Category Archives: Environment

Impact of Water and Climate When Talking About CLT

Cross-Laminated Timber (CLT) is the trendy new building material that has received a lot of attention in the northwest this year.  It is by definition a series of thick boards (usually 2×4 or 2×6) glued together in an alternating pattern and Cross-to form a solid wall, post or beam. (A similar concept is glue laminated (glue lam) timber that has been used for beam construction for many years.)

To understand how water affects wood construction, one must understand its function in a tree. Wood is designed to provide structural support for the tree, move water from roots to leaves and store the chemical results of photosynthesis (primarily sugars in the form of cellulose). These properties of wood create some challenges for its longevity when exposed to moisture.  Thus, while wood can be structurally strong, it naturally absorbs and retains water.

Depending on climatic conditions, it can take some time for CLT panels to fully dry after getting wet. So, moisture control is of utmost importance when building from wood, such as cross-laminated timber.

The first source of moisture concern is during manufacturing. While manufacturers try to have all of their boards have the same moisture content, wood is an organic material and each board reacts to moisture differently. Some take water in more quickly and some take longer to dry. The result is that boards swell and shrink at differing rates which can affect the performance of a CLT panel.

Think of the hardwood floors in older buildings where the floor buckles in places. That is what happens when one board expands against another. As the wood dries again, it shrinks. This expansion and contraction process can damage the wood causing new cracks and gaps. On a floor, one can just refinish it. But, CLT is an integrated structural component and any deformity can weaken its life-safety purposes.

Another source of moisture is environmental moisture during construction. Studies indicate that construction moisture wetting is a serious problem in rainy climates like the Pacific Northwest. It can take several years for the wood to fully dry after construction. With rainfall likely in any month of the year, it is vital that proper precautions be taken to prevent the wood from getting and staying wet.

It is not just rainfall that is a concern. Other sources of moisture must also be accounted for, such as sprinklers, groundwater, pressure washing of siding, sidewalks, driveways, etc. decorative ponds, swimming pools, or other sources of moisture.

Wet CLT panels built with wrappings that do not allow vapor to pass through (both interior and exterior) are much more likely to develop bio-deterioration. There are vapor permeable wrapping on the market that can mitigate this concern to some extent.

Exterior cladding also plays a significant role in preventing moisture penetration. Not long ago, there were significant problems with wood frame buildings experience the negative effects of prolonged moisture, especially condominiums. The resulting lawsuits bankrupted many developers and contractors. With CLT, the stakes are even higher. With wood frame, the walls can be exposed, dried and cleaned. Since CLT is a structural system, that process is much more difficult and expensive.

In comparison, concrete, masonry and block all dry very quickly when wetted. Any remaining moisture can be removed easily (similar to using your shop-vac and a floor-squeegee in your garage after a big rain). Thus, construction moisture is of much less concern. And, there is no concern with rot with concrete, masonry and block construction.

One solution is to cover the CLT panels during construction until they are clad with the exterior components (be it siding, brick or stone). This is complicated, expensive and time consuming. Thus, covering panels during construction can undermine the presumed time and cost savings of CLT construction.

Another possible solution is to install water and air barrier membranes when the panels are manufactured. To date, no manufacturer is doing this, presumably because it would be cost prohibitive.

Certainly, more research needs to be done before the public can be assured of the safety and environmental impacts of cross-laminated timber panels used in construction. Also, new additional building code standards and construction practices would need to be developed to mitigate the health, life-safety and structural concerns posed by our wet climate on CLT buildings.  Current building codes allow wood structures to be built up to five stories. The talk is some would like to go up to as many as 20 stories with CLT.

The risk of fire in a wood building has historically been the primary concern with high-rise wood construction, but, water and climatic conditions can have an equally and perhaps more insidious impact on the construction.

CLT may have the potential to be a sustainable building product that lowers the carbon impact of building.  But so do proven products like concrete, steel and masonry.

