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Who would I get to check for moisture in slab?

Posted by marti8a (My Page) on
Tue, Aug 13, 13 at 9:17

We pulled up the carpet in the bedroom yesterday and there are some hairline cracks in the slab, one is pencil line. There were some hairline cracks in the kitchen and we put down Redguard before tile, after advice here and on the John Bridge forum. We thought we'd do the same in the bedroom before putting down wood.

But I read the installation instructions for the engineered hardwood I picked out and this is what it said:

Subfloors must be clean and free of dirt, curing compounds, sealers, drywall mud, paint, wax, grease, urethane, or other materials that may affect the integrity of the flooring material or adhesives used to install the flooring.
� All subfloors and subfloor systems must be structurally sound and must be installed following their manufacturer's recommendations. Local building codes may only establish minimum requirements of the flooring system and may not provide adequate rigidity and support for proper installation and performance of a hardwood floor. Whenever possible install the planks perpendicular to the floor joists for maximum stability. Our warranties DO NOT cover any problems caused by inadequate substructures or improper installation of said substructures.
� Test wood sub floors and wood flooring for moisture content using a pin-type moisture meter. Take readings of the subfloor � minimum of 20 readings per 1000 sq. ft. and average the results. In most regions, a "dry" subfloor that is ready to work on has a moisture content of 12% or less and the wood should be within 4% of the subfloor moisture content.

There is also enamel paint overspray all around the perimeter of the room from when the house was built, and it looks like they spilled some and spread it out with rollers in a large area completely covering the concrete.

When we put wood in the living room, the installer didn't test the slab until he was here to lay the flooring, and he didn't acclimate the flooring. They also didn't remove the enamel overspray next to the walls and we didn't seem to have a problem there. We did have problems with that flooring because it wasn't acclimated. I know when flooring people come, they have a job to do and want to get it done without delay.

I'd like to avoid problems this time, and want to get any problems addressed before we even order the wood.


Follow-Up Postings:

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RE: Who would I get to check for moisture in slab?

Any flooring supply company can order you a calcium chloride test. $15 or so. Below is a link as to how to do it. Any flooring installer can do this for you if you aren't comfortable doing it yourself. Most flooring installers will have a pin meter, but that's not what satisfies the manufacturer's requirements for moisture testing. Only calcium chloride will do that.

The bigger issue is that if you have moisture issues, as your previous wood installation might suggest, then you've got a much bigger problem to deal with once you find that out for sure. If you are doing this install merely to be able to list the house, this might be a case of use engineered wood, acclimate the wood properly, and install with a moisture resistant polyurethane adhesive.

Any information that you discover with the test has to be addressed AND disclosed to your future buyer. People run from the words "moisture issue". A polyurethane adhesive is usually the prescriptive for the issue unless you have an underground spring under the house. This might be a case of ignorance is bliss come listing time.

Here is a link that might be useful: YouTube Calcium Chloride Testing


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RE: Who would I get to check for moisture in slab?

With the other floor, they did several moisture tests and all came back normal. I think the problem we had there was because the floor installer picked up the wood from a cold warehouse in the winter and brought it to our warm house and installed it immediately. We had a couple of places were the wood expanded and pushed up at the joints. There was also a lot of checking with the floor and online searches for that floor showed a lot of people with the same problem.

After some construction, we had to have about six square feet replaced a few years later and had to order another box or two in addition to one box from the original order. We let it and the remaining box acclimate in the room for a couple of weeks before the installer came and none of that flooring had the checking problem or lifted off the glue.

The Red Guard we put in the kitchen wasn't for moisture though, it was supposed to keep the larger tile from cracking if there was any movement in the area where the hairline crack is, or anywhere else on the floor.

But yes, if we discover a problem, I know we'll have to disclose it. But I don't want to put down a fairly expensive floor if there is a possibility that we can correct or prevent a moisture problem from the crack we found.

I know there are cracks all over slab foundations. I see them in the garage floor and stained floors in local businesses. And I'm probably over-worrying, but I don't want to take a chance.

edited to add: I taped a piece of clear plastic on the floor last night right over the crack and after 14 hours there is no sign of moisture. I thought I'd put another in the the corner which is an outside corner too.

edited again: I just watched your linked video and the installer or manufacturer's rep definitely didn't do that. They used a moisture meter and then taped something to the floor but it was a flat, white square and they didn't leave it for more than an hour.

