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Parking garages in this region are attacked by road salts and water throughout much of the year. The cost to repair deteriorated concrete can be quite high and the project can cause significant inconvenience to garage users. So, as part of a parking garage restoration project, we recommend and our clients tend to include, application of a vehicular-traffic-bearing membrane on the structural slabs to help protect their investment and extend the service life of the garage.
There are two basic classes of products commonly used to protect garage slabs, one of which is penetrating sealers. Penetrating sealers include materials such as silanes and siloxanes, which are silicone-based water repellants. These compounds penetrate into the concrete and react with the silica to create a water repellant barrier that also retards chloride migration.
Penetrating sealers are breathable so they do not create a vapor barrier and are relatively inexpensive. However, they do not seal cracks and require frequent reapplication as their effectiveness decreases with wear and time. These materials usually need to be renewed on a three to five year schedule.
The other class is traffic-bearing membranes, which are liquid-applied materials in several layers of cementitious, epoxy, or urethane compounds. These systems are all relatively thick (up to about 90 mils) and are designed with the properties needed to withstand the destructive forces imposed by vehicles tires.
Incomplete combustion of wood in fireplaces creates a buildup of flammable oils (creosote) in chimney flues, which can contribute to chimney or building fires. Only dry, seasoned wood (preferably hardwood) should be burned in fireplaces. Green and/or water saturated wood burns at a lower temperature and less completely than dry, seasoned wood and poses a greater potential for creosote deposition. Coniferous woods (pine, fir, spruce, etc.) should not be used. They tend to be highly resinous and will deposit more material than hardwoods. Household trash or other items should never be burned in fireplaces.
Artificial logs should only be used in accordance with manufacturers’ instructions and limitations. Most such products are intended to be burned only one at a time. Artificial logs vary in composition from hardwood fibers (sawdust or other sawmill waste) combined with wax or other binders, to petroleum wax (paraffin) mixed with various recycled materials. As a general rule, artificial logs should not be used unless the composition and burning characteristics of a specific product are fully described and deemed acceptable. Plastics, unidentified composites, or other materials of questionable makeup should be avoided.
Fireboxes require occasional cleaning/removal of ashes. Ashes should only be removed when absolutely no embers are present. Because embers can remain undetected long after a fire is out, ashes should only be placed into fireproof, metal containers.
Chimneys should be periodically inspected and cleaned, the frequency of which depends on fireplace use. Annual inspection is recommended for fireplaces that are used regularly. Cleaning may not be necessary at every inspection interval. It should be noted that chemical cleaners (cleaning logs, fire additives, etc.) should not be considered equal to professional cleaning.
Some products incorporate catalytic chemicals that react with the creosote and cause it to soften, flake and debond; however, the dislodged material can accumulate on shelves or other chimney offsets. They also tend to react only with the outer layer of creosote and are only partly effective in the presence of heavy buildups. They also may have no appreciable effect on soot, or residue from artificial logs.
Some products (which employ copper or other metal salts) rely on the rapid expansion of gas created when the salts are burned to dislodge deposited material. The effectiveness of those products is questionable, particularly with respect to heavy accumulations.
Looking for that perfect employee gift this season? How about creating an enjoyable break room that will be used year-round.
Here is an example of space once confined by full height walls and only indoor lighting. Now, after adding frameless glass panels, it allows for natural daylight, as well as an open concept feel. A break room once used only for coffee cup refills, is now the center hub of the office.
Contact Shabbir Kazmi, AIA to discuss your break room needs.
Before any rope descent system (i.e., window washing boatswain chair) is used on a building, OSHA now requires that each anchor be identified, tested, certified, and maintained so it is capable of supporting at least 5,000 pounds in any direction.
Did all your anchors pass the test?
The OSHA set November 20, 2017 deadline for physical load testing of these anchors has passed. (29 CFR 1910.27(b)(1)(iii)).
Did you make the deadline?
