Pro Clima founder, building scientist, and INTELLO inventor Lothar Moll along with Jens Lüder Herms, head of Pro Clima R&D, toured the west coast in mid-October with me (Floris) to present information, see common construction practices, and analyze how to improve the quality of construction. This trip also coincided with 475 opening of our west coast warehouse, which will make shipping Pro Clima airsealing and vapor control products quicker and more economical west of the Rockies.
Vancouver – Make it tight training with CanPHI West
The tour started out in Vancouver with a 4-hour “Make It Tight” class, organized in cooperation with CanPHI-West. Filled to capacity, the attendees received an intro by Monte Paulsen, followed by both the theory and practice of airsealing. Since the Vancouver has had a lot of issues with leaky condos, there was a focus on what caused those issues, especially when there is an increased focus on airsealing and insulation, which will make the exterior of the walls colder and inherently dry more slowly.
Did these leaky condo issues/damages occur from exterior wind driven rain leakages? Or could additional moisture also be entering the assembly from inside? It was shown first, with WUFI Pro models that have real airtightness on the inside. Using vapor variable INTELLO membrane keeps the wall much dryer and safer in winter, while allowing it to dry inwards in the summer (making the intelligent airtight system). As was pointed out (and demonstrated) the crucial connections for this interior air barrier and vapor control layer should be tapes and adhesives that are both healthy (ultra low-VOC or VOC-free) and last the life of the building. Pro Clima recently concluded the 100-year durability testing of their tapes, which shows we’ll have reliable/permanent airsealing with their SOLID acrylic TESCON tapes – assuring the buiders, architects, and consultants that the performance of their building will last.
The application of the Pro Clima tapes and membrane in the hands-on demonstration were done on mock-ups skillfully built by Smallworks. The participants spent the next 25 minutes applying EXTOSEAL ENCORS (a bullet-proof window sill), TESCON PROFIL (as interior airseal to the window), seal pipes with ROFLEX gaskets, and applied SOLITEX MENTO 1000 over the sheathing.
Lothar demonstrated how SOLITEX monolythic/non-porous membranes can be instrumental methods to keep the wall dryer from exterior driven rain, while at the same time increasing (by being actively vapor open) the walls’ drying reserves. This results in safer construction and reduces the mold growth potential, especially in climate like Vancouver and Seattle where wind driven rain should be kept out of the shell by high quality (Pro Clima) weather resistive barriers in combination with detailing of overlaps, with particulair focus around windows (heads and sills) as shown above. Detailing and construction of membranes and tapes that direct water out (not in) is the best protection against moisture ingress – leading to even higher protection and safer construction. For more information and support for these kinds of west coast/coastal detailing, WUFI modelling for your assemblies, please contact 475.
After another round of hands-on instruction and taping practice on the mock-ups the day ended with dinner and networking, during which, many of the details and issues of thicker walls, construction moisture, and airsealing complications were worked out.
After a train ride to Seattle, and an evening presentation given at Living Building Challenge/Bullitt Center, again the need for both the interior smart vapor retarding solutions and exterior vapor open waterproofing details was apparent. The need for this also became clear during the next day’s site visit at YSBuilt – as it was classic NW weather – pouring relentlessly. Their double-wall construction showed that high performance is happening in the NW and that the details are being developed to create continuous airtight construction (as shown in the photo above on the right).
The moisture we encountered on a construction site nearby made clear that we should, as we do assume in WUFI studies, be conservative and load a good amount of moisture into the assembly – so we can see if there is sufficient drying reserves in the wall which will allow this moisture to dry quickly out within the first year(s). This is especially crucial, if there is vapor retarding sheathing (OSB or Plywood) on the exterior side of the studs – as shown below.
Stopping by Adrianne James’ project in Seattle was a joy (see photo below on the left – Floris, Adrianne, and Lothar). It’s a great looking Passive House that she and husband Clayton are building together. The airbarriers (DB+ on the walls and INTELLO in the roof) have been installed and taped with Pro Clima TESCON VANA/UNITAPE and reached below 0.6ACH50. She gave us a tour of the house, and we were impressed by the quality of the installation.
On the drive from Seattle to Portland we visited a not-so-high-performance job site, with return ducts in attic, vented (insulation+) roof sheathing, and other elements of code minimum construction which do not follow Pro Clima’s credo: “… and the insulation is perfect”. Again this showed us how much and how simply we can improve performance of assemblies, with details, solutions, and materials that make it easy to execute and verify installation quality. For instance not stapling the membrane at random a million times (see 2nd photo on the right).
Last stop on the tour was a presentation at AEA in Oakland. Passive House California was well-represented and we had a lively discussion over climates during the presentation – we had WUFI-ed with San Francisco climate, and the surrounding climates are clearly different. We spent a lot of time discussing the best performance of wall assemblies in the milder Mediterranean climates of the area. If one can simply airseal the sheathing, add exterior insulation (vapor-open of course) to have an acceptable wall; or if it would be better to airseal on the inside, contain the fibers in airtightness, and optimize the insulation and drying – which has the added benefit of helping the interior air quality and gives the architect/builder the most robust enclosure. Another benefit of this interior airsealing approach is that the airbarrier is warm, can be visually verified and easy to reach and fix in the blowerdoor.
We all enjoyed the trip and learned a great deal. Last year Lothar did an east coast tour and we look forward to planning the 2015 North American tour in a region we haven’t traveled through yet. Stay tuned…