Basement Finishing, Moisture, and Carpet. What did you guys do?

I know what you're saying about Dri-Core but that is the route I'm taking and I've never had water issues. It iwll also keep the floor warmer which is important in Minnesota.

I didn't start doing anything to my basement for a year or more. Never SAW one bit of moisture. I know it can start/become a problem at anytime though.

I did carpet in the theater over a pad, and I'll be doing ceramic in the rest of basement.

Like others have mentioned, DRI-CORE is a great idea for under carpet in basements.....

I used Delta-Fl as a subfloor material. Similar in concept to dricore, but you have to put plywood over the top of it. It was relatively easy to install. From what I read, it ends up being a little cheaper that dricore per square foot. There are pictures of the installation in my thread, if you are interested.

You should get a good de-humidifier. I don't use mine during the winter months, but in the summer I probably empty my 30 pint once or twice a week, depending on the humidity. I wouldn't be without one. It will also take the musty smell out.

Here's another vote for Dri-Core. I also debated about spending the money to do my whole basement, but now I'm really glad that I did. For one thing, it was much more comfortable to stand on the Dri-Core while building out the basement for 9 months. As previously mentioned, the floor temperature is much better year-round than what you would have if you put the pad/carpet down right on the slab (I'm not too far from you in MN, so I know that this is an important consideration). I think that you lose 3/4" by putting the Dri-Core down. I built my rear seat platform, my stage, and my interior walls right on top of the Dri-Core.

jj

Dri-core has a toll-free help number. I called it to ask questions about something when I was installing my panels. You might want to ask them about this. They were very helpful when I called.

Don't forget to stagger the columns to get a "brick" effect to lock the panels in more securely.

jj

It is my understanding that this is a bad idea. Moisture will just sit under the poly and have no where to go, which leads to mold growth. The idea behind dricore and related products is exactly the opposite--create an airspace for moisture to evaporate into and move to the edges and enter the room. Once in the room the moist air can be handled by the HVAC, dehumidifier, or window.

First I used a product called Radon Seal on the concrete to help seal out the moisture then I installed DRI-CORE. Believe me you will not regret spending the extra $ for DRI-CORE.

One more vote for Dri-Core from up here in Canada. I have used it in a basement office and plan on using it in the theater. The dricore panel itself is 7/8" thick. Add to that the pad and carpet, or pad and laminate etc.

I just finished 750sf in a basement with DriCore and I do not regret it one bit. We have a bone dry basement in the NE area. I considered the SubFlor product also and chose the newer design of DriCore (which has the extruded star shaped plastic bottom. Like others I dumped a piece in a bucket of water and let it sit for days without issues.

I also called the company to ask about nailing through it for a closet that was built. The manufacturer advised against it, so we use pressure treated lumber against the concrete and then cut the DriCore in around all of these boards. That way the DriCore is one "sealed" surface without punctures.

Can anyone verify this? This seems like a sales pitch more than anything that can be viable. I've heard of many people doing this in Wisconsin to keep moisture from absorbing into the carpet pad.

Has anyone else heard that using poly sheeting under your carpet pad and above the concrete is a bad thing?

I have not seen this done before but I have personally had a situation where there was some poly sheeting on the walls in my basement that water did get behind at one point and some time later when I opened up the wall and was doing some work, I saw a huge amount of mold that was growing happily between the poly and the wall. I ended up tearing out the whole thing, scrubbing the wall with bleach and re-building it again. Something to think about. I'd personally not take the chance. You could call the local building inspector department of your city/town and query them on the issue. I have done that from time to time with questions I have.

Poly on concrete is fine, poly behind "walls" (assuming drywall) is a big no-no.

Mold needs food, drywall paper is food, and the polysheet on a wall will hold moisture in and you will have a mold explosion (which is why Tyvek "breaths")...

The only way mold is growing between poly and concrete is if you spread bread crumbs down there first...in fact, that is the only way to lay any kind of wood floor (laminate or real), there MUST be a vapor barrier.

Exactly what I thought! Thanks for the back up. I'm just going with thick poly under my carpet.

NOT a good idea. In my other life outside home theater, I own a mold prevention and remediation company. Trust me, I get calls when people do exactly this...about 6 months down the road as an average. What will happen is that you'll end up with standing water under the carpet...which is never good...particularly since there are always joints in the poly. This water will seep into the pad thru the joints and voila...you have the potential for growth...even with a mold resistant pad (the word being "resistant"). The typical concrete slab has a ton of drywall dust and joint compound on it and I've seen green and black slabs before. You obviously have subsurface water or you wouldn't have had to bother getting the weeping tile installed.

