Question regarding basement subfloor options. Amdry panels vs Rigid Foam Panels with Plywood
Greetings. I’m a long time reader of this website and a first time poster. I’ve learned so much from this community, but now I’ve got a question that I’ve been unable to find the answer to so far just by reading articles or Q+A posts.
I’ve been slowly working towards finishing my basement. Starting with insulating. My goal is to essentially turn the basement into a styrofoam cooler and then begin the “finishing” part once it’s sealed and fully insulated. To date we have put 2 inches of closed cell spray foam on all rim joists, added two inches of rigid foam board on all walls. The boards have staggered seams that are taped, but also bonded with spray foam. The foam goes from floor to rim joist. The crawl spaces are sealed in the same manner, except that I also put 2 inches of foam board on the floor with staggered seams that are taped and foamed.
As of yet the main basement part still has a concrete floor. The home was built in 1992. I can’t be sure that plastic sheeting was put under the slab so I am assuming that it was not. In a previous article (https://www.greenbuildingadvisor.com/blogs/dept/musings/new-green-building-products-june-2013) Martin seemed to give a favorable review to the AMdry Subfloor system. It would provide adequate insulation beneath the subfloor material, but I’m leery of it’s ability to stop moisture vapor from coming up between it’s joints. I don’t see how it’s connector system could possibly be vapor impermeable. After that initial write up from Martin I haven’t heard anything on this website about AMdry panels as a viable solution for basement subfloors and that raised my suspicions about them.
Obviously rigid foam panels glued to the floor with sealed seams and plywood over top tapcon’ed 6-8x per panel would be as perfect as one could hope for, not to mention cheaper. But my basement is is large and my the thought of attaching 50 full sheets of plywood to concrete with a hammer drill is daunting considering my elbows are already injury prone.
At the end of the day I want to do the best job, but I do have to weigh the installation time and joint damage. Do you feel that AMdry panels can provide adequate protection from adsorption on their own or would I be taking to much of a risk by foregoing the tried and true rigid foam route. I should note that I will not be carpeting the floor. It would most certainly by LVL over the subfloor.
Thanks for any and all help.
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