This post was edited by marti8a on Tue, Aug 13, 13 at 13:40


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RE: Who would I get to check for moisture in slab?

"Who would I get to check for moisture in slab? "

The flooring company is responsible for making sure the floor (and wood) is prepped properly before installation. Once they start putting a floor down, they have taken ownership of it being a sound foundation for an install.

If you are doing a glue down, you need to get all that stuff off the concrete first. You can use grinders and scrapers. No products should be applied to the floor other than the adhesive.

The floor also needs to be flat and level. Two different things.

Use only the very expensive moisture barrier urethane adhesives. Some include other properties like sound barrier, crack resistance, anti-microbial. Would definitely go with a crack resistant one. Apply it to spec! There are technical parameters to comply with for it to work; like the proper trowel, thickness, amount of bonding to the planks, etc.

The plastic test is not sufficient or accurate enough. Have the floor and wood gauged appropriately and within range of each other for the install.

Unfortunately, don't simply trust the professional with these things, as you have already learned the hard way. Understand the specs yourself and somehow make sure they follow them. The latter part of that is the hardest aspect of the project, labor included, lol.

Good luck. It is amazing what a "flooring expert" can screw up. Like the basic fundamentals. They seem to think all these things are unnecessary. This is also why there are battles between the manufacturers and the installer over failing floors. They need to follow the specs, to a T.

This post was edited by snookums2 on Tue, Aug 13, 13 at 14:42


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RE: Who would I get to check for moisture in slab?

You're exactly right snookums and that is why I am so paranoid now. With our original floor, after we had problems, the installer looked at it and said it was a manufacturer problem and brought a rep in. The rep did his little test and took some floor pieces and said it wasn't their problem. Neither would accept responsibility, the installer claimed the installation instructions didn't specify acclimating or moisture content of wood or slab and claimed he had done more than he had to by putting his meter to it. The floor dealer washed his hands of it, and we were stuck with the floor. Other than one hump right in front of a door, the floor looked fine to most people. We knew it wasn't right because we saw it when it was first put down and saw it changing.


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RE: Who would I get to check for moisture in slab?

That is a sad and sorry tale, marti.

"the installer claimed the installation instructions didn't specify acclimating or moisture content of wood or slab and claimed he had done more than he had to by putting his meter to it."

That is so ridiculous!!! Faulty wood product or not. Unbelievable.

I second the paranoia. I'm afraid to have work done on my home anymore. These people are crazy.


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RE: Who would I get to check for moisture in slab?

I am afraid to have a lot of work done too. Being fairly handy ourselves, at least with wood work, we can see when shortcuts are taken there. But with things like flooring, where we have no real experience, I don't know who to trust or what needs to be done to do it right. I just know our last wood floor wasn't done right.

Who normally does the removing of old paint on the floor? We leveled the kitchen floor ourselves after getting bids for leveling before tiling. We rented a big grinder that did the work fairly easily but it was still an enormous mess.

When they did the other wood floor, they leveled with the adhesive as they put the floor down.

This post was edited by marti8a on Tue, Aug 13, 13 at 16:51


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RE: Who would I get to check for moisture in slab?

I don't think you level a floor with adhesive, other than minor imperfections that will fill in. I think I've even read not to. You do have to be aware of compatibility between products so only use what products the manufacturer says you can to level the floor. I talked with tech support for clarification on things.

Prepping a floor is all in the scope of the flooring company, unless you have a GC who will address it. You can always try to get the bulk up yourselves if you are handy, and then have them finish it up and level and flatten it. It's laborious as well as unpleasant, so they won't miss it and would probably charge a lot.

We can only rely on, say, reviews on Angies and asking them lots of questions, making sure certain things are specified in a contract. It's a slippery slope though. It takes a long time to become an expert. We can only learn so much through research on a project. I don't like "telling" them what to do because my knowledge would be inexperienced and incomplete, and they would, of course, shift all responsibility to the customer (like they don't point the finger elsewhere otherwise, lol). We can, however, ask lots of questions and align them with our research to see if they seem to be working within basic industry/product standards. Check for bad reviews.

It seems to be a cr!@ shoot however we try, though, I will say. I would never again hire without lots of positive reviews. Unfortunately, a lot of those are because they were pleasant, on time or things seemed to look alright on the surface. Not technical reviews.


