Category Archives: Building Structure

The truth about soy-based insulation

Q: I heard that there is spray foam insulation that is made out of soy rather than petroleum.

Is this available anywhere in Fairbanks and does it work well?

One of the latest advances in spray foam insulation is a partial soy-based insulation. However, “soy-based” can be misleading, as the “petrochemical-based” is more accurate.

Spray foam works by combining two components, commonly referred to as the A & B components. The Acomponent is a diisocyanate (a petrochemical), which is mixed on a one-to-one ratio with the B-component that can contain modified natural or petroleum-based oils. In order to get the chemical reaction to work, the proportion of natural ingredients cannot be too high. Spray polyurethane foams can approach 40 percent natural oil, such as soy or canola oil. The total mixture, when foamed, is likely to be on the order of 20 percent to 40 percent natural oil content, depending on the recipe.

In terms of its effectiveness, the spray foam provides an R-value that is as high — or sometimes higher — than foam that do not contain soy. Spray foams are also measured in their resistance to water absorption, called a “permeability rating.” The rating of spray foam that contains soy is comparable to foam that does not contain soy.

In Fairbanks, there are spray foam installers that use soy in foam. Contact a local spray foam business for additional information.

Reflective Insulation-not a big help in cold climate construction

adding an aluminum facer to a 1-inch piece of EPS (expanded polystyrene)

CCHRC has just released a report on the effectiveness of reflective insulation in a cold climate. The insulation, which has a reflective surface, is commonly used in hot climates to reflect heat from the sun away from a building. For example, a home in Florida could add it to the roof decking to divert heat from the attic insulation and save on air conditioning.

But our researchers found that the insulation is less effective in a cold climate because it doesn’t add much r-value to an already well-insulated building.

Check out the full report here

Energy rebate program is still alive in Alaska

Q: I signed up for the home rebate program months ago and haven’t heard from anyone since. Has the program ended or are the energy raters just really busy?

When you signed up for the rebate program, you put your name on a waitlist.

Your name will be given to an energy rater when funding becomes available for you to participate in the program.

Then your assigned energy rater will call you to set up an appointment for your energy rating.

So the rebate program hasn’t ended, but all the funding has been set aside for other program participants. Funding becomes available for new participants when others let their deadline pass without collecting their rebate. You can check your status on the waitlist by visiting or by calling 1-877-257-3228.

Once there is funding available for your rebate, an energy rater will call you to set up an appointment. When the rater performs your rating, be sure to keep your receipt. You will need to send it, along with a copy of the rating, proof that you own your house and Alaska Housing Finance Corporation’s (AHFC) As-Is Energy Rating Reimbursement form to AHFC.

It is important to mail these documents as soon as possible to ensure that funding is set aside for your rebate.

Q: I have a lot of moisture and ice building up on my windows, especially when it is really cold. Are my windows bad?

Not necessarily. Single-pane windows are prone to icing up if with even the smallest amount of humidity inside a home.

These windows are not recommended for this climate. Double and triple pane windows with icing problems can be a sign of a broken pane or broken window seal.

Also, the home may not be getting adequate ventilation, which causes condensation on windows when indoor moisture levels increase.

This column has focused on winter indoor air quality several times over the past year. To read our past advice on this topic, visit our website at

Alaska HomeWise articles promote awareness of home-related issues. If you have a question, e-mail the Cold Climate Housing Research Center at can also call the CCHRC at (907) 457-3454

Gaps in Alaska law mean ‘buyer beware’ when it comes to household mold

From The Fairbanks Daily News-Miner, Monday, November 8, 2010:

The new owners of a North Pole home were renovating the guest bedroom when they discovered black mold festering along the base of a wall.

Their real estate agent pointed them to someone who could help.

In mid-October, air quality consultant Bill Reynolds peeled back a layer of paint that had been applied over the mold.

