When applying a floor covering to your sub floor you have quite a large selection of materials to choose from. Terrazzo, vinyl tile, vinyl sheet goods, hardwood, laminate, and carpet; just to name a few. Each has its own installation specifics but let’s take a look at how we accomplish the task of carpet laying over concrete.
The first thing you want to do is take a long look at the concrete surface. The padding and carpet can mask some imperfections, but as long as you are doing it, why not do it right? Any noticeable bumps or lumps should be taken off. This is a simple job with a cold chisel and a hammer. Make sure to wear those safety glasses.
Are there any deep spots or valleys? These you should skim with thinset to bring the concrete surface level. You can apply a second coat if you need to but unless the fault was very bad you should not have to.
While that is setting up you can go to work installing your tack strips. Tack strip is a wooden strip with small metal “teeth” angled out on one side and has small concrete nails partially set into it. The purpose is to grab the carpet where it meets the wall and keep it tight.
The tack strips need to go everywhere the border of your carpet is to anchor it in place. There is no need to get fancy with it; I usually just cut them with a pair of tin snips. Keep them about one quarter of an inch away from the wall (if new construction) or from the existing baseboard (if you are remodeling). Just put them in place and hammer in the cement nails. Do not tap; give them a good whack and drive them home the first time.
Now it is time to install the carpet padding. Roll it out over the entire area to be padded going right up to the edge of the tack strips. Wherever you make seams, connect them with wide, clear plastic tape. If you were going over a plywood sub floor you would staple it down but it is not necessary over concrete.
Now you want to bring your roll of carpet into the room. Roll it out leaving about one half inch over the tack strip you are squaring to and to the end walls. If there is more real estate on the floor surface, roll it out again with the side edges abutting. Also trim it off using the one half inch rule. Where the edges are contacting, use carpet tape and a carpet iron to join the seams. It should appear as if there were no seam at all. If you see a seam, re-do it now.
Ok, now the entire room is covered with carpet – it is time to take care of the borders and make sure we have all the loose spots out of the field. Start in any corner and use a knee kicker to pull the carpet in the direction the wall, and attach it to the tack strip.
Trim off any excess, leaving about 1/2″ to 3/4″ lip of carpet all alongside the walls. Wedge the lip straight down between the tack strip and your baseboard using a putty knife.
Now use a carpet stretcher to tack in the other corners. Go back to the first corner and work your way down the wall with the knee kicker fine tuning every tacked corner.
See Also: How to Make a Carpet Kicker