At Eco Supply we believe Passive House building techniques are an important part of the ongoing efforts to solve the energy crisis. Buildings consume more energy than any other sector, accounting for approximately 75% of energy produced, and nearly half of CO2 emissions. Passive House building envelop techniques offer a simple and elegant way to reduce these numbers. We are proud to be expanding our product solutions to support the home building industry.
Can you spot the passive house in the thermal image below?
A real manufacturer is not just an assembler, an even more important distinction when it comes to wood windows. Making your own profile blanks and controlling the quality is critical. Having the level of skill it takes to make those blanks and understanding the vagaries of wood and how the laminated blanks should behave produces much better end results. Bildau goes as far as sustainably harvesting their own Siberian Larch, the wood processed at their own sawmill in Russia.Request a Catalog Learn More
Passive house requires a lot of insulation and adding an exterior layer often helps in this goal. This often means foam over the sheathing. Foam is vapor closed so in our freeze thaw and wet environment in the Mid-Atlantic and Northeast this can be a problem. Placing a vapor barrier on the outside of the building can trap water and vapor inside. Although our cork isn’t as permeable as a weather membrane, water vapor can move through it with about the same ease as plywood unlike foam. The cork isn’t subject to UV and heat degradation or the same expansion and contraction issues that foam has. It handles these elements well enough that was have a slightly denser version that can be fully exposed, adding a façade and insulation in one step. You are also choosing an all-natural, compostable, recyclable, carbon negative product made from just cork that has no adhesives versus polystyrene. After seeing a butane torch put to the self-extinguishing cork versus foam, it’s very apparent that fire code standards are built around foam versus truly being focused on our safety.Get Samples Learn More
For passive house projects air sealing is paramount and although not difficult or expensive since you already need an envelope, it requires a good bit of attention and a good system. Really any new construction and also renovation can benefit from improved air sealing and the vapor control that goes with it. 40% or more of the energy lost from buildings can come in the form of air leakage. There is a steep curve of diminishing returns from adding more insulation if air sealing is neglected. Cold air leaking in doesn’t need to suck out much energy, causing the HVAC to kick on due to the low specific heat of air. The air is heated by the HVAC and then cooled by the leaks and the cycled repeats. Adding insulation won’t be as effective as getting a decent air seal in this case.
Luckily the cost to air seal properly adds little to the bill of materials on a typical building envelope and sheathing package. It’s accomplished with more careful planning and the right materials and system. Our products are also flexible, allowing builders to build the way they want to build but also meet new air tightness requirements without having to use a specific system. Windows, building wraps and integrated components like Zip-system often come with tape. These tapes are obviously an afterthought, made by a second party and seen as nothing more than a cost to the manufacturer when they should be of primary concern. Without a long lasting seal at joints and seams the efficacy of their wonderful components is compromised.
We often see solvent based adhesive tape in the building industry. The adhesive often attacks substrates and always gets more brittle over time. This adhesive is certainly attacking the skin of the tape as well. Adding to the problem is the vapor closed nature of these tapes. Right at the point of typical water intrusion is a mass of vapor closed tape. The framing material cannot dry out thus causing moisture to build up behind the tape surface at the adhesion point. A tape that allows the components to dry is very important. SIGA tape solves all these problems since it is a purpose built line of tapes, with specific products and form factors for different applications.
Although you need to be careful since the tape is so sticky, SIGA will stick to a wider variety of materials over a wider range of temperatures. Getting tape to stick to cold masonry, and cold or hot metal can be a real bugaboo, but not with Wigluv and the Dockskin primer for cold concrete/brick. SIGA Wigluv comes in a variety of widths and split back configurations to speed install. Its flexible and stretchy nature allows for less on-site frustrating origami and time consuming cutting. The tape surface or carrier sheet can be flexible since the proprietary adhesive is also flexible and very thick. Take a closer look at it and you’ll see that Wigluv is unlike anything you’ve used previously.
Another benefit of the vapor open natural of Wigluv is the ability of primer or adhesive to cure from below the tape after it’s been sealed in. The same thing that allows the building to dry out where Wigluv is used compared to normal tapes also allows the Docskin primer and surface treatments to dry. The best example of this issue is bonding the weather barrier to foundations. A sill plate with some foam on either side will not cut it when it comes to good air sealing. This area moves and the foam gets brittle. With SIGA dockskin primer, one person can paint on this adhesive primer to stubborn masonry while another follows immediately behind taping the WRB to the foundation, bridging the gap between the sheathing and the foundation or masonry. With the zip system, just the wider 100mm, 150mm or 230mm Wigluv tapes can be used to join the zip panels to the foundation or make up for the inevitable gaps in the sill seal.
SIGA Majvest (My-vest) weather barrier wrap is a very high performing wrap at a very low price. At $0.30 a square foot is very inexpensive and the quality is much higher than Tyvek or Typar. The material is three plys of solid fabric material not just a substrate web and coating. The Majest WRB is a very vapor open but air tight barrier, shedding all bulk water but allowing trapped vapor to exit the building. A heavier duty version is available to roof applications.
SIGA has an interior line of tapes and a vapor closed membrane for super high performance homes in the Northeast or very cold climates. Placing the vapor closed membrane far on the inside just behind the sheetrock forces vapor in the wall cavity out through the Majvest to the outside. It also keeps warm, humid, conditioned air on the inside so it doesn’t leak into the cold walls, condensing on studs and structural components. Their Corvum 12/48 split backed tape for the inside of window frame to wall joints makes this a full system for permanent air and vapor tightness. Foam may or not work initially but it is not a permanent solution.
SIGA’s system is a great high performance air and weather tight system for a great price that is easy to apply. We have a complete, simple system from the foundation to the roof.Learn More