We used a polyurethane-type waterproofing under a glued-down BR-111 (tigerwood) floor in a below-grade (basement) slab. It was WP'er, then mastic, both were specific to the conditions. The floor has been fine for 2 years, going on 3. Neither of the products were low VOC, I'll tell you. Lots of brain cells were sacrificed. The aroma was very transitory, though. I think VOC's will be part of the formula for a product to accomplish this task successfully. Casey

Thanks for the feedback. As for covering terrazzo...I am not a fan, and vastly prefer hardwood. However, please don't weep, as my husband and I have commented the floors are just covered up. Someday no doubt a future owner will be exclaiming as they rip out my flooring 'Can you believe someone covered up these amazing floors?'. Just as today the same comment is heard while the carpeting is peeled off old wood floors :).

What a wonderful website. Very informative. Thank you very much. It did not really address the underlayment part of my question but I suspect that I will just need a typical foam cushion under the floor. I will post that question in the applicable forum. Thanks

Hi Mongo! Thanks so much for responding! The underlayment I saw was Titanium UDL (on a Bob Vila episode). Seemed interesting but kinda newish. Not sure any of the roofers I get out here will have ever used it, but it interested me enough to find out more about it. We will be using asphalt shingles. Based on a back of the envelope calculation, we likely will go with the class 3 or 4 product because we do get a break on our insurance premiums. I'll make sure whatever shingles we pick meet those guidelines you set forth. As far as the radiant barrier, I already have several of your prior posts printed out and in my attic/roof file. :) Right now we're still in the early planning stages, but I really like the way you did your attic with the faux beams. You had FG batts between the rafters, closed up the rafters by putting the polyiso over them, then furring strips, then drywall, right? Currently, our attic is pitifully insulated, and our air conditioning ductwork in the attic (for our 2nd floor rooms) definitely doesn't meet code and is poorly balanced. When we finish out the attic, we're going to pay particular attention to the insulation and have all the duct work re-done. I've saved your postings comparing insulation types and about the radiant barriers (like the polyiso). It's been incredibly useful -- I don't think I've ever posted on the remodeling forum, but you've unknowingly helped me so much already! We're still debating how much of the attic we're going to DIY and how much we're going to use contractors for. We're definitely hiring a roofer and a framer (for dormers & such). I really want all that done "together" so I've been trying to get my ducks in a row regarding insulation, roofing, ventilation, etc. before any of the work starts.