From solid to soft in just one weekend
Concrete has a lot going for it—it's durable, versatile, and just plain useful. But let's face it, unfinished concrete can be cold, hard, and not too pleasing to the eye. If you're remodeling a room with a concrete floor, laying carpet on top can completely transform the space with softness, warmth, and color. It's possible to do this project as a DIY, but you'll need specialized skills and tools, plus some extensive prep to pull it off. Follow this guide to learn how to install carpet on concrete without the help of a professional.
Before you buy carpet, measure the length and width of your room to determine its square footage. Add 20% to your total to account for installation errors. Bring your measurements and a rough sketch of your room layout to a carpet dealer. They’ll help you choose the right carpeting and underlayment, plus assist you with renting tools you may not own, such as a knee kicker.
You can add additional layers beneath your carpeting for protection on a concrete floor:
A synthetic carpet pad or similar underlayment adds cushion and insulation to make your carpet softer and more forgiving on a hard, cold concrete surface.
A vapor barrier stops moisture from absorbing into your carpet from below, which causes mold. The barrier is typically a thin plastic sheet or dimpled polyethylene pad.
At least 24 hours before installation, unroll and loosely spread your carpet in the room to air out. This will reduce the intensity of chemical fumes during installation.
Concrete is porous and can be penetrated by moisture, especially in basements. A week or more before installation, take the following steps to waterproof your floor, and prepare the surface for carpet:
Run a dehumidifier to remove existing moisture from the room.
Use caulk to seal any windows or exterior doors.
Use a hammer to pull up any nails or screws lodged in the concrete surface.
Fill in any cracks or holes in the surface with a cement-based waterproof filler.
Use a concrete leveling compound and trowel to flatten any low spots in the slab.
Sand and smooth the entire concrete surface.
Thoroughly vacuum and clean your floor with a bleach solution to kill mold or bacteria, then rinse with clean water.
Clear the room of all furniture and décor. Remove any doors from their hinges and store them safely in another location. If you have baseboards that your carpet won't fit underneath, remove them as well. Follow the steps above to prep your concrete surface for the carpet.
Install concrete tack strips around the room’s perimeter, cutting them with tin snips if needed. Position the strips about a half inch from the wall with the tacks angled toward the wall. Using liquid nail glue and galvanized concrete nails, hammer nails into the strips every 6 to 8 inches. Butt the strips against one another all around the room except in doorways.
Lay your vapor barrier film over the concrete, overlapping the seams for full coverage. If you're using a dimpled polyethylene pad, point the dimples down and tape the seams to make one smooth surface.
Lay carpet padding out from wall to wall and use a utility knife to cut it to size. Have the strips butt against each other and duct tape the seams between them. Your padding should lie completely flat with no bulges or bumps. With your floor fully covered, apply underlayment adhesive around the perimeter to hold the carpet padding in place.
Lay out your carpeting and use your utility knife to cut it from the back. It should roughly fit the room with about 6 inches of extra material left at each edge. Be sure to roll out each piece in the same direction for a consistent texture throughout the room.
Starting in a corner, put your carpet in place. Leave 3 to 4 inches of excess up against the wall, then completely cover the floor and tack strips. Line up edges of adjacent sections tightly and place seam tape, adhesive side up, under each. Use a seaming iron to melt the adhesive and join the sections, pressing them down as they cool, then sealing them with a carpet roller.
Starting in the far corner of the room and working along the wall, attach the carpeting to your tack strips with a knee kicker. To do this, place the kicker firmly on the floor a few inches from the wall. Then, hit the flat, cushioned end with your knee to stretch the carpet tight and secure it to the tack strips. Move along the wall and hit the kicker once every foot.
Use your hands to stretch and pull the carpet from the first wall to the opposite wall and hook it onto the tack strip there. Like the first wall, use the knee kicker to pull the carpet into place. Then, stretch and secure the carpet along the remaining walls. Continue until the carpet is smooth and flat.
You can also use a power stretcher for this step, but they are costly to rent and unwieldy enough that inexperienced users risk damaging their carpeting. Only use one if you have prior experience.
With your carpet stretched and secured, you'll be left with excess around the edges. To cut the excess, use a metal straight edge and cut from the back with your utility knife until the remaining carpet fits tightly against the walls. Tuck the edges into the gap between the tack strips and the wall. You'll want the edges fully concealed when the baseboards are in place.
Attach your baseboards, trim, and doors. Cover the edge of your carpeting at any doorway with metal door jambs. Thoroughly vacuum the carpet after installation to remove stray carpet fibers and other debris.
If you have the specialized skills and tools required to install carpeting, doing so on concrete is possible. If not, tools and supplies cost about $800, not including the carpet itself. Carpeting is the main expense at $1 to $20 per square foot, which adds up in large rooms like basements. Compared to the average $1,760 cost of carpet installation by a pro, you won’t save much.
Concrete is an unforgiving surface that needs extensive prep work before installing flooring on top. Mistakes during prep can cause moisture problems that are very costly to repair, especially when factoring in the time commitment and expense of the initial carpet installation. Hire a carpet installer near you to ensure the job is done right and to adhere to your carpet’s warranty.
While you technically can put carpet directly on concrete, the combination of the concrete’s cold hard surface and the warm layer of carpet can create the danger of moisture gathering under the carpeting. To prevent this, it’s best to lay a protective vapor barrier and a layer of high-quality synthetic carpet padding between your carpet and the concrete surface beneath.
The best underlayment for carpet on concrete is a sponge rubber underlayment. This type of carpet padding is durable enough to endure wear and tear on hard concrete yet soft enough to provide comfort underfoot. It also creates insulation from sound and temperature, providing warmth despite the concrete’s cold surface.
You’ll know if your carpet is stretched enough if it lies completely flat and smooth across your floor. If you have ripples, wrinkled areas, or carpet piling up along the baseboards, these are telltale signs that your carpet is not fully stretched. Release the carpet from the tack strip along one wall and use a stretcher or knee kicker to stretch out the carpet before securing it again.