We loaded anchors of many different configurations and found that not all anchors passed this stringent test. If you have any anchors that have not been subjected to this testing in the last 10 years, they must be load tested and certified by a qualified person before they are used. This regulation also seems to apply to new anchors that were installed after the November 20 deadline and not just older anchors.
Don’t postpone your scheduled winter or spring window washing work, get your anchors tested soon. Call us @ 410-312-4761 or 703-450-622o | email@example.com
On a recent project, we discovered a “scary” sight – an Exterior Insulation and Finish System (EIFS) that was not installed properly. The exposed wall revealed channelized white foam insulation, an inconsistently placed liquid waterproofing membrane applied on the sheathing, several different brands of materials, and incompatible asphaltic flashing to cover the building facade.
The manufacturer issued a warranty for a drainable system, but no weep holes were installed around the windows and doors to allow the water to drain. This cobbled together assembly is not only a problem for keeping the building watertight, but the warranty seems to be invalid.
This highlights the need for field inspections by Certified EIFS Inspectors (CEI) and installation by Certified EIFS Mechanics (CEM) and Contractors as designated by the AWCI (Association of the Wall and Ceiling Industry) to help ensure that the system is installed and performs as it was intended.
ETC and its employees are pleased to donate funds to Canine Companions for Independence throughout the year. This worthy organization provides assistance dogs free of charge to people with disabilities. We are proud to call CCI our designated charity. Learn more at cci.org.
Preservative (pressure) treated wood is among the most common materials used in the construction of retaining walls. Ground-contact rated is standard for that use, but a GC label doesn’t tell the entire story. The important factor is preservative retention – the amount of chemical that remains in the wood after treatment, usually expressed as pounds per cubic foot or PCF. Optimum levels vary with the chemicals used and some products considered suitable for ground contact have retention levels that are less than desirable for retaining walls.
The American Wood Protection Association (AWPA) lists three categories for ground contact use, General Use (UC4A), Heavy Duty (UC4B) and Extreme Duty (UC4C). Heavy Duty protection would be suitable for most circumstances. Extreme Duty would be appropriate in such locations as freshwater lake or pond side walls. AWPA has separate categories for use in marine (saltwater) environments.
The timbers most used in retaining walls measure six by six or eight by eight inches in cross section and full preservative saturation is difficult to achieve in material that thick. Consequently, the central portions are less protected and decay (rot) can occur deep within the wood before there’s any visible evidence of distress. So-called Ground-Contact-rated, forty-year timbers can experience advanced deterioration within as few as fifteen years, while appearing sound.
In order to truly evaluate timber retaining walls it’s often necessary to sample the material by extracting full-depth cores with a specialty bit. Usually, a simple visual examination is sufficient to determine the level of degradation. Sounding (with a hammer) can reveal advanced decay. Rot reduces wood to dust, which will produce a hollow sound if sufficient wood has been compromised.
Fall weather has revealed many areaways that have inadequate drainage because the drain grate clogs easily. It often takes just a leaf of two to slow down the flow on these small grates. Provide more margin against rising water and flooding interiors by installing larger drains. Not only will the larger drain remove water faster, it can become partially clogged and still have adequate flow to keep the water from entering under the door.
Thank you to our industry friends, Ev-Air Tight, Culbertson, Function Enterprises, CP&R,CWS, East Coast Building Services and Manganaro for participating in ETC’s mini-golf tournament. Your contributions helped raise funds for the Washington Chapter Canine Companions for Independence. The winner of the first-ever Canine Invitational Cup goes to….Ev-Air Tight!
Congratulations on winning the beautiful plastic trophy, as well as bragging rights of course!
Amid the 2017 hurricane season, we marvel at the images of the damage these forces of nature can inflict on our buildings and infrastructure. Wind speeds not only define the intensity of a tropical storm but also are one of the primary causes of damage to people and property. Taking a closer look at some of Maryland/Virginia/DC’s windiest hurricanes reveals just how significant Hurricanes Irma and Harvey were.
- 1954, Hurricane Hazel showed maximum sustained winds in Washington, DC, of 78 mph and maximum gusts of up to 90 mph.