If you have a below grade concrete slab, hydrostatic pressure *will* force water through the concrete so the only proper way to do it is to stop the water from coming in. Apply a penetrating concrete sealer as you originally thought (ala Kryton or WET ConSeal 1000) or if you live in an are with a very high water table, Kryton T1/T2...then put padding/carpet on with no barrier. Yes, you do put a vapor barrier down for hardwood/laminate...but this ASSUMES you have an essentially dry slab (which is why flooring companies spec out moisture levels and professional installers use moisture testing before putting the wood down). Fortunately, neither product is expensive or difficult to apply. If there are any settling cracks that appear, they should be cleaned, pointed and filled with Kryton Plasti-patch. You also want to check the moisture in the joints if you have concrete walls (if you have it...chisel them out and apply Kryton Krystol Plug) and apply sealant (Kryton T1-T2) to the walls. Sounds like overkill? Trust me, it is FAR cheaper to do prevention than remediation...FAR cheaper.

Sound00d - any comment on the drylok product? Also, I have seen some debate about whether to seal walls and floors or just walls (or nothing). The theory being that if you seal the floors too, hydrostatic pressure will build, and crack the foundation. I see it get argued both ways, which leads me to wonder if its a regional climate issue that decides.

In my personal circumstances, basement in Massachusetts. Ground wasn't packed properly, so I have some minor cracking on the floor. French drain and sump pit installed (pumps to be added soon), was planning to drylok (could use one of the other brands) the walls and dricore the floors. House basically sits on a swamp, though it has been dry the 2.5 years it has existed. Some neighbors have been less lucky though. Appreciate any comments.

Not a sales pitch I promise. Just information from what I have read in this forum and other sites. I will say that if poly under carpet is a good idea, I think a lot more people would be doing it and saving money on dricore, delta-fl, plankton and the like.

When I was at Lowes yesterday looking at carpet, I asked the guy there that claimed to be an installer of many years what I should do for carpet in a basement. He mentioned that there was either a carpet or a pad (can't remember now) that had a moisture barrier of some sort built in that he recommends for basements. Does anyone know anything about this, and if it's a good idea or not? It seems like it would keep the moisture down, possibly creating mold as was stated above.

Guy

We used DriCore throughout our basement and do not regret it one bit. It adds insulation from the cold floors and a barrier from moisture.

I hate that funky smell in some basements from mold and mildew. That reeks!!! The DriCore was a little pricey but I believe it will be worth it in the long run. And my nose will be happy too!

Any other thoughts on this?

Here is one more vote for Delta FL. I considered Dricore, Subflor, and System Platon as well. I opted for Delta FL as so many people had good success. I covered 600 sq. ft. in the below/at grade level of my house with Delta FL and then used approx 500 Tapcon screws to screw down 20 sheets of 5/8" Advantech sheathing. Advantech is a water resistent form of OSB w/ a 50yr warranty. I will be stapling down a 3/8" thick Anderson engineered wood floor and then use area rugs.

With my subfloor complete I immediately noticed the warmer floor and the slight give that the Delta FL provides. The floor feels and sounds similar to the 3/4" hardwood I have upstairs.

I would highly recommend one of these subflooring products. It is worth the cost and effort to install. If you have a decent ceiling height to begin with, losing 1" +/- is not noticeable. The hardest thing for me was making all of the cuts to work around my doorways and closets. Ironically the largest room was the easiest.

My floor was already dry and had a black sealer (applied 36 years ago). It was in relatively good condition and was flat within 3/16" over 10 feet. I wanted to take every precaution to protect the wood floor I want to last for decades.

Drylok is a masonry sealer and not designed for concrete. Kryton is a different animal all together and if you have Masonry walls, I'd call them and ask which products they would advise you to use. Put it this way, Drylok is spec'd at being able to withstand a 22 ft head of hydrostatic pressure...Kryton T1/T2 is spec'd at a minimum of a 150 ft head of pressure...big difference. If you have cracks in a concrete wall or floor, you want to use Kryton Baricote and then seal over the slab with T1/T2. This stuff is used to seal the service tunnels at the base of Dams (as in reservoirs), aquariums, tunnels and water treatment plants. I believe it will work on most homes without too much issue.

As for sealing causing cracks...doubtful. Cracks are caused by three primary things...

Structural settling...which you can't prevent with sealant.

Water getting inside the concrete and freezing...which proper sealing will help to prevent.

Structural weakening of the concrete via leaching out of the minerals that give concrete it's strength...which is what water does. Proper sealing with the Kryton products significantly increases the strength of concrete (they have independent tests that prove this) as well as stops the water. It works chemically with the concrete and the water. The more water that tried to get in, the more sealing that happens and the stronger the concrete gets. It is pretty amazing stuff.

Oh, and no I don't work for the Kryton Group! I do use it in my mold prevention business because it is the best there is.

Thanks for the input Soundood. I'll google up the Kryton stuff and see if its available locally.

I believe my foundation and walls are concrete, but to be honest, I am not positive. Looks like most other basements I have been in.

The advantage of a slow moving project is incorporating all the good advice that comes through here.

Thanks,