Could someone clarify something for me...I'm a little confused. There's so much information (and misinformation) out there, I'm not sure what to belive anymore.

I want to install bamboo on a slab. Most sources I have found say that a solid wood should be installed over a plywood subfloor, while an engineered wood can be glued-down directly on the slab (after it's properly prepared.)

However, I found one manufacturer who says their click-together engineered bamboo should not be glued-down, only floated, while another manufacturer says glue-down is fine.

I really don't like the idea of a floating floor...it makes me think of a cheap laminate floor. (Feels like "fake" hardwoods.) But I do like the click-together products, because they make such tight seams, it almost rivals a site-finish. (I can't stand the seams created by the micro-bevels in most pre-finished products. Why do they do that anyway??)

Manufacturer A also says their solid bamboo can be glued down, which is contrary to what I have read elsewhere.

So, basically, I'm getting conflicting information everywhere I turn. Why would one manufacturer say it's OK to glue-down a click-together engineered bamboo, while another says not to? Who's right? Is it really OK to glue-down a solid bamboo to a concrete slab?

Thanks!

Mike,

I glued solid bamboo down to concrete in my last townhome and it seemed to work fine. I only lived there a year and have since moved, so I can't say how the long term reliability was. Bamboo is actually a grass, so I think it reacts a little different that solid or engineered wood.

As a note on bamboo, I would think twice about using it. It's extremely soft, and it scratches and dents very easily. You can dent bamboo with your fingernail. Forget about all these "hardness" ratings and hows it's better than other woods. I would never use it again.

If you have kids or pets, or have a lot of traffic in your house, stay away from bamboo.

This is the first time I've heard this about bamboo. What brand did you use?

Well, you have to be careful what you buy. Not all bamboo is the same. If the manufacturer harvests the bamboo too soon, it will be too soft.

I'm looking at "Strand-Woven" bamboo, which has a Janka hardness of 2800 to 3000 PSI. That's much harder than almost all woods, other than Brazilian Ipe. Natural bamboo may be only 1300 PSI, and carbonized may be only 1050-1150 PSI. I have samples of all of these and none of them will dent with you fingernail.

Still, because I have a dog, if I do bamboo, it will definitely be strand-woven. That stuff is seriously hard!

If you do glue direct to slab I pretty sure you need a moisture cure urathane glue. Go with an engennered if available and of course check the slab's moisture content.

See, that's where I'm stumped. One of the suppliers I am considering says his engineered bamboo should not be glued down, only floated, but his solid bamboo can be glued down.

The supplier said

To me, it does seem logical that an engineered product could have delamination issues when glued down, while a sold product would not.

But KevinD and many others say one should use engineered for glue-down. So who's right?

Engineered hardwood flooring was basically invented to glue down to concrete slabs.

Engineered = gluedown on concrete slab

Solid = nailed down on plywood subfloor

Engineered wood should never de-laminate, unless it was done with cheap glues, and it's a very poor product. Plywood is much stonger than solid wood. Try to break a piece of plywood with 7 or 8 layers vs a solid plank and you'll see what I mean.

The solid wood will trist and warp much quicker and break easier. You can nail wood on a wood subfloor. The wood will expand and contract and give through-out the seasonal changes. That's why you nail solid wood to a plywood subfloor.

But when you glue solid products (not specifically bamboo, but any solid wood, oak, maple, cherry, etc, ) down to concrete, they're is no room for the wood to flex, and it will eventually cup and twist. Wood will always respond to nature and humidity.

Bamboo is a different type of product as a grass, so it's hard to compare bamboo to normal hardwood products.

Strand woven bamboo is a lot harder than regular bamboo, and it won't dent near as near as easy as regular bamboo. From the research I've done, strand woven bamboo contains a lot of glue and will take a lot more abuse than regular bamboo.

Yeah, that's the problem. Most installers seem have a lot of experience with traditional hardwoods, but little to no experience with bamboo. That's why I'm wondering if the typical hardwood conventions may not apply to bamboo.

Also, this engineered bamboo is click-lock...is there any reason why that could affect its ability to be glued-down?

It may be a click lock glueless floating T&G, and the guy didn't really know why it couldn't be gluedown. But who knows, I heard cows fly, too.

It is click-lock, and he does say to float it. (I'm attracted to click-lock because the tight seams rival a site finish. I hate bevels!) Are you saying that no click-lock products should be glued down?

I guess you could glue it if you wanted, but what a pain it the butt!!

Click-loc's are floating floors, for ease of installation. Just like laminates, with click loc, t&g

Major ditto on that!

Well, I hate the feel of a laminate floating floor, the way it gives when you walk on it. Feels "fake" and cheap. Maybe an engineered floating floor wouldn't be so bad. Any opinions on the subject?

What about the several providers who say their solid bamboo can be glued-down? Are they full-of-it, or is it just that bamboo doesn't "play by the same rules" as conventional hardwoods?

All manufacturers are different. When I first started seeing solid 3 ply or vertical bamboo floors back in the mid nineties they were either gluedown or nail/staple down. I can probably think of 20,000 square feet I actually installed before I started this board and the main site.

They were all solid gluedowns. Some manufacturers could be shy of gluedowns because DIY'ers look at the price tag on the proper adhesive that should be used and think.. why use that stuff, let's buy the $60.00 bucket stuff.

Right away, they've bought the wrong adhesive and wonder what the heck happened, or why does my floor look like a washboard? Another thought is rarely will you find installation instructions in any of the cartons of bamboo..or at least those I've handled in the past.

I've had more than one call from dealers across the USA wondering the same thing mentioned above and a few are big names, such as the BIG ORANGE. Most play it down trying to lead me to think they're a confused consumer, but I see the caller ID...DOH..no foolin me!

So, unlike conventional solid hardwoods, it's OK to glue-down a solid bamboo?