Category Archives: Building Structure

Driftwood cabins the next government housing in Emmonak?

From The Tundra Drums, Wednesday, July 7, 2010:

The “river loggers” who float driftwood down the Yukon River for heating have a new use for their big bundles: a seafood company that hopes to show housing agencies it can build low-cost homes with local materials.

The Yukon Delta Fisheries Development Association buys the logs and last year turned some into a supply store where fishermen can buy nets and other gear.

Now it’s building a demonstration cabin down the road in Emmonak, a Yup’ik village of 800 that sees logs float past regularly, many uprooted by ice boulders and floods that scour the banks each spring.

Continue reading: Driftwood cabins the next government housing in Emmonak?

Housing researchers look for the best way to keep Interior Alaska walls dry

From The Fairbanks Daily News-Miner, Monday, June 5, 2010:

Everyone in Fairbanks knows summer is when the ground thaws and your bones warm. But it’s also the season when your walls dry by shedding moisture deposited in the wall cavity during the winter. When walls warm in the sun, built-up water vapor wants to go back outside where there’s less moisture.

“The way we build walls controls how much that happens,” said Colin Craven, product testing director at the Cold Climate Housing Research Center. “You want your walls to be able to breathe one way or the other.”

Today, many homeowners add outer foam-board insulation to their houses to save energy, but the extra layer can trap moisture inside the walls, causing mold and decay.

“We always thought, ‘Should we really do this?’ It seems to be working, but there’s no real data besides ‘We haven’t seen houses fall down yet,’” said Terry Duszynski, a Fairbanks energy rater who helped jump start the project.

This summer, the research center is completing a yearlong test of how various wall systems handle moisture in Alaska climates to avoid this type of problem.

Time to get all decked out


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: What are my options for eco-friendly decking?

In today’s market, the selection of decking materials is vast and can be overwhelming.

Other than wood or treated wood — which have been traditional materials for years — there now exists a wide variety of composites which may contain a combination of synthetic materials.

Composite decking is typically comprised of some type of plastic or vinyl, and in addition, some brands also will also use ingredients derived from wood products. When it comes to treated woods, the chemicals used in the treatment process have gotten more eco-friendly than the chromium copper arsenate (CCA) which dominated the industry for many years. Be aware that the new treatments tend to be more corrosive to metal fasteners, so today’s treated woods may require a specific type of treated connector in order to insure that the deck will hold together safely in the long term.

Composite decking may contain recycled plastic and/or recycled wood fragments. Some brands may even be composed almost entirely of reclaimed products. Common recycled ingredients include old pallets, mill waste, plastic shopping bags, bottles, and other discarded plastics. One of the primary advantages of composite decking is it requires little or no maintenance. Not all composites can span the same distances between joists as wood decking, and so may require additional framing for support.

Most local lumber yards will carry both wood and composite decking. A good resource which compares decking and other products is the website

The site has lots of information on a number of different building materials.

Q: I have a heat recovery ventilator in my crawlspace, and it’s starting to make funny noises, what should I do?

HRV systems require routine maintenance, and if the maintenance schedule is ignored it can severely impact performance.

For regular maintenance, examine the filters, outside hoods and screens for cleaning or replacement every one to three months. Filters can become clogged with organic debris including insects, pollen or dust and grass, especially if the fresh air intake is close to the ground.

Most of these filters are washable.

The exchanger core also needs regular maintenance. It should be inspected approximately every six months and cleaned as necessary. The core can be vacuumed or washed with soap and water depending on the situation, so refer to the owner’s manual for specifics. Also, be sure to examine the condensate drain, and if needed, clean it at the same time. The lines can be tested by slowly pouring water into the drains to check for obstructions.

The HRV drains should have a trap or a loop containing water, which will prevent the unit from drawing in air through the line.

Testing the lines is important because the HRV is sometimes tied into a septic line for drainage, or is located in a crawl space with other plumbing. Consequently, if there is a problem with the drain, the HRV system may suffer the ill effects.

Also, fans need to be checked every three to six months. Many fans are designed to function without lubrication, but some HRV fans require it, especially the older models.

Another important point is to make sure the HRV is “balanced.” That means it should be taking in roughly as much air as it is exhausting so as not to create pressure problems in the house. If you are not sure that the system has ever been professionally balanced, this is definitely a step worth taking to insure the system is operating properly.

Most manuals will contain information regarding maintenance specific to that particular brand and model of HRV. If you have lost yours, typically there are only a few different brands in Fairbanks and those manuals are usually available online.

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.

State readies borrowing program for green projects

From The Fairbanks Daily News-Miner, Thursday, July 1, 2010:

The state is readying a new borrowing program that some municipal governments have shown an interest in tapping to improve energy-efficiency at public buildings.

