We are planning on laying nail down, tongue & groove bamboo. Our house is approx. 10 years old. Main floor and second floor are the osb truss system on 19.2" ctrs. with 5/8" osb flooring. There is a 4' crawl space under main floor. There is a hot water heating grid in crawl space (affixed to underside of trusses). Floor trusses run north/south. Main living room picture window faces south. There are also two windows on the west wall of the living room.

The instructions that came with the flooring said to lay the planks perpendicular to the joists (I am assuming the same would hold true for trusses). However, we were also told that you should lay your flooring so that the seams point at the largest source of natural light.

We removed some of the flooring from the package and placed it in the middle of the room and oriented it in both directions. When placed according to the directions, the seams are highlighted, which is not an issue. When laid so the seams run parallel to the light, it makes the room appear "longer".

Does it really matter if the planking is perpendicular to the joists? The instructions say this is necessary for "structural integrity". Can we lay the flooring oriented to the light?

Thanks for any opinions and help.

Paul

Personally I would want to lay down another layer of plywood. 5/8 OSB over 19.2, is going to be a squeak factory.

Never mind. I'll figure it out.

paull, hold on for a minute . I understand your question about the light source but you got a bigger issue to deal with first.

A single layer 5/8" OSB subfloor is not an approved substrate. Even if it was 16 OC it is still inadequate. You need to add an additional layer of plywood underlayment regardless of which way the bamboo is run.

After adding the underlayment you will still need to cross the trusses or run it a diagonal unless you want to go underneath and install blocking to allow for a parallel install.

Not to hijack but this is a related question... putting an underlayment atop my existing 3/4" floor (500 sf OSB, 1000 sf particle board)

How terrible is it to use OSB instead of plywood? I can get 5/8 OSB for $11 or 1/2" plywood (CDX, not even BC) for $24 at the local big box store.

I know, I know, you get what you pay for... But I could sure use the extra $$ on other things, like paint, drywall, tools, etc....

If I staple down a trial piece then try to remove it - the old "kick test" - will that tell me how well it holds, or does OSB holding power degrade over time more than plywood?

I live in New Mexico where the seasons vary from mostly dry to really dry.

Thanks!!

Explain better what you got in mind Bob. Do you have a 3/4 T&G OSB subfloor with particle board underlayment on top and you want to remove the particle board UL and replace that with plywood?

You may not need to go back with a 5/8 thick unless you are having to match heights somewhere.

Hi Jerry - to clarify: I've got 1000 sf of old construction with 23/32" particle board subfloor and 500 sf of new with 23/32" OSB subfloor, all T&G.

I'll be running parallel to the joists for part of the floor and I don't want to nail into the particle board and I don't particularly want to pull it up... so I figured an underlayment on top of it is the way to go.

No heights to match since this is the whole floor I'm covering at once - so I'm looking at putting the same underlayment on the whole 1500 sf..

I figured 1/2" plywood would be the best thing to do but it's more than twice as much as 5/8" OSB (I figured 5/8" OSB would be needed to match the holding power of the 1/2" plywood).

So I'm wondering if I'm okay with the OSB or if I need to bite the bullet and spend the extra $$ for the plywood?

Bob,

NOFMA has done nail (fasteners) holding abilities on solid lumber, plywood and OSB. The OSB came in last. Oftentimes, the questions should be stated as "should I ?" as opposed to " Can I ?". By that I mean you can do whatever you wish but should you. For myself as a pro for nearly 30 yrs, I'd opt for the 1/2" plywood, based on it's proven record and the recommendations of NOFMA and the NWFA. The 5/8" OSB will work. I just do not know if it would be equivalent to 1/2" plywood or if you will have problems with your install down the road. To keep cost down, keep checking for "deals" on your plywood. Many big box retailers sell plywood at cost and for less than most lumber yards. Also, if you open a charge acct, HD and Lowe's often times give you 10% off your first order. So open an acct., charge the plywood and get the discount, then payoff the acct before any interest accumulates. Just some ideas, FWIW.

I hear you Gary - all good suggestions... I did the HD 10% thing last week and got the 5/8 OSB, only to find Lowes had 15/32 plywood for a few dollars more... so now I have both and have to take one back! I plan to test both just to see how different it is (i.e., fasten a piece in the garage and see how well it holds). The plywood is definitely easier to handle.

There's your answer. Only a few bucks more per sheet? Easier to handle? If the cost difference was only $100 or so, is it worth the risk using a lesser product?

At HD the difference was about $10 per sheet (x 50 sheets), so shopping around was a good idea. Now I just have to haul the extra OSB back... I've got an old 72 chevy that's my workhorse and the guys at HD were amazed at the fact that it held so much being a "mere" half-ton.

The lesson here is it pays to shop around. Didn't you know that both HD and Lowe's will meet a competitor's price? So if you find something at HD that is less at Lowe's, but you want to buy it at HD, all you need to do is say that and they will meet that price. You could have saved yourself and your old chevy truck a lot of extra work by comparing plywood costs prior to buying the OSB from HD. But I guess you know that now.

Exactly - the GC offered to have his assistant shop around and reported HD as the cheapest place - only to find the cheaper price myself later. Not sure why they didn't find the lower price. Then again, maybe he wasn't as motivated since it wasn't his money on the line.

You know the saying, if you want something done right, do it yourself

Then again, perhaps it should be: If you want it done cheap, do it yourself. If you want it done right... hire an expert.