A Typical Swiss Building II

While the habitable construction of this building is Wood CLT's (cross laminated timber's), there is a concrete and masonry exterior staircase. The two elements are separated (sorry... I thought I had a better picture!) by a layer of 6" Rock Wool high density panels between the two. The rock wool is also an exceptional material in my opinion and blends well with both masonry and CLT construction. Its R 4.3 per inch, vapor open, and inert. It resists rot, bugs, fire and most anything you can think of. I think it's a great companion to wood construction because it will insulate at the exterior while letting the wood absorb and release moisture as it needs to. Functionally its dense enough to make an exterior house wrap redundant and won't be harmed by driving rain penetrating the facade.

With a combination of Masonry, CLT's, and complimentary exterior insulation like rock wool, it's possible to prefabricate all of the building major components in an indoor controlled environment and then set the building structure in the field quickly, plumb and wire in service cavities at the interior, and add a continuos thermal insulation layer around the entire exterior, while providing a thermal break to exterior masonry elements. All in all it looks like a very efficient and high quality building process. I'm happy to say that while CLT's are now common in Europe, there is now a company in Montana working to start up the first CLT plant in the US. You can find them here: http://www.smartwoods.com/. It's a big step to bring this lever of building quality and planning to the US market and I'm hoping that we continue to see growth in the area's of material quality, as well as energy and construction efficiency.

Since I was in Switzerland to learn about air sealing technics and products from the Swiss Company Siga, then of course the air sealing products were Siga. Regardless of the vendor, what you see here is typical for the central european climate region: An air and moisture barrier at the interior that is protected from damage by aservice cavity, and then a vapor diffusion gradient increasing to the exterior. In this case it's accomplished by the Siga white membrane Majpel (.68 perms) and the yellow Sicral tape.

And below joining the Majpel membrane to masonry with the Primur Roll. 

Next post: The bio mass in the basement.

A Typical Swiss Building

While in Switzerland, I got a chance to walk a job site with Patrick Haake of SIGA. This building is a typical construction for the region. "Typical" is either a massive construction of ceramic and concrete block, or Cross Laminated Timber (CLT). In this case it's concrete from the parking garage to the ground level shops (framed in steel studs) and then CLT's for the residential apartments the rest of the way up.

 

I think CLT's are a fantastic material to work with. It's a cross lamination of approximately 1" solid wood in 3 or more layers. Each layer is perpendicular to the preceding layer. It's plywood made of solid 6" wide strips. Its very strong and can be made in very large pieces depending on the plant capability. Often a CLT will be  wall height by 16 to 20'. 

After the panel is laminated together, it goes to a machining center in the plant such as a Hundegger. Here the panel is cut to size, window and door opening are cut, and if planned, the plumbing and wire chases are machined into the face of the panel. Once completed, its set by crane at the job site.

 This building is being built to the Minergy Code. It's the minimum energy code in used Switzerland. A project will not receive an occupancy permit without meeting it. The highlights are design requirements that minimize thermal bridges, Have high insulation values, and an airtight (1.2 ACH) envelop.

Here you can see what the insulation plan is. A small amount of pink EPS and lots and lots of Rock Wool. Although I was not able to verify it, it appears that the EPS was going to be used in ground contact and the rock wool all above grade. In this region common practice is to apply the rockwool to the exterior of the CLT panels with long screws similar to SIP screws but with a much larger shank for vertical loads. Making an entire layer of 6+ inches of rock wool is the thermal break you typically see in CLT construction.

Next posing will be thermally broken stair case, air sealing, timber framed roof and  the bio mass system.

A day of learning in Switzerland

I spent today learning about vapor diffusion, convection and air sealing at the company SIGA near Lucern Switzerland.

I have to say... I have a few weekness: to name a few it's timberframe buildings, good beer and being in a beautiful setting. Today had all three in one: I'm used to good beer and am regularly in beautiful settings, but I can't say that I've ever been in a manufacturing plant, complete with robotic packaging stations, that were all housed in a Timberframe. My TF Guild friends would be proud.

The class at Siga was insightful and filled the day with a really interesting subject still new to most of the US: how to build airtight without creating a breading ground for mold spores. I can't say that I ever thought I'd look forward to spending a day on that subject, but things change.:)

Happily, I got to spend some time with a PH Consultant from Latvia. It was interesting to hear that PH is gaining ground steadily in the Balitic region. He was here to take in all he can on airsealing for the same reason as me... 0.6 ACH. It's great to meet people from other parts in the world walking the same trail at the same time.