Hi,

I have been tearing out 1"+ of particle board underlayment (with linoleum and carpet). Underneath it is a 1"x6" pine board subfloor on 2x8 16" OC joists (max unsupported span 10.5 ft). I have noticed that this subfloor is a little bouncy. The hardwood in the rest of the house (original-40+ years old is a little squeaky and sometimes bouncy). Would I be better off putting 1/2" plywood on top of this subfloor before installing the hardwood 5" Oak boards, or will it stiffen and remain solid (no bounce/squeaks) with just the addition of the hardwood flooring? If it is necessary to put down 1/2" plywood, should I glue and how should I attach it to joists.? Also, if I did this would it still be necessary to screw the 1x6 pine to the joists also? I would really like to end up with a solid floor that will last.

Thanks,
Bryan

I think 5" is the border line for having to glue in addition to nailing boards.(anything that wide or wider should be glued down) I would put 30# felt over existing pine subfloor then screw 1/2" CDX plywood to that using longer screws at places there's a joist. Then install 5" oak to that just like you would a pre-finished install(glue-down) except you would still be nailing boards like a regular nail down. In other words it would be nailed & glued. I've installed 5" (even wider) by just nailing, but that was over plywood that was over a moisture barrier on slab. The sub-floor your describing is a wood frame house w/ crawlspace so you would have seasonal changes under there and w/ 5" or wider boards I would be worried about movement. That's why I would: 30#felt, 1/2" CDX screwed, & nail & glue oak boards. My 2 cents.

Thanks for the reply,

Just to be clear, do you think that the 1/2" CDX will make the floor stiffer, more so than just nailing/gluing to the 1x6 pine subfloor?

BTW, I have a heated basement below this install, and I live in Colorado (pretty low humidity) and it has always been dry (10+ years).

Thanks again!

Yes, I think it would make the sub-floor stronger. If this install. was w/ 3/4"x 2 1/4" flooring I would say just felt & nail it to existing pine sub-floor but w/ 5" boards I'd be worried about movement. If you felt paper & then 1/2" plywood at least you'd be getting some kind of a moisture barrier w/ the felt. ALSO AN EASIER FLOOR TO HAVE TO REPLACE SINCE YOU WON'T BE GLUING TO EXISTING PINE SUB-FLOOR,but to the ply-wood that has been screwed (you can un-screw & repair/replace it if you have to)

Thanks again for the advice on the flooring...
I have installed the 1/2" ply and the floor is much stiffer....

Can you tell me more about gluing down the 3/4 boards? What kind of glue would you use? Would you glue bottom surface down or just end glue?
Thanks for all the advice so far....

If you have already screwed plywood to pine sub-floor hopefully you put down some felt paper between the two. It would help as a moisture barrier & sometimes wood on woood will have a tendency to want to sweak. As far as glue I use only Bostik's Best .Whatever glue you use make sure it contains no water in it. (since you are using a 3/4" solid you don't want water anywhere around it) Just call me on my cell, I'll advise the best I can . Kelly: 813.887.5124 (Tampa time) The type of floor your installing (3/4" solid) is the type I install. You'll find allot of glue-down installer's but this type of floor is a whole different animal. (to be done properly anyway) Just give me a call.

I wonder if you sholdn't take your phone number out in case you get inundated by calls.

As for the felt paper between the two subfloor layers, is that a common thing to do? It seems like a good idea, even though you end up using twice the amount of felt paper.

I'm not really worried about phone calls from people on this board. That's what I thought it's her for , to help people out. Also, reason for felt between pine board sub-floor and ply-wood being used would help any squeaks from wood on wood,provide an added moisture barrier, it's only $18.00 a roll, and if for any reason the floor was to fail the manufacturer,distributor, & inspector might try to say it shoulda been done if you didn't do it.