Category Archives: Wood

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.

Check out what’s happening in the local construction scene



The DJC has published its annual Construction & Equipment special section. It’s a mix of industry articles, profiles of local award-winning projects and a few interviews with the contractors who make it all happen.

Read all about it at


Huge apartment fire blamed on maintenance and light-weight wood



(This is the second fire at this complex since 2000 – while the project was under construction.)

EDGEWATER, N.J. (CBSNewYork) — Maintenance workers fixing a leak and using a torch is what started the massive fire at an Edgewater, N.J., apartment complex fire, officials said Thursday night.

As 1010 WINS’ Carol D’Auria reported, Edgewater police Chief William Skidmore said at a news conference the workers were using a blow-torch to make repairs to a leak at the Avalon at Edgewater complex, when a plumber accidentally ignited the fire in a wall.

Skidmore said the workers tried to put it out themselves and delayed calling for help for about 15 minutes. It is unclear how many workers were involved or where exactly the work was being done.

“They tried to suppress it themselves, and then they called their supervisor, which gave the fire a head start,” Skidmore said.

Fire Chief Thomas Jacobson said the delay in calling 911 put his crews at a disadvantage, WCBS 880’s Peter Haskell reported.

“It takes four minutes for a room to be fully engulfed and flash over so 15 minutes can make a big difference,” Jacobson said.

Officials also said Thursday a lightweight wood construction contributed to the fire, leaving hundreds of residents permanently displaced.

Edgewater Mayor Michael McPartland said a local state of emergency remains in effect due to the fire at The Avalon at Edgewater, which broke out around 4:30 p.m. Wednesday and raged for hours.

“It was a long and challenging night and I think every one of our first responders really stepped up to the challenge,” McPartland said.

McPartland said it was because of the good work of all the first responders that no lives were lost.

“I mean, I saw four brave men go into that fire and pull a woman out while the façade was coming down virtually on top of them,” he said.

The fire was brought under control by Thursday morning, but crews were still putting out hot spots and heavy smoke could be seen billowing from the structure even in the evening.

Jacobson said the fire appears to have started on the first floor and quickly spread through the floors and walls because of the building’s lightweight wood construction.

“If it was made out of concrete and cinder block, we wouldn’t have this problem,” he said, adding the building complied with construction codes.

Jacobson said the sprinklers were working and went off, but they were no match for these flames.

“It doesn’t get every area,” he said. “It gets the common areas where you can egress and get out. It gets your apartment. All the little voids inside every nook and cranny in the walls? No.”

Jacobson said crews simultaneously battled the fire while doing door-to-door searches and pulling people from the balconies.

“We had a crew trapped on the balcony with a victim; we had to rescue them with ground ladders from the back of the building. That was my concern first, not the building,” he said.

Firefighters from across New Jersey and from the FDNY helped battle the blaze. It was raised to more than five alarms Wednesday night and grew so large that the flames were visible from Midtown Manhattan.

As CBS2’s Sonia Rincon reported, the Bergen County Arson Squad investigated where and how the fire started, even though it later turned out to be accidental.

“A fire of this magnitude is an automatic response for the arson squad,” Skidmore said.

Schools were closed Thursday and will remain closed Friday. McPartland said access to some roads around the building would be restricted.

In all, 240 units were destroyed, permanently displacing about 500 residents, McPartland said. An additional 520 residents from other Avalon buildings have also been displaced, McPartland said.

“Don’t know where to even start,” resident Seoung Ju Won told CBS2’s Janelle Burrell.

“It was like a volcano eruption, really,” said resident Angela Nyagu. “That’s what I watched on TV before, how volcanoes erupt. Now I witnessed that myself.”

Among the residents of the complex was Yankees announcer John Sterling, who talked to CBS2 about his experience.

“I walked to the building and smelled smoke, and I went out to my floor where my apartment is, and the smoke was so bad I couldn’t see, and I thought, ‘Hey, we’d better get out of here,’” Sterling said.

And many residents, including Limor Yoskowitz-Frinomas, were still waiting to hear whether their homes were destroyed.

“We’re hoping for the best,” she said. “My kids are OK, so I’m OK, and we’ll take it from there.”

There were no reports of any missing persons, but McPartland said two civilians and two firefighters suffered minor injuries. He said some pets were rescued from the blaze, but some did die in the fire.

One woman told CBS2’s Meg Baker that her dogs were both killed.

“I saw gulfing flames coming out of the building, and unfortunately, I have two dogs that perished in the fire – Hailey and Griffin,” the woman said.

This isn’t the first time the very same apartment complex has been engulfed in flames.

In August of 2000, the complex was under construction when a fast-moving fire tore through it. The flames also destroyed a dozen surrounding homes, displacing up to 70 people.

The 2000 fire was ruled accidental by the Bergen County Prosecutor’s Office. No deaths or serious injuries were reported.

CMU Firewall Saves Multi-Family Structure from Disaster

photo 3A 50+ year old wood frame apartment complex in Airway Heights caught fire recently.

The structure is a dry wood frame, with a  CMU fire wall separating the building wings.  This building’s CMU fire wall prevented the adjoining wing from catching fire.  The front side of this structure received more damaged than the back which is shown in the photos.

This demonstrates the effectiveness of the CMU firewall component in multi-family and commercial structures.   The masonry industry works hard to continually reaffirm the use of CMU firewalls in buildings in condensed, urban areas to protect the community from major catastrophic fires as well as other energy, lifecycle and environmental factors.

The Masonry Institute of Washington is available to provide additional information on all masonry systems for both constructability and aesthetics.

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.

Historic renovation fair coming Saturday

Photo by Mary Randlett

Learn how it’s done from 28 historic building renovation experts on Saturday at the first ever Historic Seattle Renovation Fair.

