hard wood/bamboo floor install question

[IBCRUSN]

I've been reading through several books, install giudes and the NOFMA install manual for hard wood floors and bamboo and I'm finding something inconsistent. None seem to agree on an under layment/vapor barrier between the OSB/plywood subfloor and product. Some say yes and other don't mention it. Are any of you flooring professionals by trade that can point me in the right direction? Thanks.

 

[archie]

I am speaking from working with wood and some experience putting a little flooring so take this as a non professional advice.
Wood tends to expand when there is moisture. If there is heavy furniture or a place where wood can't expand (ex. no space between a doorway) , it will buckle with water. So keeping excessive moisture away from wood is a must to keep it stable. A vapor barrier is generally reccommended because it keeps it stable, especially in situations like a basement. A vapor barrier between floors without moisture (ex. 2nd and 3rd floor) might not be required because it might be more of a way it could retain the water on the wood rather than it remove it ( Think of it as a bowl).This could protect the ceiling below, but ruin a floor that would be harder to replace or fix.
Underlayment and vapor barriers are sometimes combined or seperated as a product. There is underlayment that does not have vapor barriers. Their function is to stabilize the uneveness of the floor or to avoid squeaks/noise from the new wood rubbing against the old wood.
I have taken scraps of laminate floor wood and left them soak submerged in water and have seen a little expansion. I have also seen installed laminate floor in a hospital room and seen some buckling but not as much as a solid wood floor.
I think some manuals say "yes" to vapor barrier to protect themselves from the lability of product failure and some don't metion it because it might not be neccessary. The thing that is very important is to make sure there is enough space for expansion between the floor and the walls. If you don't you will get a buckle in the floor as the relative humidity increases in the room making the whole floor expand and contract.
Hope this info helps a little.

 

[firetruck41]

I am a DIYer that laid 3/4" thick x 2 1/4" wide, quartersawn oak hardwood floor on my first floor (with crawlspace underneath), I put down 15lb felt over 2"x6" T&G subfloor, then 1/2" plywood (to make it nice and level), then hardwood underlayment (brown paper with a thin asphalt vapor barrier inside it), then the hardwood. I climatized the wood for several months (got busy with other stuff, so it sat in the living room), used a manual nailer and made all the joints extremely tight. I am very happy with how it turned out, no noticeable gaps/cracks or swelling have occurred over ~3 years.

 

[reffug]

If you are asking bamboo specific which I have in my home then I would use no underlayment beneath it unless it was in a basement. Between subfloor and the actual bamboo you should be fine IMO.

 

[IBCRUSN]

Thanks guys, I appreciate the info.

reffug,

How has the bamboo held up and do you still like it?

We're planning on replacing a cheap laminate and a worn out carpet in the living area and hallway to make the new house look nicer and give it a nice feel.

 

[reffug]

Its extremelly impressive stuff.

We still like it alot. They say although I don't know if its true that it is 8-10 times harder than Oak. My GC on my job was so impressed with it that he installed it in his own kitchen shortly after my job.

I think you'll be pleased it has a very unique appearance.

 

[archie]

I think the best way to view the need for a vapor barrier is to think where would water be likely to come from. Is it coming from the top as a spill on the kitchen floor or will it come from the bottom like a leak from basement wall. If it will generally come from the top, it would NOT be good to have a vapor barrier. This way water will just flow down into the subfloor,joist cavities and drywall and dry up before damaging the top of the floor with stagnant water.Since drywall would require alot of water to damage it, a small spill would not be too bad of an occurrence to happen. If it did, it would be easier to replaster/paint drywall than doing a floor. The consequences of having water without having a place to go and dry up will also cause mold concerns. Something to consider when using a vapor barrier anywhere without any airflow/insulation.

 

[Capt. Jim]

If there is a conditioned space beneath the floor assembly no vapor barrier is needed. If there is an unconditioned space beneath the floor assembly, or if it is being installed on a slab on grade, you will need to install a vapor barrier.

A vapor barrier is not designed nor intended as protection against spills or leaks.

 

[rsrai]

x2 what the above poster said. if on concrete slab you need the vapor barrier. If you have crawl space underneath you dont need vapor barrier. If you have moisture under house in the crawl space, you need to address that. It should be dry.

 

[IBCRUSN]

Great info.

The kitchen and living space is on the main floor and the basement is 75% finished and all climate controlled. Not having to put down a vapor barrier makes it just a little easier and quicker to install.

Thanks again.

 

[rsrai]

you can buy combo vapor barrier/ foam rolls or cheap if you need. just as easy.

 

[freeheel720]

install a vapor barrior if the floor is at or below grade..

Don't ask me how I know this.

 

[IBCRUSN]

If the vapor barrier is installed and not needed will it aid in keeping the floor quiet and squeak free in the future?

Additional question...

manual or pneumatic nailer? Keep in mind we're putting down ~550 sqft and time is an issue. I figure pneumatic off eBay and resell it after I use it.

 

[FirstToy]

plywood sub, no vapor barrier, bamboo hardwood floors - it works great. This is Socal, very dry climate.

 

[MoJ]

15lb felt paper over the advantech and that's it. Climatizing it to the room for 48hours before hand is a good idea.

 

[84ToyLady]

We had white oak hardwood floors installed in our living room - we live in Texas and there is no crawl space - it is on top of concrete - we do have the vapor barrier (blue foam looking stuff) it helps with noise too - and we also have plywood under the floor. It is beautiful, not loud and I am not worried one bit about the wood buckling. Just my 2 cents. You could probably call a floor company and speak to them about your concerns.

 

[Radd Cruisers]

Did not read all the answers, but I have only one.


Years ago I took a flooring course, they said mainly to put down the barrier when crawl space dirt floor.

 

[reffug]

Additional question...

manual or pneumatic nailer? Keep in mind we're putting down ~550 sqft and time is an issue. I figure pneumatic off eBay and resell it after I use it.

pneumatic for sure...............