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RE: Who would I get to check for moisture in slab?

We had a similar problem, when we pulled the old floors there was a lot of efflorescence. Even on carpeted areas, you could see the outline of it around any piece of furniture that said directly on the floor and did have legs to allow the moisture to breathe off.

Our floor installer (who did turn out to be a competent pro!) said he might be able to use a highly moisture resistant but more expensive adhesive and be OK but ONLY if the calcium chloride tests came back OK.

The calcium chloride tests require you put the CC under a dome that is tightly glued down to the floor for a prescribed time period. It then has to be picked up, sealed so I doesn't absorb any more water and then weighed on a gram scale to determine how much weight it gained and there fore, how much moisture it absorbed.

They came back borderline (I think 16 and the limit was 15) so he couldn't do the glue down directly on the slab, as is common here.

Did lots of investigating about causes for the moisture and ultimately concluded we live on black clay at the bottom of a hill in a 1980's house with no vapor barrier under the slab. No leaks and nothing to repair, just kind of a live with it type thing.

To install our engineered floor they did the following:

1. Ground down/scraped off all the old adhesive
2. Patched low areas with some kind of concrete patching stuff (you can't use the adhesive). Floors need to be flat, they don't really care about level. Those are not the same thing and our house was neither. It's now flat.
3. Put down a vapor barrier
4. Nailed down a plywood subfloor
5. Used the patching compound to flatten the plywood in areas where there were still minor dippy doo areas
6. Glued down the wood.

Doing the vapor barrier and subfloor added about $3/ft to the install cost which of course did not thrill us but in the long run, seemed to be the only sensible course.

We did debate blowing off the wood completely and going to tile but part of the area had engineered hardwood on it originally and it seemed to have held up OK, so we decided to stay with wood.

We had 1,000 sq/ft of flooring to replace. It took 3 competent guys 3 days to do the initial prep and another 3 days to do the install, so had we tried to do it ourselves we would still have been doing it sometime in the next century I think.

Hope that helps.


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RE: Who would I get to check for moisture in slab?

That helps a LOT, and my thanks lucas. We are also on black gumbo in a house built in the 1980s. The builder was fairly progressive at that time but I don't know if there is vapor barrier under the house.

I did contact the GC sent by our insurance company and he said he does do the calcium chloride test, or can do it. If it comes back as too much moisture, I'm thinking of going with wood look tile.

Edited to add: The floor salesman just called and when I mentioned that there was paint all over the floor (it appears they lined up the doors and sprayed them in one room), he said the self leveling concrete will take care of that.

Any thoughts on that? Will self leveling concrete stick to the paint?

Another edit: Lucas are you in the DFW area? If so, would you shoot me an email and tell me who did your work? Competent and referred sounds good to me right now.

This post was edited by marti8a on Wed, Aug 14, 13 at 12:18


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RE: Who would I get to check for moisture in slab?

What % of the floor is covered with paint? What kind? If there's no more than about 15-20% covered, it might not be a problem for SLC. Or, it might only need to be removed in the high concentration areas. SLC bonds pretty good to just about anything, but if there are large contiguous areas that are covered, that might be a problem long term for that area.

It's not very cost effective to lay down a ply subfloor on concrete. And it takes away ceiling height, which in an older home with only 8' ceilings, can be a problem. The better solution---but not any cheaper-- is to perhaps use a troweled on moisture barrier plus the polyurethane adhesive. If you don't have too elevated moisture though, the polyurethane adhesive is just fine.


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RE: Who would I get to check for moisture in slab?

All around the perimeter there is oil based enamel overspray. Then on one side there is a thick coat the width of a paint roller where one of the kids kicked over a quart of primer and it rolled the length of the room. Rather than clean it up, dh just flattened it out with a paint roller. Also, it looks like something small and square was spray painted in the middle of the room. So all told, only about 5% painted, but that one band is solid, not just splattered.

This post was edited by marti8a on Thu, Aug 15, 13 at 22:15


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RE: Who would I get to check for moisture in slab?

I got a quote for the tests from the GC of the company recommended by our insurance company: $50 per test plus labor. Eeek! I think dh & I can do it. Looks like Home Depot sells the same test as in the video.


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RE: Who would I get to check for moisture in slab?

