In regards to using OSB, I have the following comment: I am a structural engineer in California, and I have specified OSB as a subfloor, roof sheathing & shear wall sheathing for hundreds of homes. As far as an underlayment for hardwood floors, there appears to be two issues. 1) is the floor structurally sound for hardwood, and 2) whether attaching the hardwood directly to OSB will result in nail slippage many years down the road. I have comments on both issues. As far as the floor being structurally sound, I have seen a few posts on this issue & I am not one to automatically say that hardwood should be placed perpendicular to the floor joists... But it would definitely be stronger and may help in easily repairing the hardwood attachment if the nails should slip many years down the road. I myself have placed the hardwood parallel to the floor joist because my subfloor is very stiff. To get a stiff floor, this is my recommendations: joist spacing should not exceed 16"o.c.; floor joist span should be designed conservatively (building code minimum is not conservative), and floor sheathing should be 3/4" nominal and placed with the face grain (long dimension) perpendicular to the joist & staggered. In regards to item 2: some national floor associations have said direct OSB attachment is acceptable as long as sheathing is PS2 standard & 23/32" minimum. That is all we can go by. As I mentioned above, let's say the nails do slip after many years... If your hardwood is perpendicular to the joist, couldn't you just screw it down to the joist below as a repair? That is one benefit I can see with placing the hardwood perpendicular to the joist or adding blocking between the joist. In regards to nail slip, I posted a blog regarding using the hardwood nailers that drive the cleats at an angle in the tongue of the hardwood edge. The cleats are locked in place inside the T & G connection. How is this going to lift up? Also when you drive the nail at an angle, there is a vertical bearing component of the nail that is preventing the nails from lifting. This is versus using a brad nailer that goes vertical. The vertical nail would rely totally on friction between the OSB & nail and I can see this possibly slipping down the road.

My two daughters (currently living at home) both wear spiked high heeled shoes. I don't. My floors have not been damaged by their heals. The red oak floors is very hard. Several years ago, we had heart pine floors and had a babysitter come in with high heels (go figure!) and she left a trail of little pock marks all over the house. I just chucked it up to character and let it go. It was nothing worse than what the cats did to the dining room table, or the dogs nails did to the floors, not to mention what the children have done to our houses over the years. :)

*chuckle* You just gotta take the research in tiny bites - probably the same way you do research for your kitties. Do you get the FM Network newsletter/E-News? That's my starting point for a LOT of things, that and the CFIDS Chronicle. Both boil down the current research into something the average brainfogged FMer can gnaw at, winnow out the junk, and I go from from there. I also HAVE had this crap since 1994, and that's a lot of time to pick up stuff. Unfortunately, having no specialists where I can get to them, it's kind of my responsibility to find this information and bring it to the professionals if I want to get anything done. Right now the deal is that I'm 3/4 of the way through a slow tapering-off of a mega-strong pain medication I've been taking for about 6 years that hasn't been working as well in recent months. Pain level through the roof and coping with that really takes it out of you as you know, fighting for every minute of sleep and the physical upheaval set off the cascade of everything else in the "package" flaring up. Big snowball effect. Whine whine whine. :-) I'll be around some (if only out of sheer boredom heehee), but writing is taking me a long time since I'm taking a lot of breaks and the fog means a lot of rewriting to (hopefully) say what I want to say without being TOO much of a b*tch! :-) I'm looking into what else can be done, prying all my old records out of the doctors I've seen to clarify my (bad) memory of what's already been done, what side effects I had, etc. I do think of you every time I chuck down a few Flexeril, though. :-D Thank you for the happy thoughts. A kitty is probably going to come along late next summer. We wanted to get one this winter, once we were mostly unpacked, but we're having problems with free-roaming cats taking up residence under our porch and using the area as a toilet. It reeks to high heavens, and sometimes the smell comes into one part of the house, and I don't want Puss to get confused about where she's supposed to go. We had that problem with Random in our condo; the neighborhood wanderers urinated on the balcony by the door and on the front stairs, so she would pee near there inside, and of course both locations were not places we could put a litterbox! It's going to be a helluva mess to clean that out and repair the porch. I've considered getting some of the Havahart traps but there's nowhere to take them where they won't be killed, and all the feral-cat programs have to offer is trap-neuter-release which is a really lovely idea but does nothing to mitigate further destruction. Sigh. Letting one's cats roam free is almost standard practice here, unfortunately.

FYI, I found a solution to the same kind of prob as the original poster. A cheap woven rug made of synthetic materials had "etched" it's pattern onto my floors (which were red oak with a satin water-based polyurethane finish. And BTW, I did NOT put the rug down until several years after the floor was finished). Tried rubbing alcohol first, but it seemed to actually sort of "melt" the finish a little, and even though it helped a little, it seemed way too dangerous to use, I mean it seemed like it would just remove the poly finish if I rubbed too hard. So simply I tried LIGHTLY rubbing with "0000" steel wool (WITHOUT using any alcohol or mineral spirits or anything) then lightly buffing by hand, and it worked like a charm! Hope this helps.