COLUMN BUILDING SCIENCES PHOTO 8 Base of Wall Flashing. Installing a " seat " in concrete slab at the perimeter handles the rainwater draining down the CMU block cores. The seat acts as flashing, directing the rainwater to the exterior of the wall. FIGURE 8 (LEFT) CMU Block Wall Window Rough Opening. Note the " tiered " concrete rough opening sill. FIGURE 9 (CENTER) CMU Block Wall Window Rough Opening. Note the wood " rough buck " lining with a " back dam " wood strip. FIGURE 10 (RIGHT) CMU Block Wall Window Rough Opening. Note the fluidapplied coating around the entire perimeter of the rough opening. PHOTO 9 Fluid-Applied Flashing. You absolutely must use a fluid-applied coating around the entire perimeter of the rough opening. fi nishes are vapor open. There has to be a catch. There is. Lots of moisture in the concrete when we cast it. We need to let this moisture dry to both the exterior and the interior. Or-wait for it-line the inside of the concrete with something to throttle the inward fl ow of moisture in the concrete if we insulate and fi nish the interior of the wall GET AQIP-CERTIFIED Reduce Callbacks Our new Armacell Qualified Installer Program (AQIP) combines online learning and hands-on training for companies who want highly-skilled and efficient installers who will get it installed right...every time. // Better installations with fewer callbacks save money // Inclusion in our qualified installer referral database // Promoted through Armacell's digital channels // Valued at $250 per trainee-offered free of charge Scan the QR code to learn more! www.armacell.us J U LY 2 0 2 2 ashrae.o rg ASHRAE JOURNAL 45 before the concrete is " dry enough " to not damage the interior fi nishes as it continues to dry to the interior. References 1. Lstiburek, J. 2005. " Rainwater Management Performance of Newly Constructed Residential Building Enclosures During August and September 2004. " Florida Home Builders Association, © Armacell, 2022http://www.armacell.us http://ashrae.org