1/2" site finished ... you mean like an Owens Plank unfinished engineered material?

hmmm...not sure if it is Owens. I do know that it is solid unfinished red oak, not engineered. They will install, then finish it on site.

As I understand it, engineered floors are supposed to last as long as solid because you can only sand away the top one eighth of an inch, even on a solid floor. I'm not clear on why, perhaps it's an issue of how even and flat the floor would be after sanding more than that.

If this is accurate, then the half inch will last just as long as the 3/4.

It would be a pretty easy choice for me: I love quartersawn!

Koetter Woodworking makes 1/2" thick solid quartersawn flooring in a variety of species. The thickness of the wear layer (1/4") is about the same as with traditional 3/4" thick flooring. I considered getting flooring from them because they are close by and have a good reputation, but found out they only sell through professional flooring installers which wouldn't work with my DIY job.

Many engineered wood floors have very thin surface layers (1/10" or less) with cheaper plys below. With such floors, you either replace damaged planks individually or just replace the whole floor (disposable).

Here is a link that might be useful: Koetter 1/2

We just installed wide plank quartersawn oak a few months ago and it is 3/8. Bought them from Launsteins. They have a very informative web-site too. I think it was reasonably priced and it is certainly beautiful. I don't think we could sand it as many times over the years as the regular thickness, but frankly we have been in our house 8 years and have never sanded our other wood floors (Bruce).

Here is a link that might be useful: wood floor

The Launstein brand is highly respected.

check hurst hardwoods. I am getting ready to purchase 3/4" think quartersawn white oak for $4.39 sq foot, unfinished, in 4" wide planks. It is select and better grade. I think it's a great deal!

Here is a link that might be useful: hurst hardwoods

If your refinisher sands 1/8 inch away from your floor on a resand and finsih he is a hack. Usually 1/16 or so is all that is needed.

3/4" of course will last longer. But quartersawn oak is so hard, I doubt you'd wear it out in your lifetime, even at 1/2". (This is an educated guess, but I'm not an expert.) That is unless you're particularly hard on your floors with lots of dogs, kids throwing heavy toys around, unusual traffic patterns, etc! In that case the polyurethane will wear out faster and something will need to be done to protect the wood. I've heard of "screening" but don't know what it is. If it's something that just takes the poly off for refinishing, you don't have to worry about removing wood thickness.

Another thought: quartersawn oak has a characteristic look. It sounds like you like that look a lot, but maybe you don't need to put it on your floor. Plain sawn oak is still beautiful, and you could use the quartersawn oak in furnishings instead. They'd probably draw more attention than the floor.

Floor width: With 4" you'd see l lot of the grain pattern in plainsawn oak, in 3 1/4" less so. Also, 4" is a very nice width, IMO, but it does give a different impression. I think 3 1/4" widths just about still give the impression of strip flooring that you associate with older construction and urban buildings. 4" just has a different look. It's hard to explain, but it's a little more informal I think, maybe a little less urban feeling. But really I think that's splitting hairs. Both will be very nice and I think you'll find that once it's down, you won't ever look at it with the scrutiny you use when you're planning it.

One final thing: If you go for plainsawn, keep in mind that there are different grades. Getting it from a private mill might give you the best quality. Your typical commercial premium is next best. After that the quality gets crummy, IMO, with lots of short lengths, some knots or stains, and variety in coloration of boards.

Quartersawn is chosen not just for the look, but for the stability of it. It is no harder than plain sawn....just cut differently. Plain sawn wood cups, expands and contracts....quartersawn does not. When you buy quartersawn wood, what you actually get is a mix of rift cut and quartersawn. They are both cut the same way....not like plain sawn, but rift cut boards have almost no grain pattern at all. The quartered boards have the disticvtive "tiger" stripes and rays. Still, the look is much different that that of plain sawn.

Quartersawn can cup too... it just takes alot more to make that happen.