If you test your floor and it is dry, use your 5 inch width without worries. It would only give you trouble if there is moisture releasing up through the floor. If there is, 3 inch wide will do the same. Test and then use what you prefer. Good Luck

Well - I did the calcium test - the results are not good. It came back w/7.75 over 1,000 sq. feet. I will be doing 1,148 sq.feet.

NOW WHAT DO I NEED TO DO?

I gave the builder the number and he says he's never tested on his spec houses and has never had a problem. he doesn't even know Why I tested for moisture..

The flooring company that I am working with said there is a product you can use, it's dri-loc but it is very expensive.

Do I have other options? Who is responsible in correcting the concrete moisture problem?

Bumping up - calling Echo or others that can guide me on hardwood requirements.

I hate to even tell my story, but I don't want anyone to experience what we did:

Used locally-owned flooring store, installed engineered Hickory; glue-down on slab floor.

My GC had gone AWOL on me, so I didn't have him questioning my reasonings for doing a moisture test. Basically, the flooring store owner did it (tent test in about 5-6 diff places) because the guarantee wouldn't be valid if we didn't show we'd tested before gluing down. The testing came out fine, we ordered our floors and moved on to next thing.

Few weeks later, our painter is in the house, notices a large bucket of ... something (sorry, don't remember, but one of those big buckets of something you can actually use like a stool) has been moved, and there's a water ring on the concrete. He's been around construction his whole life, and tells me that to HIM, what he's seeing indicates a moisture problem. And no, we didn't know to install a vapor barrier when pouring the slab.

I tell flooring guy, he reminds me we tested fine, and says as long as we use the sealant/glue recommended by the manufacturer, it will be all the sealant we need even if there is a slight moisture problem in a few random areas. It's a small town, I've known the guy all my life, I know he's on the line if we have a problem just as much as we are, so we proceed w/the glued-down engineered hardwood.

W/in weeks, you can wander around the big open living area and when you feel a little "give" underfoot, drop to your knees and rap knuckles on the wood and get a hollow sound. Dead giveaway that the glue and the floor are pulling away from slab. There are small pockets in several places, but the biggest problem is a large area between my kitchen island and the transitional area into living room.

Cut to weeks of the flooring manufacturer refusing to honor the warranty - they swear we didn't use their product to install (which we did), they claim there has to be a plumbing leak in the slab or a pre-existing moisture problem (which we tested for, and they'd seen the "just fine" results months before.)

Flooring store owner starts blaming AWOL GC, who'd been around pretty consistently during the pouring of slab, the moisture testing, etc. He also acted as our plumber, and checked every way he knew how to see if there was indeed a leak in the slab; he flatly declared there was not.

Bottom line? My hickory floors came up, the flooring store owner and I wound up splitting the costs not covered by manufacturer (I'll look up exactly who it was, if anyone wants to know). It was AWFUL. Watching that beautiful floor get literally ripped up in pieces killed me; we replaced w/16" ceramic tile.

So in my individual case, passing the moisture test didn't mean anything to anyone once it was clear our engineered hardwood was pulling away from the slab. I'm sure it was either a complete fluke, or there was a plumbing leak somewhere, but it left me terribly gunshy. Basically, I won't put down any kind of wood in new build unless we do a sub-floor. (In our area, Oklahoma, soil isn't suited to basements - almost all new builds of any size/cost go with slab foundation.)

Thank you for sharing your horror story. Luckily, I do have a moisture barrier below my slab. I am going to test the floor again.

I spoke with 2 different flooring guys and 1 says you MUST turn on the radiant heat for a few days and acclimate the engineered floor material before install.

The other says - no need, never had a problem!

THe first company is 2K more than the 2nd. They have both been in business for many years. I will feel better when I test again to see if the slab has less water content. I'm in PA so we have rain, snow, freeze, thaw. THe one company also said there is an additonal on top of concrete product that you can put down that is a moisture barrier andit's about 3K extra!

There's another way to put hardwood on a slab. They lay down a plastic barrier and felt, then plywood over that (they power-nail that into the slab). Then they can nail down solid hardwood (rather than engineered) onto the plywood. I was surprised about this when we found this house, but we've been here for three years and it's great. I wouldn't use glue down again after knowing about this.

Having had glue down engineered in another house, and a moisture problem (from an unknown pipe leaking in the wall): Yes you do need to do the moisture test. Yes you should have them put down the more expensive moisture barrier. Yes you should run your radiant heat, and bring your wood into the house to acclimate for something like a week or so (as I recall.) It's worth it in the end!

Best wishes on your project.

The thing with moisture is that moisture readings can change as water table changes, downspout issues, even frost when it is a slab. the frost moves a couple of feet in under the slab, pushing moisture to the center and the moisture begins to rise out of slab. I do not believe this happens with a full basement, but there are hundreds of reasons on what can go wrong. The felt..plywood style is intriguing as it is not done in my area (Central PA)I would love to see detail specs installation guidelines on that. I'll be honest, it seems that about 9 out of 10 moisture test fail. There are more flooring stores winging it than you could ever imagine. Also, Contractors will blame on Flooring store if it fails so when you get right down to it , they would prefer not to see a moisture test. Its just a really really tough subject to say the least. I will say this, Wood or concrete..most people in the wood business who really understands wood, prefer a glue down over any type of installation. I have picked more experts brain than you could ever image and they all finally come around to a glue down preference as it is so permanent.Just some food for thought...