I'm looking to install bamboo flooring below grade over a concrete sub-floor. Which is the best way to go - glue or float? Thanks for any advice!

Also, in a previous post, I was trying to compare brands. I've decided to go with Shaw, since the company practices environmentally conscious practices, which makes me feel even better about the bamboo decision.

 

Hello Boston,

Have you purchased your bamboo yet? If not, let me know and I can send you a lot of info on "green" bamboo and the best practioners of it.

Did you know that bamboo is NOT recommended for below grade applications? This is because it can potentially mold in the damp environment usually found below grade on concrete. Even though it may seem dry to you, it would be worth doing a test on the concrete to see how much moisture it has as well as a room humidity check.

If you are going to proceed anyways, it is best to glue using a combination of 2 products; a moisture sealer for the concrete and a urethane adhesive to apply the flooring. This way is a little more messy and time consuming than floating but unless you have an engineered floor, floating is not recommended. Some of the better products out there for this type of glue down are Bostiks or Chemque (Fontane). Bostiks has a product called MVP (Moisture Vapor Protection) that is applied with a flat trowel and left for 24 hrs, and then BST (a urethane adhesive) that works well with the MVP. Your first impression might be the expense of these items, but trust me, they work, and work well. I have seen dozens of bamboo installs on concrete with these products and never seen a problem. Other like products will probably do as well, but you should inquire.

Again, the moisture testing of the concrete is critical. Call your local concrete supply store and ask for a Calcium Chloride Test. You will need a small digital scale to use with it, but they should sell them or let you know where to get them. If the water is over 3lbs, than I would consider another flooring option down there.

If you have anymore questions, I will check back regularly or you can e-mail me at jordanpeterson72@gmail.com.

Michael

 

I've seen from a lot of other sources that you can install bamboo below-grade, but not hardwood, which is why we're going with bamboo.

I've heard other people mention Bostiks glue before, also. Thanks for the info!

 

As long as you get it in writing I think you will be fine. I can assure you the majority of bamboo manufacturers will not warranty bamboo flooring below grade.

If you search the internet for some of the larger distributors of the product, not retailers, you will see that below grade is not recommended.

 

I agree with 72

not advisable.

 

The pros can correct me if I'm wrong, but "hardwood" usually refers to any solid wood product. It could be an actual hardwood like oak, or a soft wood like pine or bamboo. So when you hear no hardwood below grade, it probably means no solid wood period.

 

The quote above is generally correct. But I will need to correct the comment that bamboo is a soft wood. The difference in the hardness between oak and bamboo is small enough that it will make no difference whatsoever.

Solid wood products and therefore solid bamboo, are not generally recommended for below grade installation. Because of the real potential for moisture issues. It does not mean you will have problems, but it is common for moisture to be an issue below grade. Generally all wood flooring manufacturers recommend using an engineered product for this application.