The experts include architects, contractors, engineers, specialty trades people and suppliers. They will talk about remodeling older homes, earthquake retrofitting and historically appropriate window weatherization for old buildings.

The fair will be held 10 a.m. to 4 p.m. at Washington Hall, which is south of Seattle University at 153 14th Ave. Cost is $5 (free for Historic Seattle members). For more information, visit Historic Seattle.

If you can’t wait, Historic Seattle is holding a pre-fair event tonight at Rejuvenation Station, which makes and sells historic lighting and hardware reproductions. Tonight’s free event is 6-8 p.m. at 2910 First Ave. S. in Seattle.

Project breakdown start to finish, Insulation vs. ventilation

I would like to launch into a series of topics for discussion starting with foundations and working through each phase of a project to completion, but first to launch this endeavour I would like to do something to honor the current weather conditions and how it affects us. This is a sample of the topics to come, please feel free to submit any topic suggestions that you would like discussed during this series.

Attic ventilation and insulation is something most people never have much cause to think about, for single family and multifamily structures already completed there are ways to check if your attic is functioning properly, for new construction the same checks apply. Why is this important? 1. Heating & cooling loss = $$ out of your pocket 2. Damage can occur from ice damming and condensation 3.dry rot from insufficient venting. So what causes these issues? the concept of the conventional roof system is to insulate the ceiling (currently R-38 for attics is code) and vent the space above. Keeping the temperature of the attic close to the same temperature as the outside is very important.If the outside air is colder than the attic then cold air enters the attic through the improperly vented roof system it hits the warmer air and freezes any moisture in the warmer air. The other thing that happens is any metal (roofing nails, cast iron vent pipes etc.) that penetrate the roof into the attic do what is called thermal bridging, you may have seen something like this on aluminum windows where condensation freezes on the inside of the frames then melts creating a mess, roofing nails through the roof will rust and eventually allow water to leak in.

What’s the solution? first check to see what the depth of your insulation is, bat and blown in insulation is typically R-3.75 per inch so an 8″bat or blown in depth = R-30 which is pretty good! Next check to see all ventilation is in place and clear (sometimes the insulation blocks off the eve vents) next make sure there is an airflow pathway such as eves to gable end or ridge vents and that they are sized properly for the space (venting charts are available), this will keep our attics cold and living space warm in the winter with proper insulation. During the summer it works in reverse, hot air is ventilated out of the attic limiting the heat gain into our homes through our roofs while eliminating dry dry rot issues. In extreme cases the damage caused requires full roof replacement, climates definately play into the “extremes” however the solutions are the same, check with a local design professional or building inspector to see what is recommended for you region.

Matt Stodola

Beware of lacerating sanders

It reads like the latest slasher film from Wes Craven, but this one’s real. About 192,000 random orbit sanders made by Black & Decker can fly apart during use and possibly cut the operator. The company has received 73 reports of incidents stemming from the sanders’ black plastic platen discs breaking apart. Fifteen operators were injured.

B&D is doing a voluntary recall in cooperation with the U.S. Consumer Product Safety Commission.

The orange and black sanders are model numbers RO400, RO400G, RO410, RO410K, RO410LW and FS3000ROS, with date codes between 200701 and 200929. They were sold at home centers, hardware and discount stores nationwide from January 2007 to July 2009 for about 40 bucks.

Consumers should stop using the Chinese-made sanders and contact B&D for a replacement platen. B&D can be reached at (866) 220-1767 between 8 a.m. and 5 p.m. ET Monday through Friday; or on the Web at

Check out “tool library” coming to West Seattle

How many times have bought a special tool, only to use it once? Or, maybe you can’t afford a garage full of tools or don’t have space for them. Well, along comes a really cool idea — a tool library.

Folks at Sustainable West Seattle have been working for months on how to pull that off. Now, with the help of a $20,000  Seattle Department of Neighborhoods’ Neighborhood Matching Fund and other donations, the West Seattle Tool Library is slated to open on June 12 at South Seattle Community College.

The library will be more than a place to check out tools, it will offer classes and provide information on tool usage.

“So far we’ve partnered with organizations such as the West Seattle Nursery and Community Harvest of South Seattle, and have gathered tools from generous donors throughout West Seattle. Our biggest tool drive was held on May 8 at the West Seattle Community Garage Sale, which put our number of tools up over 300,” said coordinator Patrick Dunn of Sustainable West Seattle in a press release. “We’d like to encourage everyone to come out and join in the effort to provide community resources for West Seattle.”

The next tool drive will be held on June 5 at the Refresh Southwest festival. Tools can also be donated at the West Seattle Farmers’ Market and at South Seattle Community College. The library will be located at the college’s Garden Center, which is on the north end of campus at 6000 16th Ave. S.W.

Organizers are still looking for more tools (not gas-powered) and have put together a “wish list” that includes clamps, a pressure washer, portable table saw, portable planer, wet vacuum, wheelbarrows and more. Check out the full list: Tool Library Wish List.

DJC keeps construction workers busy

The Seattle Daily Journal of Commerce is finishing up a renovation of nearly 4,500 square feet of ground floor space in the Journal Building. Kudos to DJC publisher Phil Brown for keeping construction workers employed during these tough times!

Grevstad Construction of Seattle was in charge of the project, which included installing metal bracing and sandblasting the wooden ceiling, beams and columns for that great industrial-office look. A stairwell to the building’s basement was removed and a new stairwell connecting the mezzanine was added. New lighting, bathrooms, a kitchen and conference room were also added.

Finishing touches included new wall paint and a polished concrete floor. Lookin’ good!

The designers were Henry Walters and Carolyn Geise of Geise Architects.

Now all we need is a tenant. Starbucks? Contact Phil at (206) 622-8272 if you know someone who might be interested.