Contributed by Jason Spangler
For years now, the in situ relative humidity (RH) test for measuring the moisture condition of concrete has been shown to be the most reliable, accurate test available.
As far back as the 1960s, laboratories at the Portland Cement Association conducted controlled tests that verified the accuracy of RH testing. This research was followed by years of additional testing at Lund University in Sweden and elsewhere. In 2002, ASTM International first established the F2170 standard for conducting RH tests on concrete slabs.
The research confirmed two key discoveries:
Other methods typically involve taking measurements only at the surface of the slab. As the research has found, a surface-based moisture test can’t provide an accurate measure of a slab’s true moisture condition. That’s because it doesn’t account for the moisture conditions deeper within the slab, and those conditions are typically quite different than conditions at the surface.
The Standard Evolves as the Science Tells Us More
The initial ASTM F2170 for in situ RH testing was established in 2002, after continuing research at Scandinavian universities in the 1990s identified the exact specifications for conducting a reliably accurate RH test—placing the test probe at 40 percent depth for slabs poured on grade or 20 percent for slabs drying from both sides. After these scientifically-validated specifications were firmly established, ASTM International published a usable standard.
Until now, the ASTM F2170 standard has required a 72-hour waiting period between drilling the test holes where the RH probes are placed and taking official RH measurements. In practice, readings are often taken before the 72 hours has passed, so contractors have an idea of how things are trending. But because the official readings couldn’t be taken before 72 hours, that meant all decisions and work were basically on hold for those three days. Full stop.
Yet we’ve seen how the research on the RH test method has helped to refine our understanding of how best to use it. This trend continues. In 2014, a Precision and Bias (P&B) study, commissioned by the ASTM committee, tested for differences in RH readings at various intervals within the 72-hour period. In part, the idea was to assess if it is actually necessary to wait the full 72 hours for an accurate, actionable moisture readings.
Contributed by Janis Kent, FAIA, CASp
Lavatories have some of the more involved clearances, below which impact reach ranges above. The question of why is this important to understand might be arising in your thoughts. The answer is the impact on the location of faucet controls, soap dispensers, and any other built-in items including electrical outlets and switches.
The knee clearance under a lavatory is 27” minimum height above the finished floor (AFF) extending horizontally from the front edge to a depth of 8”. If you are working in California, the height clearance tapers from the front edge at 29” AFF, down to 27” AFF at 8” back. The next portion of the knee clearance is tapered from 27” minimum AFF down to 9” minimum AFF at 11” back. The toe clearance requires an additional 6” horizontally beyond the bottom of this taper. This is nothing new, but what we often lose sight of, is this taper is at a rate of 1” depth for every 6” of height – a total of a 3” depth beyond the full 27” clear height. You can increase the depth at the lower portion of the taper more than 3” but the toe clearance is still calculated as starting 3” back from the top of the taper. Another way of looking at this is the furthest point of the toe depth is an additional 9” back maximum from the start of the taper at 27” AFF.
For a lavatory with front approach, you need to remember that you cannot reach beyond your toes. So, if you have the minimum of 8” at the top + 3” of taper (the typical 11” minimum depth requirement) + 6” for your toes, this totals 17”. If this is the furthest your toes can go, the faucets and soap dispenser (if fixed) have to have their controls located within reach range. So, 17” maximum from the front edge of the lavatory counter or fixture.
Contributed by Randy Nishimura
A cozy group gathered at the Eugene Builders Exchange this past Thursday for the May chapter meeting of the Construction Specifications Institute-Willamette Valley Chapter. The topic for the meeting was repurposedMATERIALS, the successful enterprise at the vanguard of the rapidly growing materials repurposing industry.
CSI-WVC member Alorie Mayer, who has a background in energy and resource conservation management, organized the presentation of a webinar by repurposedMATERIALS president Damon Carson. Damon founded the company in 2011, and it has only grown by leaps and bounds since then. In Damon’s words, repurposing occupies the intersection of affordability and sustainability. The repurposedMATERIALS business model involves taking byproducts out of the waste stream and extending their maximum practical benefit while minimizing waste and the expenditure of new energy to ready them for new uses.
Damon introduced the topic of repurposing materials by having us think about what many of us did naturally as preschoolers: taking an empty Quaker Oats canister and transforming it into a drum or a container for Lego blocks, or reimagining a Maytag refrigerator shipping box as a medieval fort or a space-age rocket. This, in his words, was our “substitutionary thinking” at work. Repurposing isn’t a new concept; fundamentally, it is an innately human behavior.
Damon cited the waste hierarchy pyramid and how reuse occupies a perch near its peak. Repurposing is not the same as recycling, which typically involves energy-intensive processing of the materials (e.g. chipping, shredding, grinding, or melting) before reuse is possible. Repurposing is a means to extract the maximum practical benefit from products while minimizing the cost to the environment. As a waste-management strategy, repurposing minimizes emissions of greenhouse gases, reduces pollutants, saves energy, conserves resources, creates jobs, and stimulates the development of green technologies. Repurposing rather than reprocessing previously-used items also saves time and money, making quality products available to people and organizations who may be of limited means.