Air samples from the room revealed Stachybotrys (pronounced stacky-bottress) levels of 5,200 spores per cubic meter. The environmental laboratory considers anything more than 600 “of concern,” Reynolds said.

The water, which came from a leaky bathtub pipe next door, soaked the trim along the wall and provided both ingredients for growing mold: moisture and cellulose.

“We were just really disappointed because it was not disclosed in the papers,” said Tanja Glidden, the new homeowner, who is eight months pregnant.

School renovation is a lesson plan for Weller Elementary students

From The Fairbanks Daily News-Miner, Tuesday, October 26, 2010:

The students at Weller Elementary School initially had mixed emotions about the renewable energy project in their backyard because it caused some trees to be cleared outside their windows. But they seemed to have come around by last Thursday, when engineer Robbin Garber-Slaght gave an interactive presentation to about 100 fifth and sixth graders on the ins and outs of the ground source heat pump and solar thermal system installed in September.

“I learned that it was worth it to destroy the trees,” said fifth grader Chase Wagner. “It will help the school be green. I’m worried about the planet. It will cut down on oil and it will save money.”

Students showed their impressive knowledge of energy efficiency and power generation, as dozens of hands waved in the air to offer thoughts and ask questions in the school’s common area.

“That was a really fun group. They’re up on their science,” said Garber-Slaght of the Cold Climate Housing Research Center, which collaborated with the school district and other contractors on the experimental project.

Respiratory illness rates high in rural Alaska

From The Associated Press, Saturday, October 23, 2010:

Researchers say rural Alaskans and Alaska Natives are more likely to develop respiratory illnesses than anyone else in Alaska.

The Tundra Drums reports that Centers for Disease Control and Prevention researcher Rosalyn Singleton says rural Alaskans contract respiratory illnesses in part because they live in crowded conditions through harsh winters that leave residents indoors for long stretches of time.

Singleton says many rural Alaska homes lack running water, making hand-washing difficult. She says wood-burning stoves and smoking indoors contributes to the level of respiratory illness, as do dusty clouds that sweep off roads.

Despite the difficult conditions, hospitalization rates for children suffering from respiratory illness on the Yukon-Kuskokwim Delta are falling.

Free class on cold-climate building to be offered in Bethel

From The Tundra Drums, Friday, October 14, 2010:

A free class will be offered in conjunction with Bethel’s second annual energy fair.

The Advanced Cold Climate Building Techniques will take place Oct. 28 and 29, from 8:30 a.m. to 5:30 p.m. in room 118 at UAF’s Kuskokwim University Campus in Bethel.

For those who wish to earn CEUs, or Continuing Education Units, the cost is $45. This class gives licensed builders and construction folks a residential certification. (This is a $480 class in Anchorage.)

Continue reading: University offers free class on cold-climate building

Don’t forget the proper foundation insulation

By CCHRC Staff

The “Ask a Builder” series is dedicated to answering some of the many questions Fairbanks residents have about building, energy and the many other parts of home life.

Q: How do I insulate my foundation and how much is enough?

Insulating a foundation is an important step in both retaining heat during the winter and reducing heating costs. Concrete or concrete block — the material used to build most Alaska home foundations — is very conductive. If not insulated, it will transfer heat from a crawlspace or basement directly to the surrounding soils or outside air. Many Fairbanks homes, especially older homes, do not have insulated foundations. Putting insulation on the outside of the foundation will slow that heat transfer and ultimately save energy and money.

The most commonly used insulation for new homes and when retrofitting older homes is rigid foam board that is rated for below-grade application. If an insulation is rated for below grade, that means it is less susceptible to water absorption and is not damaged as easily.

Another option is to hire a professional to apply spray foam to the foundation, which has similar insulative and water resistant capabilities.

Building code requires that new homes have R-15 of insulation installed on a foundation. That amount is equivalent to about 3 inches of rigid foam board. Insulation should be applied to the outside of the foundation all the way down to the footer.

