i'm in a first floor condo w/ a concrete slab under me... there is currently wall-to-wall carpet through the whole place except kitchen and bath. friends of mine do remolding for a living and since i helped them w/ a website and some photo work, they are doing the labor for nearly free, w/ me helping...

we are planning on tearing out the carpet and putting in bamboo flooring for a few reasons. its actually less spendy then carpet to replace, better for the enviornment (bamboo is a grass, more like a weed at the rate it grows), looks amazing and ups the resale value of the home, which i plan on selling in 1-2 years anyway.

the problem we've run into is the concrete. i have to pull back a 2' section to see if the padding from the carpet is glued the whole way through, if it is it will be a long day or three of scraping it all. the biggest problem will be laying the bamboo down.. everything i've read suggests two main ways of doing it on a slab, put 3/4" plywood down or use 2x4's as floaters.

the problem w/ both is cost and raising the floor, in the case of the 2x4's it would raise the floor 2 5/8" from where it is now, which is a good amount. enough that all the doors would need to be trimmed in the house.

my friends say they have used a glue method in the past but the 5gal buckets of glue run around $225 retail (ill pay a bit less w/ their contractors discount) and instead of doing the whole place in a day, day and a half, it could take 3-5 days cuz its much slower

anyone put hardwood down on concrete before? what and how did you do it?

I've never put hardwood on concrete, but we did put laminate down on concrete at our old place. It wasn't nearly so involved -- just the normal laminate over foam routine. (Actually, I think we also used some sort of moisture barrier.)

im not as worried about the moisture, this is 34 year old concrete, im sure its dried out by now

we are hoping to go pickup the bamboo in a week or two, then it needs to sit in my house for a week or so to get to temp and relax a bit... then the install - provided the padding and glue comes up easily.

The challenge isn't always the moisture in the concrete from curing, it's from the environment. If a very wet environment, the concrete can wick moisture from the ground around it. You won't have puddles or anything, but it still might get some moisture.

When I get a few other things fixed in my condo, I want to do exactly the same thing: bamboo flooring over concrete slab.

I plan on using a thin foam moisture-barrier underlayment and floating the flooring over that. No glue, as that will inhibit the natural expansion & contraction and you can get buckling or cracking. The problem with either plywood or 2x4 (never heard of that) underlay is squeaking, even if you sandwich it with foam. If I recall, the foam, sound-reducing, moisture-barrier underlayment is only about $0.25/sqft and comes in long rolled up sheets.

Moisture can still seep through, so you definitely want a moisture barrier. At the very least, a paint-on concrete sealant.

My understanding is that hardwood over concrete in commercial buildings is always glued. So it's a very common way to install it. Firring strips or plywood would indeed raise the level of your flooring and may make for an awkward transition into the room.

this site shows how to install the floors on both plywood and 2x4's... nearly the same photos and text is used on more then a dozen sites so im guessing its a CC content

in any event - my friends who will be helping recently did hardwood glued to concrete on a commercial job (high end hair salon) and it looks amazing, so i know its a problem

ill have to double check w/ the moisture barrier, im pretty sure they did use one.

I had bamboo floors put in a year ago, and the professional installers removed the carpet & tile from the area, sanded and prepped the concrete floor underneath, and adhered the bamboo flooring directly on the concrete.

I have noticed that over the past year, the bamboo does scratch pretty easily. Right by the back door where the dogs go in and out is showing wear. I'm putting down rugs and runners in the highest traffic areas for protection, and getting better about trimming claws! However, the scratches don't look bad at all - the floor is taking wear in high-traffic areas and it just looks lived in, not torn up.

i found this site which talks more about gluing

gnashchick - could you take photos, if you don't mind?

did you go w/ vertical or horizontal, natural or stained?

i've read and been told that bamboo is 25% harder then rock hard maple and shouldn't scratch from average use / wear / dogs nails / etc.

Mike,

I know very little about hardwood, but just a comment from a simpleton. Doesn't most flooring have a surface treatment (i.e. varnishes or stains)? Wouldn't it be this surface treatment that scratches? So whether your flooring scratches or not would depend more on the surface treatment, and less on what the underlying material is (bamboo vs. hardwoods), right?

squished

We had hardwood over concrete in our previous house and it worked fine. They just glued it down to the slab. Fortunately, there was (apparently) a sufficient vapor barrier poured into the slab that we didn't have any problems.

correct, somewhat. most wood floors, bamboo included, comes pre-finished. finishing a hardwood floor is not only stinky but messy as all hell. most people go for the prefinished, which is what im doing.

some wood is much softer then others though, so the varnish doens't really matter. think of an m&m, the shell is hard but the chocolate inside is somewhat soft.. pine for example marrs very very easily and a medium sized dog of 50lbs w/ long nails can mark up a floor in one day.

Some hardwoods scratch much easier then others... I have a brazilian cherry in my house and my dog has spent months running around on it with zero scratches.. we had a plate of food fall and shatter and it didn't leave a mark. In my old house, we had fir flooring and it scratched when I looked at it sideways.

I've heard of stronger finishes but I'm pretty sure they are used only for commercial applications, like your shopping malls and what not.