While fire is an immediate and known risk, water’s impact is subtler, but no less threatening. This is particularly true in the Northwest from the Pacific Coast to the Cascades.

MBA staff cleans up Bellevue park


Last Friday, staff from the Master Builders Association of King and Snohomish Counties spent a good part of the day clearing trails, spreading ground cover and performing light yard work at the Mercer Slough Nature Park in Bellevue.

It’s not the first time the MBA has improved the park. In 2009 the builders’ association completed Wet Lab 2 at the park’s Environmental Education Center as part of its centennial year celebration. The 5-Star Built Green lab is used by the Pacific Science Center to teach kids about the environment.

Last week’s work is part of the MBA’s ongoing volunteer work to better the community.

Way to go guys!

Proposed rule expands Clean Water Act jurisdiction

AGC of America reports that the Environmental Protection Agency (EPA) and US Army Corps of Engineers (USACE) proposed their new rule aimed at clarifying the definition of “waters of the U.S.” and which bodies of water fall under federal jurisdiction. This definition is critical to many of the Clean Water Act programs affecting how contractors perform their work, such as the Section 404 Dredge and Fill Permits, Section 402 Stormwater programs, and Section 311 Spill Prevention, Control, and Countermeasures plans.

At this point, the proposed rule appears substantially similar to a previously leaked version, a massive – and unnecessary – expansion in Clean Water Act jurisdiction. Ditches, ephemeral and intermittent streams, tributaries, and isolated waters located in a floodplain or riparian area (which have no defined limit in the rule) are all now potentially jurisdictional.

The rule is expected to be published in the Federal Register soon, with a 90-day comment period in effect after publication.

L&I doing the home show circuit

The Department of Labor & Industries will have a booth at 18 home shows this winter/spring throughout the state to inform homeowners about hiring the right construction contractors.

L&I says home show attendees in search of a contractor should arrive with a plan that includes:

• Know what you want. Whether planning to update your bathroom or build a fence, write a list of the features you must have versus the features you’d like to have. Bring magazine pictures of desired features.
• Talk to a variety of vendors and contractors. Bring a list of questions about your project and ask contractors about their experience.
• Confirm prospective contractors are registered with the state at Registered contractors must have a business license and a current certificate of liability insurance and a bond on file with L&I, providing some recourse if the project goes bad. Just because contractors have a booth doesn’t mean they’re registered.

The first event, the Tacoma Home & Garden Show, is running until Sunday inside the Tacoma Dome. Admission is $12.

Low carbon fuel standard could negatively affect construction

Washington State is considering the implementation of a low-carbon fuel standard (LCFS). While some of the effects of such a policy on the construction industry are unknown because it has yet to be tried anywhere, the things that are known about the policy are not good.

The push for a low-carbon fuel standard is coming from two directions: The Governor’s Climate Legislative Executive Workgroup (CLEW) will soon be making its recommendations for greenhouse gas-fighting policies the state could adopt, and the LCFS is one getting serious consideration. Plus, Governor Inslee signed a pact with other western states and British Columbia that promises to enact greenhouse gas policies regionally, including a LCFS. Neither of these actions actually creates new policies; they are more suggestions of what the state could do regarding greenhouse gases. In any event, these are strong indications of upcoming legislative battles.

The draft CLEW report talks about implementing a LCFS of a 10% reduction in the carbon intensity of the fuel mix over a 10 year time period in the State of Washington. It doesn’t prescribe what the fuel mix will be; just that it should have lower carbon intensity.

Keep in mind that for years refineries have been making fuel with 10% ethanol for many markets. But, even a 10% ethanol mix reduces the fuel’s carbon intensity by only 1%. Adding even more ethanol (and it would take a lot more!) has been shown to dissolve seals and gaskets in engines. Fuels with something else – such as agricultural waste products – has never been developed in the mixes needed to reach the 10% carbon intensity reduction.