The Alaska Housing Finance Corp. said the program — an account for governments and the university system to borrow for energy-efficiency remodeling — should open by October. The corporation is collecting public comment through July 7 on regulations behind the plan, a spinoff from a federal stimulus grant that would model broader programs seen around the country.

“We don’t have to reinvent the wheel,” said Bryan Butcher, a spokesman for the housing corporation, citing successful precedent elsewhere. “We think it’s really going to play a substantial role in reducing energy (costs) in the state as well as producing jobs.”

The Lowdown on Bamboo Flooring

From Mother Earth News:

Bamboo flooring is increasingly popular as a green building material. Stalks can be harvested sustainably, and bamboo floors are as tough as they are beautiful.

Bamboo flooring is constructed in two basic ways. Solid bamboo flooring is composed entirely of layers of bamboo. Engineered bamboo flooring consists of a top layer of bamboo with a backing made of wood. There’s nothing necessarily wrong with engineered flooring. In fact, it can be more appropriate for some installations. In addition, bamboo flooring comes in two configurations, which differ in how the bamboo strips are laminated together: either in flat, horizontal strips, or in thin vertical layers set on edge.

Continue reading: The Lowdown on Bamboo Flooring

UAF researchers work on way to ease road-building costs in rural Alaska

From The Fairbanks Daily News-Miner, Sunday, June 27, 2010:

A possible remedy to rural Alaska’s enormous road construction costs might be sitting in a grimy plastic bin at the University of Alaska Fairbanks.

Billy Connor sifted through the bin’s contents with his hand, digging through material that looks like it came from a badly abused sandbox. There was lots of silt and sand, some thin plastic fibers and a sticky fluid that smelled like latex paint.

Connor, the director of the Alaska University Transportation Center, thinks this messy combination holds promise as a rural road of the future. It’s roughly three times stronger than silt alone and able to withstand pressures of about 175 pounds per square inch in laboratory tests. It also appears to be resistant to the freeze-thaw cycles that cause roads to buckle in permafrost-laden areas.

“We think we can cut the construction costs at least in half, maybe even more,” Connor said.

One Family’s Green Backyard Playhouse

From Mother Earth News:

For years, I dreamed of building my own home using natural materials. But time passed, and I started to think about what I could do with the house I actually owned and lived in. In the end, I carried a shovel and some hand tools into the backyard of my vinyl-sided split-level ranch, and started building a cob house — an elflike playhouse for my children.

What took shape was a small cottage built of stone, cob (clay and straw) and wood, much of it gathered on-site. It took far too long to build, and demanded an endless supply of sand and clay. But the process was pleasant and rewarding. The structure emerged organically, dictated as much by available materials as the shape of our small city lot. A grove of hemlocks at the edge of the property provided an idyllic setting; however, the steep pitch and rocky soil presented challenges for excavation. As difficult as this was, the digging yielded enough stone for a rubble trench and a mortared foundation. It also produced good clay that went into the walls, plus contributed the material for the attached wood-fired pizza oven.

Recycled timbers formed a post-and-beam frame covered with a steep gabled roof. Walls of 6-inchthick cob went up slowly, molding around salvaged windows. The cob was mixed on tarps, stomped and squished by the small bare feet of my two daughters and the neighborhood children. Poppy, my 3-year-old, was especially good at screening clumps of dried clay. Ella, at 8, drilled holes with a masonry bit in 100-year-old slate shingles.

Continue Reading: One Family’s Green Backyard Playhouse

Insulating your foundation with ease


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: I have a concrete foundation. I heard insulating your foundation can save heat. How can I do that?

Concrete is very conductive, and heat always goes to cold, so a foundation without insulation is basically a bottomless heat sink. If the foundation is un-insulated, there are definitely opportunities to save some heat.

Current code requires an R-value of 15, which is about 3 inches of blue foam.

Ideally, digging out the outside of the foundation and insulating the outside will keep the foundation warmer but doing this type of work on the outside of a home is not always practical. In such a situation, put foam on the interior of the home’s outside walls and tape the joints.

On a similar point, the rim joist area is prone to air leakage where the joists meet the outside wall.

Often, fiberglass insulation is put into joist bays, but that is not enough to stop air leakage. A better choice is to install sheets of foam fitted to each joist bay, then spray foam around the edges.

Another option is to hire a spray foam contractor to spray between the joists.

These techniques will help stop air flow and heat loss through that part of the foundation.

Q: Is there a way to limit the amount of offgassing in my home or ventilate it in some way?

