet looking good, vacuum it at least once a week.