Foundation + Waterproofing Material
For the base foundation, we used 24 x 14 insulated blocks, also called ICFs. These Nexcem foundation blocks, originated from Switzerland, are made up of wood chips rather than styrofoam or plastic. This product is a benefit to our overall eco-friendly design because they are made out of 75% recycled products, moisture resistant and energy-efficient.
In order to protect our foundation, we applied three layers of waterproofing material to help prevent damage and future decay. The first layer being an acrylic tar, on top of that we applied a dimple drain sheet, and lastly we installed a French drain that will help gather the excess water and drain it away from the house towards the backyard.
Open Truss Joists
Our decision to go with open truss joists was to achieve long spans all while keeping a flat ceiling surface. They allow running cables, wires, and pipes through the ceilings. That also benefits our plumbers and HVAC contractors, because they provide extra space to install pipes and materials without damaging structural elements. TJI® joists help maintain continuity of interior insulation.
For the exterior insulation package we installed 6 inches of insulation, which consists of the three different types. The first line of defense is a waterproofing membrane called SIGA Majvest 500. On top of that, around the entire house, we installed a 3 inch wood fiber insulation called GUTEX Multitherm® 80. Since this particular material cannot receive stucco, we had added a third layer of insulation called rockwool comfort-board. GUTEX Multitherm® is made up of 95% wood fiber and has zero carbon footprint. The manufacturer reduces carbon dioxide from the atmosphere and it is put into this specific material. By adding a waterproof paraffin wax as a protective coating, the product can be exposed to weather elements for up to four months, which is beneficial for building in the winter/spring.
Roof Design + Materials
The idea behind this roof was to completely air seal the house, to prevent any elements from entering or escaping the structure. In order to do so, we completed framing of the house, then added an insulation layer onto the roof deck. On top of that we installed 2×6 LVLs and used that for our 3 foot roof overhangs on around the whole structure. In a cross pattern with the LVLs, we installed ledger boards, and on top of that we installed aluminum sheet metal. The benefits to aluminum sheet metal roof is: 1. energy efficiency, 2. ease of installation, 3. great to overlay with solar panels, 4. Longevity
HVAC + ERV System
When you make a super insulated house it is important to add appropriate heating, cooling and ventilation systems. The HVAC system we used in this house is a continuous ventilation system from Zehnder. This machine has three inch tubes that scatter throughout every room of the house and mixes, filters, and conditions the air from each room. Another term for this machine is called Energy Recovery Ventilation (ERV) system. It takes the moist, stale air from rooms like kitchens, bathrooms and laundry rooms, filters it and feeds the fresh air back to the rest of the house 24 hours a day.
The HVAC system consists of an Electric Air Handler SVZ by Mitsubishi. One is located in the basement and the second one in the attic. This particular model gave us the flexibility to use it anywhere in the house. The unit functions even if it is turned 90 degrees and even if it is used horizontally. It can fit in small confined spaces. Using two units, give us the ability to supply fresh cool and hot air throughout all three floors of the house.
In addition to the 6 inches of exterior insulation, it was important to add the best interior insulation package for extra protection. We utilized closed cell spray foam between the rafters to prevent any moisture accumulation from the underside of the roof. The rest of the cavities are filled with blown-in cellulose insulation. The overall insulation package will provide us R-values of R-60 on the roof and R-40 within the walls.
Floor Warming System
This floor warming system by Schluter® called DITRA-HEAT, allows us to place heating cables all around the kitchen in places we will need it most. We are then able to install tile over the uncoupling membrane without any bumps, helping create a smooth level ground. The free space underneath DITRA helps provide water vapor to escape effectively, all while warming the tiles to help withstand the cold winter months.
Shower Waterproofing System
This lightweight Schluter Kerdi shower kit includes components that are perfect to help waterproof, not only your shower but the entire bathroom. Made up of extruded polystyrene, this package helps create a watertight assembly and is great to use as an extra layer of interior insulation. We continued it onto the base of the curbless shower, so there is a smooth transition from the shower to the bathroom floor without any barriers. All while creating a vapor tight assembly from floor to ceiling of each bathroom.