So without a real-world test, it’s hard to say what the affect would be of a not-yet-developed fuel mixture on construction equipment and vehicles. But as AGC’s Oregon-Columbia Chapter pointed out in battling a similar proposal in Oregon, converting to higher biofuel content fuels would affect truck engine warranties. Currently, there are percentage limits on blended fuels, which when exceeded will void many manufacturers’ warranties. It is very likely that construction equipment and vehicles would have to at least be retrofitted to accommodate blended fuels, as was the case for recent clean air rules and their impact on older diesel-powered equipment.

Other concerns raised about LCFS proposals include:

  • Limited supply of biofuels in the US would likely trigger fuel shortages and spikes in fuel production costs, and industry analysts forecast that fuel costs could go up by as much as $1-$1.50 per gallon as a result.
  • Retro-fitting equipment to handle these biofuel blends is incredibly expensive. The majority of contractors would be faced with making changes they cannot afford, while only some contractors are able to make the necessary investments in biofuels/energy production technologies, onsite fueling depots, total fleet conversions and all of the costs associated with these capabilities.
  • California’s Low Carbon Fuel Standard Program was ruled unconstitutional in a United States District Court based on the Interstate Commerce Clause.  The court battle continues.
  • This kind of program is not feasible at the state level- these policies should be a matter of discussion at the Federal level. In fact, there are already federal mandates in place for advanced biofuels technology through the Federal Renewable Fuel Standards (RFS) program.

Crank out green kilowatts with wind turbines

The following post is by Liz Nelson :

When it comes to renewable energy sources, the first two that are predominately on the minds of many is the use of solar panels and wind turbines. For wind turbines, the principle is the same that you see in every gasoline guzzling car. Each of those vehicles are using an alternator to turn torque power into electric current to charge the battery. The wind turbine is no different. It is using the wind to turn the generator to produce large amounts of electricity in the same fashion as the automobile – minus the gas guzzling engine.

Depending on the area you live in, the wind may be constantly blowing. As there may be no resistance to hold the wind back, it is free to blow. Home-based wind turbines don’t have to stand at 200-feet in order to harness some of the wind that is blowing. As long as there is a deep cycle battery connected, any amount of wind could help reduce your energy expenses and could possibly remove your dependence from the grid. What are some of the features that are tied in to a wind turbine for residential and business locales?

1. Sizes – Various sizes are available for wind turbines, so you don’t have to assume it’s going to stand 200-feet tall with blades longer than your house. In fact, there are smaller units that can produce up to three kilowatts of energy from wind speeds of approximately 25 miles per hour that can fit in your garage next to your car. Devices like the Aleko WG3KW has a security feature that will throttle itself back at speeds of 40 mph in order to prevent damage from overcharge or burning the motor out.

2. Inexpensive – Compared to other renewable energy developments, wind power can be less expensive to produce similar results. For less than $2,000, you can assemble the small Aleko unit featured above and cover a large portion of your energy needs. Typically, a large family home could utilize 5,000 to 7,000 kilowatts of power requiring a few of these devices. However, the cost for implementing solar could be four to five times that amount if you installed it yourself.

3. Zero Emissions – The only source required by a wind turbine to generate power is wind. As there are no consumable fuels going into power generation, there are no emissions. The generator is simply powered by the wind spinning the blades of the unit. Although skeptics may point out that there are emissions being created by the vehicles used to ship the items, the point is moot. Unlike coal and oil based power plants, there are no other fuels being consumed to create energy. Tens of thousands of tons of coal are shipped annually to various power plants.

4. Combined Efforts – If you discover that a single unit isn’t supplying the power you need, additional units can be erected and tied into your power. This allows you to purchase turbines as you need them and not have to worry about coming up with a lot of money in order to be energy efficient.

Renewable energy sources are being developed and utilized all over the globe. What was once thought as a passing fancy has turned into a quest for continued efficiency. Whether you are a household of five or need to supply power to your business, wind turbines can offer an affordable solution to help reduce your bills and help conserve energy from the grid for other uses.