- 1960, Hurricane Donna blew sustained winds in Maryland of 83 mph.
- 2003, Hurricane Isabel held maximum sustained winds of 58 mph and gusts of 78 mph in Maryland.
In September 2017, Irma touched down in Florida with sustained winds up to 115 mph and wind gusts up to 140 mph. Hurricane Harvey, in Texas, had similar wind speeds. These numbers are significantly higher than any tropical storm Maryland has experienced. By comparison, an even larger storm, Hurricane Andrew, overtook Florida in 1992 with peak winds at 164 mph and sustained winds at 142 mph.
The forces that hurricanes winds can apply to the structures around us is considered by structural engineers as we design buildings, renovations, and repairs. The infrequency of strong storms does not imply any insignificance to the designer, but rather the extreme forces that must be resisted. Building Code required design wind loads vary across regions of the United States based on the probable storm strength. In the D/M/V, we currently design to a wind speed of 115 mph and in Ocean City, Maryland the requirement is 130 mph for typical buildings. By comparison, Miami is in a 175 mph region and the Texas gulf coast is in a 150 mph zone.
More information on the history of damaging hurricanes, as well as the sources of the statistics in this entry, can be found in the following links.
Dust clouds created while mixing concrete, jackhammering or cutting concrete sidewalks, tuckpointing, and sawing masonry blocks will soon be a thing of the past. The Occupational Safety and Health Administration (OSHA) will begin enforcing new regulations concerning worker’s exposure to silica dust on September 23, 2017. Silica dust is commonly produced when working with concrete, brick mortar, tiles, cement board, and many other common building materials. Long term exposure to silica dust can lead to the development of lung cancer, silicosis, and other permanent conditions with long lasting consequences. Because silica dust is so prevalent, the new regulations will impact many different industries including many facets of construction. Complying with these regulations will potentially impact, property owners, engineers, contractors, and other individuals, in many ways including the cost of construction work.
While there are many requirements detailed in the regulations, contractors will have to offer medical examinations to high exposure workers, implement engineering controls for silica dust, and develop procedures to limit the exposure to silica dust that workers experience. Depending on the circumstances and activity, engineering controls can include a vacuum system with a 99% efficiency for certain cases or water methods of controlling dust. Additionally, a HEPA vacuum may be required in certain cases and a personal respiratory protection device must be supplied to workers.
Building owners, project managers, and other individuals involved with construction need to be aware of the impacts that these new requirements can have on projects. Additionally, contractors may require cooperation from building owners and managers to be able to adhere to the new requirements.
More information regarding the requirements can be found at: https://www.osha.gov/silica/
Wood construction is no longer constrained to low rise buildings and single-family homes. New uses are emerging resulting from an expanded interest in wood with new trends impacting construction. Tall wood construction has resulted in multiple high-rise wood buildings around the world from the 14 story Treet Building in Norway http://www.timberdesignandtechnology.com/treet-the-tallest-timber-framed-building-in-the-world/to the 18 story Brock Commons in Canada. http://journalofcommerce.com/Projects/News/2016/9/UBCs-Brock-Commons-rises-to-the-top-1018609W/
The interest in wood construction has led to office buildings, apartments, and commercial spaces being constructed out of wood. To support these structures, engineers have utilized advances in engineered lumber such as using glulam (glue-laminated timber), nail laminated timber, cross laminated timber, and other forms of engineered lumber. Engineered lumber is a strong wood based composite material that is often combined with special adhesives or other methods of fixation that can be used in columns, beams, and many other applications.
Renewed interest in mass timber has also risen because of the desire to construct tall wood framed buildings. It seems everything old is new again when you consider that the Old Faithful Inn was constructed in 1904 and is the largest log hotel in the world. The advances in wood engineering and higher levels of interest have resulted in investigations into potential changes to the building code that would allow taller wood construction. These trends indicate that the future of wood as a building material for both existing and new construction is exciting and filled with possibilities.