Remodelers doing exterior work need to think about more than just what customers see on the outside of their projects. Any time exterior walls are opened up, there’s an opportunity to help clients fight one of the biggest enemies to their home and heath — mold.
These moisture-caused blights can lead to premature structural deterioration, shorten the life of exterior claddings and paints, foster infestations, cause a myriad of health problems — and lead to costly litigation. But remodelers can help prevent all these problems through proper water management techniques.
For exterior work, one of the best ways to manage moisture is using a new generation of housewrap called drainable wraps. These wraps use a water resistive barrier combined with a drainage gap for better water management. The newest products can be as much as 100 times more effective at removing bulk water from the wall than traditional wraps, according to manufacturers.
How can remodelers evaluate and choose the best drainable wrap for their project? Here are four key questions to consider:
1. Does it meet the code? The International Codes Council (ICC) has an acceptance criteria, ICC-ES AC38, which establishes guidelines for evaluation of drainable wraps. The key test to consider under these guidelines is the ASTM E2273 drainage efficiency test. For this test, water is run through a wall assembly to determine what percentage of it is drained away in 70 minutes. Look for drainable wraps with at least 95 percent drainage efficiency.
2. Is it omnidirectional? Some drainable wraps must be installed in a certain direction to work properly. But omnidirectional wraps work no matter what direction they’re installed, which makes them virtually foolproof. This feature is especially handy when working around odd shapes or bump outs.
3. What’s the climate? The Building Enclosure Management Institute recommends that areas with 20 inches or above in annual rainfall use a drainable wrap. Areas with 40 inches or above should use a full rain screen system.
4. What are the taping options? Traditional tapes can create a negative overlap and trap moisture that would otherwise drain down and out of the wall. Look for a drainable wrap that uses a double-sided taping system. This system creates a better seal without compromising the shingle-lap fashion install required by codes.
For more on choosing drainable wraps go to http://www.tamlyn.com.