Thing is, if you do it, they will blame you if there is a problem. Best to let them be responsible for everything, like verifying moisture levels of flooring and wood. They also need to be within range of each other at install. And humidity needs to be within range too.

This post was edited by snookums2 on Fri, Aug 16, 13 at 12:51


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RE: Who would I get to check for moisture in slab?

Being as you have had issues previously and don't want the same sort of problem again I would opt to let them do the test and take the responsibility as snoonkums2 suggests!


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RE: Who would I get to check for moisture in slab?

I think what we're going to do, just for our peace of mind, is to order a set of tests and do them, and not tell the installers if it comes out normal. Then they can run their own test to meet the requirements of the warranty. We suspect that none of the people we've talked to so far have ever done the test.

Edited to add: If the readings say too much moisture, we will tell them.

This post was edited by marti8a on Fri, Aug 16, 13 at 18:03


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RE: Who would I get to check for moisture in slab?

You are correct, a lot of these guys do not bother with these type things. Take a picture of your readings, lol.


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RE: Who would I get to check for moisture in slab?

Good idea. It says on the Taylor website that we can have them read it too.


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RE: Who would I get to check for moisture in slab?

I just got this from the GC:

Also I discussed the paint on concrete issues with the flooring representative. They advised the paint or other products on concrete could be sanded off. The drawback is the dust that will be created and the additional cost for sanding and cleanup. The floor representative recommend, installing the wood over a membrane. The membrane helps absorb noise and no gluing is necessary.

If the wood floor floats on the membrane, does it have the same hollow sound as laminate flooring?


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RE: Who would I get to check for moisture in slab?

Walk on some of those floors first!

As far as the dust, there are machines with dust containment. Not sure how well they work though. I have read with floor refinishing there is very little dust with their dust-control sanding machines, so maybe there is hope. But it is true, the dust is horrendous with those concrete grinders/sanders.


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RE: Who would I get to check for moisture in slab?

I don't know where to go to walk on them. I absolutely HATE floating laminates though.


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RE: Who would I get to check for moisture in slab?

I wouldn't risk it. Since this is a method he likes, I'd ask to arrange to see an install.


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RE: Who would I get to check for moisture in slab?

I went by Lowes today as that is where he said he gets the product. The sales person there didn't know what I was talking about. I don't know if that is because they don't know the products they sell or if that isn't a normal combination.

Then I went to a mega floor store and talked to them about it. They did have engineered installed on a membrane in their store, but said the reason is because they have to take up their floors and install the new stuff all the time and it's much easier than gluing down the wood to the concrete. The guy there said they never install their engineered wood over membrane, but could see how someone would if their foundation moved a lot. Another guy in the store said he has personally installed hundreds of floors on concrete and never used membrane. They both thought the GC was recommending this to pad the bill. I have no idea. I emailed the GC back and asked if he was talking about engineered or laminate.

Our calcium chloride test came in today too. Maybe we can get that started tomorrow.

Edited to add: The GC emailed back and said he uses both laminate and engineered over the membrane and none is glued down.

It may be fine, but I don't have a good feeling about it since no one else seems to know anything about it. Is it a big deal to follow the manufacturer installation instructions or should I just let them do it the way they want?

This post was edited by marti8a on Thu, Aug 22, 13 at 17:51


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RE: Who would I get to check for moisture in slab?

Update and big thank you to hollysprings for posting that video link. Snookums, you are right that the flooring company is responsible, but my previous experience is that they probably won't be.

So I ordered the calcium chloride test, the same one as the video, from Home Depot. After watching the video and reading the instructions, I still had a couple of questions so emailed Taylor Tools for clarification. A rep called me first thing the next morning! He answered all my questions and was really nice and helpful.

So I got the results back today and they are 3.443, 3.806, and 3.987. All over 3 which was the limit for the Shaw flooring we picked. The salesman at ProSource said we could use Titebond 771 if the results were over 3. I did an online chat with Shaw today and she said that if we use a moisture barrier adhesive such as Titebond, and the floor fails, then our issue is with that manufacturer. So basically, if the results are over 3 and we glue down, it's not warranted.

The installation instructions also mentioned a floating system, and the rep at ProSource said when they do that, they use a plastic membrane with cork on top of that and then the wood on top of the cork. I told him I wanted to walk on such a floor before deciding if it would work for us because I don't like the hollow sound of laminate flooring.

Are there any other options?


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