Determine how much carpet is needed by measuring the width and length of the room. Add a few inches to both measurements to allow extra carpet for thresholds and doorways. Make a rough drawing of the room and take it to the carpet retail outlet. The sales representative can advise on how much carpet will be needed and can even arrange to have the length cut.
Note: Carpet comes in widths of 12' and 15'. If the room is wider than 15', the carpet will have to be seamed. Some carpet manufacturers require that a professional carpet installer do the job if a seam is required in order to uphold the manufacturer's warranty. These regulations come under the CRI -- Carpet and Rug Institute.
Install tack strip around the entire perimeter of the room, making sure to maintain a 3/8" gulley between the tack strip and the baseboard. A good way to determine that is to place your fingers between the wall and the piece of tack strip. Align the tack strip with the printed arrows pointing toward the wall. When purchasing tack strips, the wider the better. This can be purchased at home improvement centers.
Use a thin strip of plywood to place next to the baseboard and wall to help protect them when hammering the tack strip down.
Nail down tack strip around obstructions like air vents and make sure that every piece of tack strip has at least two nails in it.
Purchase a good quality carpet cushion. It will help protect the carpet and feet.
Cut the protective bag on the carpet cushion down the middle and save both ends to use as garbage bags.
Start in one corner of the room and roll out complete strips of the carpet cushion. Trim as close to the tack strip as possible so there will not be a visible gap once the carpet is installed. Make relief cuts around door frames and other trim. Staple down thoroughly every two feet or so.
Get some help in bringing the carpet roll into the room because it is extremely heavy and you could injure your back. Roll out the carpet and position it in the room in the approximate position in the room, making sure there is plenty of excess along the walls.
To determine if the carpet is square to the room, use a comb or knitting needle on tufted straight carpet, and run a line through the tuft next to the baseboard. Make two vertical cuts and a horizontal cut along the line that has been run through the tuft in the carpet forming a window (Image 1). Repeat these steps on the far end of the wall. If the carpet is not flush to the baseboard, place a knee kicker down (Image 2) and adjust until the carpet is flush to the baseboard.
Start the carpet installation in one corner of the room. If a closet is near the corner, cut a scrap piece of carpet about two inches wide and the length of the doorway. Place a nail every 5" or so and hammer halfway down through the carpet. Place the carpet strip along the doorframe of the closet and hammer the nails into the carpet. This will give a solid surface to power stretch against.
Use nails with a wide head so that removal is easy.
When trimming carpet next to a wall, tack down into the "gulley" (space between the tack strip and the baseboard) using a plastic paddle. Press down firmly with the wooden end of a hammer, firmly seating the carpet into the tack strip. Don't hammer down the carpet into the tack strip as the tacks will bend and fail to hold the carpet securely.
Use the proper power stretcher head for the right carpet -- there is the pinhead that is designed for the cut pile carpet and the cotton head that is designed for the loop pile carpet. The power stretcher usage is mandated by the C.R.I. to avoid losing the manufacturer's warranty. They can be rented at a rental center. Extend the power stretcher across the width of the room and stretch in increments, locking the power stretcher head down and tacking the carpet down into the tack strip.
Replace the shoe molding once the carpet installation is complete and vacuum the entire surface.
Have the carpet professionally cleaned at least once every two years by hot water extraction. Vacuum at least twice a week. For small stains, use a clean white cloth and mild dish detergent solution. Test first in an inconspicuous area (in a closet or behind a sofa). For larger stained areas, consult a carpet cleaning professional.