Spray or foam board can also be applied to the interior foundation or crawlspace walls. This method saves effort because the entire perimeter of the home does not need to be dug out; the down side is that this method consumes interior living space.

Be sure that any interior insulation is either fire rated or is covered with a fire rated surface.

Q: I have wastewater pipes that have recently become frozen. How should I thaw them out?

Frozen wastewater can cause backups that can lead to a messy situation.

Heat tape will slowly thaw frozen pipes, but could require months of thawing.

There are ground-thawing machines that can be rented, but they are often difficult to use. The safest option would be to hire a professional to thaw the areas that need work.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at can also call the CCHRC at (907) 457-3454.

In-ground heat pumps require some expertise


By CCHRC Staff

The “Ask a Builder” series is dedicated to answering some of the many questions Fairbanks residents have about building, energy and the many other parts of home life.

Q: Recently I read the News-Miner story about the heat pump being installed at Weller Elementary School. Are there different ways to install this type of system and is this something I can do myself?

Ground source heat pumps operate in a way similar to how a refrigerator transfers heat out of an insulated box to the surrounding air of your kitchen. In this case, the heat pump absorbs heat from the ground and transfers it to a home. The heat exchange mechanism between the ground and the heat pump is typically a series of liquid-filled tubes.

There are different methods to get the heat out of the ground each of which require different installation needs.

One system is the shallow horizontal trench, which is being used at Weller Elementary.

In this configuration, the tubes are made into overlapping loops and placed approximately 10 feet in the ground. For people who live in areas of shallow ground water, it is beneficial to get the loop below the ground water table. This requires a large area, so this type of system is probably not feasible in a downtown lot, but would work well on a southsloping hillside with a lot of land available.

Another option to consider is drilling multiple wells.

These would be similar to drilling a drinking water well for a home, except that only the heat in the water is being extracted, not the groundwater itself. It is likely that more than one well would be needed to heat a house.

The third option is to sink the ground loops deep into a body of water such as a pond or lake, provided that the water body is sufficiently large to accommodate the heat demand. Contact the Alaska Department of Environmental Conservation before beginning this type of project.

All of these options are for a “closed-loop” system, where freeze-protected fluid is circulated in a closed system of piping. There are also “open-loop” systems that draw ground water directly and then inject the water back into the ground.

In most cases these are not appropriate for use in Interior Alaska.

In terms of a do-it-yourself project (and Alaskans are pretty handy) a heat pump involves digging a deep well or large trench, which will probably require hiring a driller or excavator. The equipment that makes up a heat pump is technical. Hiring someone who has been certified by the manufacturer or by the International Ground Source Heat Pump Association to install these systems is recommended.

Contact local heat pump distributors to get more information on installation.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at can also call the CCHRC at (907) 457-3454.

Elementary school tests heating technology novel to Interior Alaska

From The Fairbanks Daily News-Miner, Friday, September 17, 2010:

Large rolls of black tubing sat like super-sized balls of yarn next to the playground outside Weller Elementary School Wednesday. The sun shined brightly on the south-facing hillside, where a bulldozer carved out a 12-foot hole.

The balls, which are actually polyethylene ground loops, were then rolled out and buried in the ditch, where they will harvest heat from underground to use in the school during the winter. In the summer, six solar thermal panels soon to be mounted on the school will replenish heat to the earth through the same tubes. The system will not only reap savings on heat for the school district but also will test a technology that is young in Fairbanks.

“I would like to see a system that would work well in the Interior and that the public can utilize and save dollars,” said Larry Morris, projects manager for the Fairbanks North Star Borough School District.

The project is an experiment to see how well the systems work in tandem and to collect data on ground source heat pumps, which are common in the Lower 48 but rare in Fairbanks.

“What we’re trying to do here is pair that system with a solar system that will recharge the heat you take out of the ground. In warmer climates, the sun can recharge how much you take out,” said Aaron Sirois, an engineer for PDC Engineering. “We were trying to come up with a solution that’s kind of adapted to Fairbanks.”