A: Yes, a reversible (left or right return) is available. Here is the link: https://www.homedepot.com/p/Stairtek-1-in-x-11-1-2-in-x-48-in-Unfinished-White-Oak-Reversible-Return-Tread-REWO1148-XXXXXSY/206178487
A: Yes our Red Oak, White Oak, Maple, and Hickory are all Proudly made in USA. Thank you Stairtek Customer Service
A: One major problem and one minor with your idea. The minor one is water and wood, especially if you have a freeze/thaw situation. The fortunate part is that white oak, unlike red oak, absorbs very little moisture and is not prone to the cupping, bending, and twisting that red oak can do when it gets wet. You major problem is the varnish, which I assume you will be using. Unless you use a spar varnish with a very high content of UV inhibitors you will have the age-old problem of the varnish flaking off after a few years. The UV rays penetrate the varnish, break down the outer layer of the wood, and then that along with the varnish breaks away from the main body of wood. Oops, just thought of a third problem. There is no way of know what type of glue was used in putting together the pieces of wood. If the manufacturer would come on here and tell us what they used it would be very helpful, since I like the idea of using these for porch steps. If I were doing this, and it was in a climate without extreme temperatures (some glues do not do well in very cold temps, or very hot for that matter), I would put on 2-3 coats of a very high-quality spar varnish prior to mounting. I then would mount them using face-mounted, small-headed 3" stainless deck screws. I would peg over the heads of the screws and then apply a final coat of varnish when in place (you could just varnish the under side with a couple of coats prior to placement and then do all of the rest after pegging the holes). After thoroughly drying I would apply anti-slip strips on each step, because they are going to get slippery with even small amounts of moisture.
A: Just got back from my local Home Depot and was able to look at the tread. No way it is for exterior use. I didn't realize it was a thin layer of veneer over a hardwood core. It would delaminate in no time if left outside. I'm not even going to use them inside. I want sold wood only. But I will say the veneer looked quite nice. Might work well with a runner in the middle over the oak tread.