Best thing to do would be to go to Noble's website and read the pdf files on installation. Like most membranes, care needs to be taken when folding the membrane in the corners, at the membrane/drain intersection, how high the membrane goes up the walls, how the membrane drapes over the curb, and where to drive fasteners to attach the membrane to the framing and where to not use fasteners to attach the membrane to the framing. I'd wrote the book for you...but Nobel already has! And they have drawings/pictures! Best of luck with the project, Mongo

We are in the process of finishing our 1000 sf basement. All the walls are up, plumbing is in, and all that is left is a bit of drywall sanding, painting and laying of flooring (I plan to finish the drywall & painting this spring). Got a good deal on some engineered wood flooring last year, so that's been acclimating in the basement for about 3 months, and the Shaw Selitac should be here next week. Question: Should we still lay the 6 mm vapor barrier under the Selitac? Any reasons NOT to? Background: We live in East Tennessee, and there is some amount of humidity that comes up from the slab. The Selitac is supposed to take care of that (and we will, of course, tape the seams with the polyethylene duct tape). When we didn't run the dehumidifier in the basement last year and turned off our A/C during a poorly timed vacation, there was a small amount of mold on the baseboards. Understandable, since the humidity in the basement was almost 80% when we got back from vacation due to record-setting rainfall in July--it rained almost every day for 3 weeks while we were gone. Of course, hindsight is 20-20, and we realize we should have left the A/C and dehumidifier on. Took care of the mold issue with a buckets of stuff from Home Depot that turned the concrete and baseboards white, and the humidity has been at or below 40% since last August thanks to the dehumidifier and decrease in precipitation. Anyway, the point is that I want to make sure my basement floor is as impervious to moisture as possible since I and my daughters all have mold allergies and I am laying the floor myself this summer in my "spare time." Thoughts? Suggestions?

Be sure you understand the options. There are 2 kinds of crawlspaces allowed by the IRC: Vented and Unvented (aka "sealed"). The terms "unvented" and "sealed" are misleading because this type of crawlspace is not completely sealed or unventilated. The IRC code requires that both of these types of crawlspaces be "ventilated" so that moisture does not collect and encourage the growth of fungus (whether from the ground, condensation on the slab, etc.) by one of the following methods: 1) "Vented" Crawlspace - install vent openings in the exterior wall of the crawlspace 2) "Unvented" Crawlspace - inside the house supply to or exhaust from the crawlspace a small amount of air with a return air path to or from the house and insulate the exterior walls of the crawlspace. Both crawlspaces must have a vapor retarder at ground level and an access opening. For more information see IRC section R408.1, 2, & 3.

It is a requirement. You still need it and here is the reason why: We ALWAYS ASSUME that the "underslab" vapour barrier HAS BEEN or WILL BE compromised at SOME POINT in its life. We don't know when, we don't know how badly, but it will happen. Heck, it can happen WHILE they are POURING the concrete. Or when they are spreading concrete. Or when tree roots grow underneath the concrete, etc. So, the moral of the story is: always use vapour barrier (6mil poly sheeting = $0.11/sf at HD) over slab on or below grade when installing rigid flooring. It is the CHEAPEST FORM of "warranty saver" you will ever have. I promise you, that vapour barrier will come in REALLY handy at some point in the house's life span.