Investing in Insulation

Hello and welcome to Local Fruit Folsom. This week’s blog is about insulation and the building envelope. Throughout our new construction home project the focus has been energy efficiency. We chose to invest in building a quality envelope around our living area because our goal is to minimize our utility bills and try to get to a net $0 in annual utility bills.

 

Soy-based closed cell spray foam in exterior walls



After using advanced framing to maximize the energy efficiency from a structural and framing basis, we selected highly efficient windows and turned our focus on the insulation of the building envelope. The objective is to build a very efficient home and use a solar PV system to minimize the actual purchase of utility power. When focusing on energy efficiency, the absolute most important element in the design of the home is the insulation.

 

Open cell foam under the roof deck



We attended Greenbuild in 2009 in Phoenix and saw a demo of a hybrid system at the CertainTeed exhibit. Seeing an actual demo structure allowed us to better understand what we were asking of our builder in 2010, and of our insulation subcontractor in 2011. Learning about the envelope and advanced framing also helped us to choose a quality builder who had experience with green building techniques.



Our house is constructed using four different types of insulation:



• Roof deck - 8” of open cell spray foam to achieve R30



• Exterior walls - both closed cell soy-based foam and blown cellulose to achieve R27



• Floor – Fiberglass batts



The house was framed using 24” x 6” on center advanced framing. This means that the framing is 24” apart and the exterior walls are 6” deep to allow for very thorough access during the insulation phase. There is not an exterior surface that is not extremely well insulated. In the walls, we decided to go with a hybrid system that includes 2” of closed cell foam and 4” of blown cellulose. Closed cell foam has many advantages but is extremely expensive compared to open cell foam or cellulose. By using only 2” of the closed cell foam we gain the benefits of a tight seal, added structural rigidity and improved wind resistance for the home. Closed cell foam is made from soy beans and does not allow water or air to pass and it is mold and pest proof. However, when reviewing costs it became evident that 6” of foam does not deliver as much R-Value per dollar as a combination of insulation methods.

 

Quite a few of the contractors wanted to be involved in a green project, but lacked actual experience. We chose Gai Kirkegaard to build our home because he had already built a LEED Platinum home in our town: he talked the talk and walked the walk. He even drives one of the most efficient cars available-proof that he lives efficiently. When talking about the envelope or advanced framing, Gai and his team truly understand the intricacies of green building.

This week was exciting as both the roof and insulation were installed. The insulation installers make a terrible mess, but as soon as they clean up we can schedule the insulation inspection. After that drywall starts and we can start counting down the weeks until we get to move in. Whoo-hoo!





Lumber Mold

House with siding and shingles

Hello and welcome to Local Fruit. It has been a few weeks since I last posted an update on the construction of our home. Although framing and trim have taken longer than we expected, the project is moving along quickly now!

The siding shingles and trim are almost completed, as are rough plumbing and rough electrical. This week’s short blog is about an incredible process to protect and preserve the wooden members of a construction project using a corn product that also cleans the wood beautifully.

 

Mold stain on framing



Lumber Yard Molds



When framing in the winter, like we did, lumber comes to the job site from the lumber yard in a variety of conditions ranging from damp to slightly discolored (lumber yard mold). Depending on how much exposure the wood has had to rain and the sugar content of the wood, the lumber yard mold may range in color from green/blue to grey to black. In our case, the house and apartment were framed during a very long rainy season. Here is a photo of the lumber yard mold in the apartment structure. After questioning the builder about the growth in the wood, we decided to get an independent test of the wood just in case there were spores that were dangerous. After all, only a tape test analyzed by a qualified (certified) mold specialist can determine what species are present and make recommendations as to the removal of the growth.

 

Corn cleaning product


The tape test confirmed the presence of lumber yard mold in the apartment and in several areas in the main house. After speaking with our builder, we decided to remediate the condition using a company that follows a two-step process to treat all exposed wood: remove the growths using high pressure blast of corn fractions (like corn meal) and then apply a weak borate solution. Both steps are completely natural and chemical free, contain zero VOC’s and improve air quality after use. But this is why we chose to proceed: the end product is a clean structure at a reasonable cost.



Corn fractions after cleaning



  

Corn fractions up close

 



Borate Solution - 100% natural



After power blasting the wood, the team used air pressure to blow out all dust and debris from the house. Then they applied the borate solution which is claimed to prevent mold, mildew, moss, fungi, termites, etc. The remediation company, MoldGaurd USA, Inc. backs up their marketing claims with a guarantee against future growth.

The very green process is used in commercial multi-family construction projects to reduce both cleaning costs and liability of future mold growth. The before and after photos on their web site are very convincing and in our case the house was spotless when the team left. Unfortunately the electrician and HVAC guys came in the next day and made fresh sawdust… more for us to sweep each day.

 

Our builder, Gai Kirkegaard Construction, is calling for the framing inspection this week, and insulation installation next week. The heart of this house is the envelope, with efficient windows, clean walls and great insulation. The next posting should be about out insulation and our application to the California Advanced Homes Partnership for energy incentives.