Considering the most often asked qusetion when it comes to nailing or stapling hardwood floors is what kind of subfloor is proper, we've placed this message in a "sticky mode' so many don't have to hunt for the answers.
More information on the subject within our site at these links:
Nailing or Stapling Hardwood Floors
Layout- Which Direction To Install
Racking Out The Floor
Pictures tell it like it is.
You don't want to nail or staple hardwood floors into this. True particle board does not have the capacity to hold nails or staples.
If you have a subfloor that looks like this, you may be able
to nail or staple hardwood floors into it. Always consult the individual manufacturers specifications.
Anyone wishing to offer other tips, suggestions, ideas, corrections please let us know.
Contribution From Gary of Antioch CA
Added to this thread--January 8, 2004
Posted: 30 Dec 2004 08:59 pm Post subject: Wood Subfloors
Since this topic comes up alot and there has been some misunderstanding and misinformation, I thought I would clarify it for you DIY'ers out there.
First let's talk terminology. It is importamnt when asking technical questions. So................
Subfloors......... Are the deck/wood floor a home is built on. The subflooring can be different materials and is always attached directly to the joists/trusses. Go in your basement/crawlspace and look between your joists. That material nailed to the tops of your floor joists is your subfloor.
Underlayment.............. If your have a vinyl floor in your home and you have wood subfloors, most likely you will have underlayment. Underlayment is used to provide a smoother substrate for some floor coverings, like sheet vinyl. It is also used to raise one area up to be even with another floor. It is used to provide a suitable substrate for tile ( like Hardi Backer Board) and used to stiffen the subfloor. It comes in many types: particle board, plywood, OSB, cementious tile backer board, sheet rock has been used, luan, masonite, etc. And more are being developed all the time. Underlayments are not subfloors and subfloors are not underlayments. Underlayments can be safely removed; subfloors should never be removed EXCEPT for damage or remodeling and only by licensed, knowledgeable contractors. Underlayments always go on top of subfloors and are usually stapled but can be nailed, glued, screwed, etc.
As far as wood subfloors go, this is what NOFMA (National Oak Flooring Manufacteres Association) and NWFA (National Wood Flooring Association) have to say. All solid wood floors should be nailed down (nail, staple/cleat) to an approved wood subfloor. Approved wood subfloors are listed in order; best to least preferable.This is based purely on the materials nail holding capability.
BEST: 1" x 6" solid #2 or better douglas fir or frame grade pine boards installed diagonally across floor joists 16" oc.
NEXT: 3/4" T&G Sturdi Floor plywood subflooring installed at 90 deg. to joists 16" oc.
Next: 5/8" T&G plywood subfloor installed at 90 deg to joists 16" oc.
Next: 3/4" OSB (Orientated Strand Board) T&G subflooring installed 90 deg to joists 16" oc.
There are other, older and not used anymore subfloor systems one may encounter. Such as: 1&1/8" T&G plywood subfloor installed at 90 deg to 4x6 beams spaced 4' oc.
1&1/2" x 5" T&G solid fir deck boards installed at 90 deg. to 4 x6 beams spaced 4' oc.
1x8 solid fir/pine boards installed at 90 deg to joists spaced 16" oc
1" RED-X T&G particle board subfloor installed at 90 deg to joists spaced 2' oc.
3/4" or 5/8" particle board found mostly today in modular and mobile homes.
These subfloors should NOT be removed but overlayed with 1/2" CDX plywood that is well stapled (2" around perimeter and 6" oc.) or glued or screwed. In all cases, subfloors and underlayments are to be flat to within 3/16" in a 10' radius.
When gluing down an engineered floor over a solid lumber subfloor, you will need an underlayment of 3/8" plywood, at least. When gluing down to a plywood or OSB subfloor, many are tempted not to use an underlayment. I prefer to use a 3/8" plywood underlayment over a plywood subfloor when gluing down a wood floor because if the floor needs to be repaired or replaced, it is easier/better with underlayment than with the subfloor.
I hope this clears up many of your questions regarding installing wood floors over wood subfloors.