Of course, repurposing isn't a new concept. Artists (like my friend and former co-worker Rosie Nice) have long fashioned sculptures and other works out of what most people would consider junk. Habitat for Humanity ReStores and Eugene/Springfield’s own BRING Recycling sell salvaged materials but tend to emphasize reuse rather than repurposing. For example, salvaged doors or windows sold by Habitat for Humanity ReStores or BRING are typically used by the purchasers for the same ends they originally were originally intended for. What distinguishes repurposedMATERIALS is its procurement of large amounts of discarded products no longer suitable for their original purposes but are otherwise practical for altogether different uses.
Contributed by Emily Conner
American’s spend more than 90% of their lives indoors. The majority of those daytime hours are set inside the office walls. Despite the rise of e-commerce and remote workers, most businesses still operate out of traditional, energy-hogging buildings.
Collectively, our country’s building stock accounts for almost half of our annual total energy usage, 3/4s of our electricity consumption, and pumps out more than 39% of CO2 emissions produced in the U.S. The World Economic Forum also reports that the Engineering & Construction (E&C) industry is the nation’s single largest consumer of raw materials like steel. The Environmental and Energy Study Institute (EESI) predicts that, conservatively, by 2025 energy use in the business sector will cost more than $430 billion – about the same as our annual Medicare spend.
Businesses have a major opportunity to reduce their environmental impact. Where do they begin? Easy. A better-built environment starts with a more sustainable building sector. We’ve collected some climate-friendly ways to make a positive contribution.
But first, some quick business.
Potential CO2 and Energy Savings
The lifespan of an average building is 50-100 years. During that time, they produce tons of CO2 emissions every day. With new construction breaking records every year, we have the ability to make huge gains regarding energy efficiency.
As ESSI points out, “If half of new commercial buildings were built to use 50% less energy, it would save over 6 million metric tons of CO2 annually for the life of the buildings—the equivalent of taking more than 1 million cars off the road every year.”
So, there it is. Problem solved, right? New builds for everyone and our climate is saved? We think taking a more realistic course is a better plan of action.
Building Better with Sustainable Solutions
Let’s face it, not every business can afford to erect an entirely new LEED-certified green building and still have money to operate out of it. But there are ways businesses and construction companies both large and small can help transform the built environment.
Though this list is by no means comprehensive, here are seven moves that can inch us toward a better-built building stock.
Contributed by Al Eini
The Basics: Maintain Aesthetics, Ensure Safety
Life safety and egress are critical considerations in every building so it comes as no surprise that panic devices play a significant role in the design and installation of entrance systems. Panic devices come in several styles for various door types. With all-glass entrances growing in popularity, however, tubular panic devices are being specified more frequently, particularly in high-end applications. These elegant systems offer maximum transparency and a contemporary look.
Although panic hardware is nothing new, tubular panics and glass doors present unique challenges. For example, all of the mechanics of a standard panic need to be concealed in a sleeker, more attractive design while meeting safety standards. Issues with glass templates and sizing, and hardware compatibility can arise.
For successful tubular panic handle and glass door installations, key hardware and overall entrance design considerations must be taken into account, as well as specification criteria that will ensure door openings comply with life safety codes. Overcoming the challenges associated with tubular panics will lead to safe and secure all-glass entrances that meet the design intent.
First, Know the Code
Both the International Building Code (IBC) and NFPA 101 – Life Safety Code require panic devices to be listed in accordance with UL 305 – Standard for Panic Hardware. The Builders Hardware Manufacturers Association (BHMA) also has its own standard for panic hardware: ANSI/BHMA A156.3 – Exit Devices.
IBC and NFPA 101 panic device requirements apply to most jurisdictions. According to the IBC, panic devices are required on doors when Assembly Occupancies have a load of 50 or more people; Educational Occupancies have a load of 50 or more people; and when High Hazard Occupancies have any occupant load.
NFPA 101 requires panic devices on doors where Assembly Occupancies have a load of 100 or more people; Educational Occupancies have a load of 100 or more people; Day Care Occupancies have a load of 100 or more people; and where High Hazard Occupancies have a load of 5 or more people.
Other key code requirements include:
Be aware that there are often exceptions, and every jurisdiction adopts specific code requirements for panic hardware. That’s why it’s very important to consult the Authority Having Jurisdiction early on in the project. Failing to do so can lead to compliance issues, which translates to costly and time-consuming reworks.
Let's Fix Construction is an avenue to offer creative solutions, separate myths from facts and erase misconceptions about the architecture, engineering and construction (AEC) industry.
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