We are having a professional come and give us a quote tomorrow to refinish our existing red oak floors, add (extend) the red oak into the living room and possibly install it on the stairs. We have two dogs (thick nails) and get traffic from the deck to the breakfast area (Colorado snow). What questions should we be asking? We want it stained a bit darker and want a very good, strong finish for the top coat (he mentioned something about commercial grade to use when I initially called him). Thanks.

Yes. I have sanded and finished subflooring for customers. Really no different from any other flooring finish work, except that you have to consider the fact that it happens to be a single construction floor system and, therefore, you have to take steps to protect what is below the floor when you sand and then apply stains and finishes. Anything you do above to the floor surface can easily find its way down to the space below...dust, stain and finish. You have to sink any top nails below the surface of the wood before you sand and continue to punch them below when necessary. You probably can never remove all tar paper lines and staining, but that is OK, as the floor will have a great look all by itself. I have finished these natural and stained a few. I also colored one green once at a customer's request. That one was unique and beautiful.

You need to do a little more archeological digging still. You need to know the whole construction of the floor before you can decide how best to install something new. I'd take up that plywood piece in the kitchen and see what's under it. It's higher than the surrounding floor, so needs to go. You should also be able to see from there what subfloor is under the original kitchen hardwood. It's too bad the space under your entryway is finished, but I'd still do some exploring from below to see what's under there, and to figure out the fix to stop it from squeaking. Is it drywall below or a drop ceiling? I know it probably seems like a pain to tear out drywall, but if you cut out a clean patch, like 2' x the width of the joists, it'll be relatively simple to repair. Just make sure to cut it down the center of the joists so that there's room to screw the patch piece to it later. Cut the hole under the area that squeaks the most, if you can. Have someone walk on and watch the floor from below to see what's moving. It might be as simple as pounding in a couple shims from below, or face-nailing a loose board from above. You want to find out what's underneath the hardwood. It might be laid directly on the floor joists, or there might be 10" wide boards that the hardwood is nailed to. Another thought is to take out a board in the hallway, since that's not original and you want to replace it. See what the subfloor is there. I am a bit puzzled at why, when you've stripped the kitchen down to the original hardwood, it's still higher than the hallway floor. Is your current surface perhaps not the original kitchen hardwood? Peeling back the plywood area will help determine that. BTW, I haven't heard of that stop squeaking product you linked to, so can't offer any personal opinion. And don't pour self-leveling compound over top of hardwood. It needs to go over plywood.

Last year I bought a house built in 2003 with beautiful oak hardwood floors. My only problem is that there are many layers of some sort of shiny clear finish on this floor, and trapped within these layers is all kinds of actual dirt and assorted crap. The home was previously owned by an elderly woman who couldn’t see well. I am guessing she had a love affair with Mop-N-Glo, or something similar. As far as I can tell she just kept putting down more Mop-N-Glo (or whatever) on top of the dirt. The floors shine beautifully in the sunlight and if there wasn’t obvious crap also reflecting in the sunlight I’d be inclined to leave well enough alone. (She fancied herself an artist, and also loved glitter. Trapped within this clear coat of whatever is glitter. Everywhere. There are also paint splatters, and actual little mounds of actual dirt. It’s driving me crazy.) The floor itself is in great condition, so I was hoping a screen and top coat would work. I’m fine with the color of them. But as I was poking around on the internet, I saw something that said a screen/top-coat won’t work if it goes on top of a product like Mop-N-Glo…? If I have to do a full sanding…how bad is it, really? I have forced air heating and I have visions of dust coating everything in my house. It sound like between the dust, debris, and smells, I will have to move out of the house for a week or two, yes? I appreciate any thoughts on how to best deal with this, and thank you!