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Getting To Know the ETC Team #2
Pat Gray, R.S. | Senior Project Manager
10 things you didn’t know about me……
1.) I took dance lessons (including some ballet) between ages 4 and 12. They didn’t take.
2.) I ride Harley-Davidson motorcycles, to make up for all those dance lessons.
3.) I was voted “Mr. Selby-on-the-Bay” a long, long time ago.
4.) My favorite recording artists are Joni Mitchell and Eminem. Make of that what you will.
5.) I have no desire to know anything about a Honey Boo Boo, a Kardashion or a Real Housewife of anywhere.
6.) I love dogs, but prefer cats. They excrete where they’re supposed to.
7.) I think ”Lord of the Rings” is the greatest story ever published. Harry Potter is pretty cool too.
8.) I’ve never watched an Arnold Schwarzenegger or “Die Hard” movie.
9.) Playing “cops and robbers” as a kid, I was always a robber (more dance lesson backlash).
10.) I am not comfortable writing about myself.
Escaping the Hardship of Hardscapes
If you are contemplating laying a new concrete driveway or replacing an old asphalt parking lot, consider an environmentally friendly and potentially cost-saving option: permeable pavement. Traditional concrete and asphalt hardscapes are impervious, which means that storm water collects on the surface and runs to the storm drainage system. Standard hardscapes often lead to increased costs to install and maintain storm water management systems. They also create runoff which contributes to flooding and erosion. A green option such as permeable pavement allows a large portion of the rain water to drain through the material and filter into the ground below.
You may have heard of permeable pavement referred to by different name, including pervious pavement, porous pavement, or even popcorn pavement. Some of these pavements feature porous concrete or asphalt which literally allows water to drain through it via an interconnected system of voids. Other pavements feature a system of permeable pavers which allow water to travel through the material, as well as between the pavers. All these permeable hardscapes accomplish the same goals: helping the environment by reducing storm water runoff and helping your wallet by eliminating or reducing the need for retention ponds, underground retention tanks, swales, and other storm water management mechanisms.
There are just as many applications of permeable pavements as there are design considerations and limitations, so be sure to have a qualified professional discuss with you which options are best suited for your specific goals!
Getting To Know The ETC Team #1
Mindy Maronic, Director of Marketing
10 Things you didn’t know about me…
1. I love chocolate Pop-Tarts
2. I have jumped out of perfectly good airplanes…what was I thinking??
3. I suffer from a Diet Mt. Dew addiction. Zero days Dew sober, but I’m working on it.
4. I’m a huge fan of the Howard Stern show…although I DO have to turn him off at times.
5. My golf coach takes me to the section for “Serious Golfers Only” Who knew??
6. I’ve NEVER seen ONE Star Wars movie. Sci-fi people would hate me.
7. I’m scared of thunderstorm…..I often contemplate hiding under the bed with my dog.
8. Although I don’t wear them (yet), I LOVE people in stylish glasses!!!
9. I have never heard a county music song I’ve liked yet.
10. I enjoy doing kind things for other people. : )
No More “Fox Watching The Hen House”
Maryland Mold Remediation Services Act Beginning in July 2013, the State of Maryland will enforce The Maryland Mold Remediation Services Act, which will require all contractors that perform mold remediation on private homes (includes the interior, non-common areas, of Condominium units) must be licensed to perform mold remediation service by the Maryland Home Improvement Commission (MHIC). This is a different license than a typical contractors license. Additionally, each employee who provides mold remediation services must be properly certified as a microbial remediation technician or supervisor by an organization such as the Council for Accredited Certification. Finally, any contractor that provides mold remediation services may not provide mold consulting or develop the mold remediation plan and vice versa. This eliminates the classic “fox watching the hen house” situation when it comes to mold assessments and clean-up projects. We would like to thank Susan White of Sussex Environmental Health Consultants for making us aware of this new requirement.
Power(ful) Knowledge!
After the extensive power outages caused by Hurricane Sandy and the freak derecho storm in late June and with predictions of a rough winter, many people have purchased portable generators to keep the lights on and the beer cold in anticipation of the next big storm.
