I have heard various discussions about laying full 3/4 hardwood floor directly over OSB. I will be putting down HICKORY STRIPS OVER 3/4 T&G OSB. The orientation of the strip flooring will be parallel to the floor joist which are 12″ TJI on 16″ centers. I am wondering if I should add some plywood as additional subfloor and if it would be better to staple or nail the strips? I also do not want to put roofing felt as underlayment as my family has allergy issues. Do I need an underlayment and what might be the best or greenest?
Thanks
budnature
Replies
OSB does not hold fasteners well, regardless of flooring type or orientation to joists.
Rosin paper will do just fine as an underlayment instead of felt.
J. D. Reynolds
Home Improvements
Pp, Qq
The OSB should be fine but I would not run the HW parallel to the joists I would run it perpendicular which is what I think the National wood Flooring Association recommends. If it must be parallel and the OSB has deflection you might look into at least 1/2" plywood but how much do you want to build this up in relation to other floors? Adding layers increases the chance of squeaking. Felt is my choice and will be fine it is recommended by the National wood Flooring Association. But Rosin paper works too I like felt it is heavier. Cleats or 15 gauge staples will be fine also might get a little more hold with cleats in this case(OSB).
Here is a link http://www.osbguide.com/pdfs/EL813.pdf
Wallyo
Edited 4/3/2008 11:34 am ET by wallyo
Are we talking regular osb or Advantech?
Good question I use Advantech and Coated staples and floors never lift.
(well I guess I should say have not yet Advantech has not been around long enough for me to be say Never)
I would not run the flooring parallel to the joists it should run perpendicular to the joists and i would make the location of the joists on the wall (at the bottom where the base will cover your marks) before you put down the paper then snap some lines and as you nail the flooring try to get as many nails or staples at the joist locations it will hold better. Not all the nails will be in joists but enough will that the floor will hold better. 3./4 plywood sub-flooring does hold better then Advantech but I have both in my own house
now side by side in. I took down a wall between two rooms to expand the kitchen eating area the small room had Advantech the kitchen had 3/4 TG ply. after joining the two rooms to one I installed 3.5 inch wide Pre-Finished Oak and both areas are holding equally well. My problem is more my damp dirt floor basement which causes too much moisture and it cause the all the flooring in the house to buckle in summer and then the floor shrinks causing gaps in winter but I know it is the damp basement not a problem with the nails not holding in the AdvantechI did put a moisture barrier down before the subfloors but since when you nail the flooring you put a puncture it with bunch of nail holes it is not very effective. The solution would be to get the dampness out of the basement but that is another project yet to come since it is a very old house with dirt and stone foundation sealing all the moisture out would be a huge project. (in some area the foundation was just a trench filled with loose stone with a few larger stones on top to rest the sill beams on.
bud,
With the 3/4" OSB, you have nothing to worry about, especially if it is the advantech or equivalent. There's only 14" of OSB spanning between the joists - once you have reinforced it with 3/4" hardwood strips, nothing will make that sag no matter which direction you run the flooring.
Fastening is not an issue either. I used to use glue coated staples whenever possible. I have sometimes had to pull a piece of wood off and found that I would have to pull the staple through the board, leaving a wafer of wood enclosed in the staple's jaw. It isn't easy to withdraw a coated staple from OSB.
I recommend staples first, if they will drive into the wood. They aren't much use in very hard wood. I don't know anything much about hickory so can't say what would be best.
Flooring is still laid with uncoated sheathing paper underneath. No VOCs. I have also seen newspapers under old flooring. Asbestos paper was common one time too. No allergy problems with that either, but it might be hard to find. And there are worse things than allergies.
Ron