We are doing all the millwork for a historic building. We removed the original wood flooring and plan to mill, resaw it and vacuum bag it to 1/4" baltic birch in a parquetry pattern. We will make 3' X 3' panels/tiles and lay those onto of the 1 and 1/8" subfloor. I would love to talk to someone how designs engineered wood flooring or has experience with doing this. I know this tile will be unbalanced, but once glued to the subfloor, I think there will be no issue.

What species was the old floor? How thick will the solid wood be on top of the plywood? I've been taught that anything over 3/32" will act like solid wood and not veneer. It will cause huge seasonal wood movement issues if glued to plywood. What is the subfloor material? All your gluing talk has me very concerned. Never a good situation to try and restrict all wood movement by gluing everything down tight.

Hey Rich, those are good questions. The old floor is old growth long leaf pine. It is pretty stable. I'm thinking my thickness will be closer to 1/4" so that there is plenty of room for future refinishing. The floor has been down for more than 120 years, and the idea is to make it last another 100. I can't lay down a veneer so thin that it can't be refinished in 20 years (or every 20).The subfloor material is very stiff. Huber Advantech Subfloor 1 1/8" thick. The seasonal changes should be minor since the HVAC will control temperature as well as humidity. 70's year-round with a consistent 50% relative humidity.

If your planning to glue directly to the Huber I will warn you to speak with some flooring contractors in your area and do a lot of research. Advantec is impressive stuff but its an absolute b&tch to stick stuff to. I would even argue that most construction/subfloor adhesives dont adhere long term (joists to huber) but its goes unnoticed because the Advantec is so stable. We were recently on a job where a carpet floor tile was failing over Advantec and all manufacturer guidelines had been followed even applying a primer over the Advantec days before the flooring install and it was pretty much all coming up.

There is so much resin in Advantec (which makes it what it is) that it can be very hard to get thin bed adhesives to stick and thats further compounded by the fact that your laying your flooring after months and months of traffic, dust, burnishing, and so on, with the Advantec exposed to all that traffic.

The unbalanced thing is definitely a concern with a 1/4" top layer but theres no reason you cant balance that with a similar material on the back side if your concerned with it. My bigger concern would be relying on anything bonded over top of Advantec. I love the stuff and have used many many units of it in my GC days but I would never trust any bonded floor over top but thats just based on my experience and what Ive seen others deal with. Im sure some bond over top of it and feel they have no issue.

Most of the good flooring adhesive companies offer a sealer/primer. Might be worth it to slather a coat on before you start bonding down the flooring.

Advantech coating