Installing Carpet on a Concrete Slab

[powersdov]

I am having carpet installed on the concrete floor of a garage conversion. I don't think moisture is a problem but the concrete floor is always colder than the rest of the house. Should I have the installer put down a vapor barrier before the pad and carpet are installed? Is it is better to have it installed on a 75 degree day or a 45 degree day? I will have both in the coming week. He is also gong to try and nail the tack strips down but may have to glue them down if nailing is unsuccessful. Are there any long term problems/ failures with gluing down the tack strips? I've heard from other people that it would void the warranty on the carpet if the the tack strips are glued down.

[Tom G]

We closed in a porch (concrete slab) and installed carpet. But I was concerned that snow melt could get under the walls or the cold concrete might condense moisture so I had the contractor put down the 2ft by 2ft interlocking wood panels first. These have a plastic moisture barrier with slight projections that keep the wood about a quarter inch off the concrete. I'm pleased with this as it feels as if I'm walking on a regular carpeted sub floor in a house. Floor is much warmer, too. Never did like carpet directly on concrete as that is what we lived with in Arizona (houses on slab construction). Can't remember the name of the panels but we got them at Menard's and I've seen them advertised at other big box stores.

Tom G.

[ransley]

Tape down a 12" piece of clear plastic if water shows under it after a day or 2 you need to water proof it, or get a cheap moisture meter.

[HeyBub]

The concrete will be at the temperature of the ground below it, irrespective of water.

Tack strips should be nailed down. Proper carpet installers use short concrete nails and sooper-dooper guns to shoot the nails. The nails are a bitch to remove.

If faced with that task, it's easier to use an angle grinder and cut them off.

As for a vapor barrier, I suspect that depends most on local conditions. In my town, 90% of the homes (and garages) are on slab foundations and virtually none have vapor barriers.

[norminn]

I disagree, but I've only removed nails in one home. Our carpet strips were in place for about 35 years. When we removed carpet to install tile, it wasn't very difficult to remove them. I'm not muscle-bound and it only required a screw-driver (to start) and a small pry-bar. Some nails pulled out by just moving the pry-bar along the length of the tack strip, but most had to be pried individually. The carpet and pad were very secure until we removed them.

I don't know much about vapor barriers, but would have two concerns: any spills in present garage that might produce fumes in the new room. If the room is kept closed, humidity would be more of a problem without a barrier. Another is pets: if pets urinate indoors, vapor barrier would keep the fluids from soaking into the slab.

[HeyBub]

Same here - one home - but the nails were bastards! I've removed the carpeting, now, in every room and in each case 3/4 of the nails remained after prying up the tack strips. Originally I removed the nails with a pry-bar, but that required some muscle power and chips of concrete came up with the nail. In putting down tile, that required going back and filling the chipped areas with floor leveler (I finally started using sheetrock mud).

For me, the angle grinder was ever so much easier...

[RickH]

Wash it, etch it, then seal it with a concrete waterproofer. Using a vapor barrier after that is ok, but using a vapor barrier alone will cause moisture to condense between the vapor barrier and the top of the slab. Mold will form there. If you use a concrete water sealer the moisture will stay in the slab itself where you want it to stay.

[norminn]

Should I pull up my tile and apply floor leveler? :o) Heck, my nails pulled out with ease - very few broke. A few chipped the concrete, but no more than a dimple - perhaps 1/2" diam. The nails were probably less than 1"; difficult to remember. The tack strip was brittle, and prying it didn't bring along many nails, so had to pry most of the nails separately. Perhaps your nails were longer than mine.

[Oren]

A tip I learned and still use:

Using a framing hammer, tap the side of the tack strip at each nail location. You can use a wooden block, but I just use the hammer. This will loosen the nails (not always) a bit. Then pry off the strip using the claw of the hammer. Leverage any remaining nails; left or right and they pop right out. You may or may not have dimples in the slab, but that's okay.

[Jim Redelfs]

I just had my basement carpeting professionally replaced by a reputable installer.

Most of the old tack strip, nailed down, was reused. That which needed to be replaced was GLUED. Given the coldness of the concrete, we had to wait almost a week while the PL-400 set. I suspect a week wasn't enough because I heard a hammer drill being used. I believe more labor-intensive fasteners were used in some places.

The installer explained that he doesn't nail anymore because the process causes too many pieces of tack strip to split (cheap).

There was no mention of liability or warranty impact. Good luck.