Liz Nelson of is a freelance writer and blogger from Houston. She can be reached at

House Passes Coal Ash Bill

By a vote of 265-155 the U.S. House of Representatives recently passed HR 2218, Coal Residuals Reuse and Management Act of 2013, which prevents the Environmental Protection Agency (EPA) from designating fly ash and other coal ash residuals from being classified as a hazardous waste. The legislation, introduced by Rep. David McKinley (R-W.Va.), establishes a regulatory structure for coal ash that would be controlled by states with little EPA oversight. The White House released a statement this week expressing its concerns about the bill and suggesting improvements, but did not threaten a
veto. A similar bill is pending in the Senate.

Preventing EPA from taking action to deem fly ash as hazardous has been a priority for many in the construction industry. AGC of America submitted detailed comments to EPA urging that it weigh the potential impacts of its regulatory options on the beneficial use of these materials and take into consideration the real environmental benefits of reusing these materials and the lack of negative reports (i.e., alleged or proven damage cases) associated with the beneficial use of fly ash in many construction applications including concrete and wallboard. AGC urged EPA to either rely on state requirements or establish non-hazardous waste requirements that protect the beneficial use of fly ash in construction.

Members of the Washington Congressional delegation who voted “yes” were Reps. Hastings, McMorris Rodgers and Reichert.  Those voting “no” were Reps. DelBene, Heck, Kilmer, Larsen, McDermott and Smith.


Greenfire flames environmental passion

While Bullitt Center is grabbing headlines as the greenest commercial building in the world, a project in Ballard is taking green building a step further by dedicating about half of its site to urban gardens and open space.

The DJC is profiling the Greenfire Campus project in a special section.

Greenfire’s office building will use about 70 percent less energy than a typical office, and its apartments will use 42 percent less. All that urban agriculture will be fed by two cisterns that store stormwater runoff.

Expect to see more projects like this in the future.

One sweet hard hat

Pittsburgh-based safety equipment manufacturer MSA has come up with a way to make hard hats greener — it uses sugar.

While it sounds like construction workers would be in for a sticky mess after that first rainstorm hits, that’s not the case. MSA developed the hats in Brazil using high-density polyethylene sourced from sugarcane.

“By developing a hard hat sourced from sugar, we have reduced the overall carbon footprint that’s associated with the entire life-cycle of this particular product, from start to finish,” said Eric Beck, MSA’s global director of strategic marketing, in a release.

The “green” polyethylene is made from sugarcane ethanol, which results in a smaller carbon footprint because, for each ton of the material produced, up to 2.5 pounds of carbon dioxide are captured from the atmosphere. Conversely, Beck said one ton of polyethylene sourced from petrochemicals emits more than 2 pounds of carbon dioxide into the atmosphere.

The final kicker is that green polyethylene is 100 percent recyclable.

MSA claims the hats are the first industrial safety product produced from nearly 100 percent renewable resources. I wonder if the U.S. Green Building Council has LEED points for that.

For more information, check out

Water factor flows in construction

Handling water and wastewater is becoming more and more important in our everyday lives. Just take a look at the DJC’s Environmental Outlook special section and you will see several articles on the subject.
First up, read about how Ecology is revising Sediment Management Standards to clarify what is needed to clean up contaminated sediment sites and to make the cleanup process more effective. Then read about the 200 West Pump and Treat System at Hanford that is scrubbing contaminated groundwater while saving more than 70 percent in energy costs over its life.
Not all water management is about getting stormwater out of the ground. Arnie Sugar from HWA GeoSciences writes about the benefits of increased infiltration of stormwater using low-impact development methods.
Then there’s wastewater. Tom Paul of Mortenson Construction covers how wastewater plants can be tapped as a renewable energy source.
If all this water talk has your head swimming, you can read about proposed rules that would allow some larger projects to bypass the SEPA process.

Thanks to all who participated in the special section!