For those who do not know the term, offgassing, or outgassing, is the release of gas from materials over time. Often these materials are plastics or other petroleum-based substances that release chemicals that can be hazardous to health.

For starters, try to use “green” materials that do not offgas hazardous substances like formaldehyde and other volatile organic compounds (VOCs). Low VOC and non-VOC paints, carpets, caulks and glues are available. Furniture and fabrics also offgas, so look for healthy alternatives such as solid wood furniture and other non­VOC products. In new construction, despite the best attempts to use entirely healthy products, there will probably be some type of VOC. Before moving in to a new home, ventilate the home as much as possible. One method is to turn the thermostat up very high, to promote outgassing, and run the ventilation system at high speed for a day or two. This tactic will help “bake out” and vent VOCs.

In older homes, particleboard countertops, shelving and cabinets can be coated with a non-VOC sealant to prevent further outgassing.

Also, use greener cleaning products and store chemicals outside rather than indoors. Try to purchase only as much as needed so unused chemicals do not sit around.

The best way to get rid of offgassed substances is to regularly make sure the home is properly ventilated by opening windows and using mechanical ventilation.

A well-ventilated home will exchange air more frequently, exhaust pollutants and bring in fresh air.

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.

Replacing your windows, all panes at a time


By CCHRC Staff

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

Q: What is the relationship between boilers and combustion air?

Any appliance that expels air must have its own air supply or one appliance could be drawing air through another. When a boiler expels gas out its flue, an equal amount of make-up air must be brought in. Similarly, any appliance that sends air out of the house needs to be supplied with intake air. If an appliance is not supplied with intake air, it may pull the air it needs down through the boiler’s chimney, thus “backdrafting” the boiler and pushing combustion gasses into your home.

For example, in a “tight” home (one with sound insulation and well-sealed doors and windows), where a wood stove and a boiler both draw air, the boiler may get its air supply by backdrafting the wood stove. However, if you have provided adequate air supplies for both appliances, both should operate with no problems.

Q: If one of the panes in my double or triplepane window breaks, can I get the pane replaced, or do I need to replace the whole window?

When one of the panes in a double or triple pane window breaks, all of the glass layers must be removed and replaced.

Taking apart a window also involves removing several parts such as the “stop” which holds the glass in place, the jamb liner, and other components.

Typically the frame and any associated trim can remain untouched. Virtually all factory- built vinyl, fiberglass, and wood windows have provisions for removing the glass.

If the window can open, simply disconnect the opening portion from the frame and take it to a glass shop.

Repairing a “fixed” or “picture” window can be more complicated. Wood windows may use screws and be relatively easy to replace, however removing the glass from vinyl or fiberglass units is less obvious. In many cases, this involves a “snap in” type window stop located either on the inside or the outside of the window, separate from the main portion of the frame.

Generally, this type of repair is best left to professionals, since removing the stops can be difficult and can result in more broken glass.

Sometimes the window stop will be adhered to the frame with two-sided glazing tape or adhesive caulking.

The replacement glass not only needs to be the proper length and width, but also the proper thickness and space between the panes. If a glass shop replaces the glass, they will provide a guarantee, which in itself is worth piece of mind.

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.

Know the soil under your home


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: My home is on a postand- pad foundation because I live on spongy ground. I notice some changes in the floor in my home over the winter and summer each year. Is there anything I can do to prevent this?

Most Fairbanks homes using post-and-pad construction were built in anticipation of some degree of seasonal movement or in an attempt to cope with ground instability because of permafrost.

A home’s foundation changes with the seasons as the soils underneath the pads expand and contract in reaction to yearly freeze-thaw cycles. For example, entry doors may consistently stick all winter, and then work fine in the summers, year after year. This can happen regardless of whether your home is situated on permafrost or not.

The layer of ground directly under a home that freezes and thaws with the seasons is called the active layer. In some cases, the active layer can extend down 10 feet or more depending on the types of soils and seasonal conditions. Autumns with heavy rain followed by cold winters with little snowfall particularly affect soils, sometimes creating what is known as a “frost heave.” For this to happen, soils have to be of a fine enough particle size to trap or “wick” water and enough moisture must be present to cause the soil to expand when it freezes.

Unfortunately, much of Interior Alaska is covered with fine silts which tend to drain poorly and can expand aggressively if they contain too much water when winter hits.

Removing these soils and replacing them with non-frost susceptible material is typically unrealistic for an existing house.

However, there are a few relatively minor improvements, which can help curb the severity of the problem. Good site drainage can make a big difference. The ground should be sloped away from the post-andpad foundation, and large roof overhangs with gutters will help divert water away as well.

The downspouts on the gutters should extend along the ground horizontally to divert water away from the pads and soil that bears weight.

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.