Moisture >>> Case Study
IMI seminar showcases ‘magic bullet’ for handling water in masonry walls
Water is a beast that has long feasted on the built environment.
Much of architectural history, in fact, has been about protecting buildings from water. Cornices, water tables, coping stones, even fearful gargoyles all serve dual purposes of decoration and destructive-water diversion.
Masonry cavity-wall construction is another ingenious architectural advance. It turns the structural wall into a drainage plane ushering invading water back outside through weep holes.
Yet, water seems to find a way. As vapor, for instance, water uses air to invade walls to do its damage, from creating favorable conditions for mold and reducing walls’ R-values, to rusting pipes and staining interior walls.
But the beast may have met its match in a fluid-applied air and water-resistive barrier applied in concert with a pre-assembled flashing system.
“We think we’ve hit on that ‘magic bullet’ that will solve many of today’s problems in our masonry walls,” said Jim Lucas of J.N. Lucas & Associates in Hammond, Ind., a masonry specialist and manufacturer’s rep with nearly 40 years of construction experience.
Lucas and the International Masonry Institute (IMI) unveiled that so-called bullet to contractors and architects in two seminars in Addison, Ill., in July.
They built the program around the construction of a 10,000-square-foot addition to the International Union of Bricklayers and Allied Craftworkers’ (IUBAC) District Council Training Center in Addison.
“We actually specified the general system,” said Project Architect Dave Jenkins of Larson and Darby Group in Rockford, Ill. “The products themselves came to us from the Bricklayers Union. They said ‘These are products we’d like to try out.’ They met the specifications we set, so we ok’d the products.”
For the air barrier, PROSOCO in Lawrence, Kan., supplied R-GUARD Spray Wrap and R-GUARD Transition Membrane. Mortar Net USA in Burns Harbor, Ind., supplied its new TotalFlash pre-assembled, all-in-one flashing system.
The original idea was to use the construction project to show IMI apprenticeship instructors the latest air barrier and flashing system technologies, Lucas said. As instructors, they have to be familiar with the newest systems in order to teach the union’s apprentice masons.
“Then I thought this could be valuable training for our area construction professionals,” Lucas said. “Architects, in particular, aren’t often able to get out of the office to see how the latest products work on real buildings.”
The IMI’s Scott Conwell, director of market development and technical services and an American Institute of Architects (AIA) member and construction document technologist, invited the Northeastern Illinois AIA members, and the area’s union bricklayers.
About 50 people showed up for the program the first day, and more than 30 the second day, Lucas said.
The mason contractors and architects watched as two IMI apprenticeship instructors applied a first coat of PROSOCO R-GUARD Spray Wrap to the training center addition’s CMU back up wall, north elevation. One instructor sprayed the wall, while the other back-rolled, as Lucas narrated the action.
The red Spray Wrap bars air and water from penetrating the block, which is extremely permeable to both. Because the fluid-applied air and water-resistive barrier is seamless and continuous, it also stops inside air from leaking out, carrying out heating and cooling energy dollars.
Then the instructors installed the pre-assembled panels of the TotalFlash Cavity Wall Drainage System. Like PROSOCO R-GUARD, one of TotalFlash’s purposes is to make installation fast and easy, Lucas explained.
The 18-inch-wide, 5.5-feet-long polymeric strips of flexible flashing include a number of built-in features, including pre-drilled termination bars and stainless-steel drip edges; no-clog drainage mattes and weep tabs; built-in edge dams and pre-formed corner boots.
Installation involves little more than screwing the termination bars to the block, and adhering the flashing to the R-GUARD-treated wall. Screws and adhesive come with the Total Flash package.
The systems’ comprehensiveness and simplicity help prevent installation errors that often compromise other flashing systems, said IMI Apprenticeship Instructor Janusz Chwalek, one of the seminar’s two applicators.
“It’s kind of hard to make a mistake with these products,” Chwalek said. “Of course, as with every product, they involve a little bit of training. But once you train people, they should have no problem installing them. They’ll work great in the field.”
With the flashing on, the instructors added a final coat of the air- and water-resistive barrier. Together, the two systems stop water penetration at the structural wall, then channel it back outside.
After the demo, the group went inside for AIA Continuing Education System presentations on air barriers and masonry drainage. AIA members got a CES Sustainable Development learning unit for participating in the air barrier class.
They got a Health, Safety, Welfare learning unit for masonry drainage, and the opportunity to self-report their hands-on experience observing the installations.
Lucas explained that, along with demonstrating how cavity wall construction reaches its full water-handling potential, the seminar also showed how mason contractors could add to their bottom lines.
“Masons are already installing insulation, doing the wire-reinforcing and flashing,” he said. “The air barrier would just be one more system they are fully capable of installing.
“For the architect and design professional, it gives single-source responsibility.”
The seminar drew positive responses, Lucas said. The architects especially seemed to appreciate seeing “up close and personal” how correctly designed and installed components of the building envelope work together to neutralize destructive water penetration.
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