Excellent resource for those building green, especially Passive House or Pretty Good House.We purchased the Prosoco R-Guard series of products: Joint and Seam, Fast Flash, and Air Dam. Very happy with how easy they were to install. Virtually bullet-proof against air and water intrusion if installed properly.We used mostly European-style tapes from Pro Clima for our air and water sealing needs, but I tried the Prosoco products around our front door, basement windows, and their Air Dam product to seal the gap between our insulated basement slab and the foundation walls.It was resources like World Class Supply that made our build possible; a Passive House in the suburbs of Chicago. You can read about the details here:www [dot] kimchiandkraut [dot] net

We have used World Class for about 3 years to supply my company with finishing products. I’ve never had an issue, or hiccup, ever. Reid Rollins is amazing to deal with, top notch. I just called this past Friday around 5:00pm and I left a voicemail to reorder finish. The finish showed up a few hours later Saturday morning. That’s service-

What a surprise and delight to find a building supply shop with so many options for green living. Do not pass it up!!