Although generators are a great way to provide some temporary creature comforts, they don’t come without hazards. Most people are aware exhaust fumes from gasoline-powered equipment are toxic and running a generator within or too close to your home can be lethal. Nonetheless, people continue to be hospitalized or killed by carbon monoxide poisoning due to generator misuse.
Exhaust isn’t the only danger. The method by which a generator’s power is utilized can also be deadly. Often people attempt to power the entire house by “back feeding” the generator output into an electrical outlet (such as a dryer receptacle). Not only is this illegal in most jurisdictions, it could potentially electrocute linemen working to restore electrical service.
If you feel the need to use a portable generator during the next power outage it’s best to be prepared and have the generator properly wired to a transfer switch by a qualified electrician. With a properly wired generator installed a safe distance from the house, you can relax in anticipation of the next power outage.
What Is Galvanizing?
A common way to protect steel against corrosion is to galvanize it. The term refers to the original process that entailed deposition of zinc by an electrical process, using a galvanic cell (battery). Electroplating is still used but coating raw steel with molten zinc (hot-dipping) is the more common practice. “Hot-dipped galvanized” is technically a misnomer, but a commonly accepted one. Our language is rife with them.
Not all hot-dipped treatments are equal. Sheet steel is usually coated with a thin layer, producing a uniformly smooth texture and is generally termed a G-90 coating. While certainly a “hot-dipped” process, G-90 differs substantially from what is customarily called hot-dipped, which usually refers to a G-185 coating that can be four to six times thicker than G-90. It also usually produces a rough texture that is advantageous in certain applications. For example, wood fasteners benefit from a rough texture by introducing a mechanical advantage and enhanced resistance to back-out.
G-90 can also be employed for fasteners; however, corrosion resistance is minimal and not generally recommended for exterior use. In some applications, G-90 treated fasteners should never be used. The latest generation of pressure-treated lumber utilizes preservatives rich in copper salts, presenting an environment corrosive to steel. Some dissimilar metals (like steel and copper) immersed in an electrolyte (such as various chemicals in preservatives) produce an electrochemical (galvanic) reaction.
The anode in a galvanic couple (in this case the steel fastener) dissolves over time and migrates to the cathode. The zinc on a galvanized fastener is more reactive with copper and acts as a sacrificial anode to protect the steel; however, a G-90 coating is rapidly depleted in the aggressive reaction. A G-185 coating is considered acceptable for use in treated lumber. Stainless steel is preferable, since the electrical activity between it and copper is minimal.
WIND(ows)
In the aftermath of Superstorm Sandy, a lot of people found themselves without power and with a lot of branches and leaves to collect, but how did your windows hold up? Some people out there will tell you that if your windows withstood the winds created by the Frankenstorm, then they can handle anything, but did the storm really test the integrity of your windows?
In order to answer that question, we need to understand how windows are rated. Engineers that specify windows focus on the design pressure (DP) of a window, as it represents the maximum wind load that a window can undergo without sustaining structural damage (i.e. breaking, deforming, etc.).
It is important to keep in mind that the design pressure an engineer specifies for your windows is dependent on many factors. Building type (i.e. hospital, office building, school, etc.) and geographic circumstances (coastal region vs. inland) play a major role. Additionally, engineers will require greater DP values for your windows the higher they are above the ground, as well as if they are near building corners where increased pressures from swirling winds come into play.
With that being said, many mid-rise buildings in the Baltimore-Washington area feature windows that can withstand a wind pressure of 20 psf (DP-25). Converting wind pressure into wind speed, a newer DP-25 window is rated for up to 96 mph winds, depending on the previously mentioned factors. This means these buildings are designed to handle (structurally) wind speeds expected with a Level 1 Hurricane (74-95 mph).
Another window rating system is the Performance Grade, which designates the resistance of a window to water infiltration, air infiltration, etc. The water infiltration resistance corresponds to the DP-rating of a window and is important to us because it indicates when your windows should be expected to start leaking. The average newer window in a condominium or apartment will begin leaking if you combine heavy rainfall with 40 mph winds or greater.
In the metropolitan area, the maximum recorded wind speed (gust) produced by Superstorm Sandy was approximately 60 mph. This means that the event did not produce high enough wind speeds to jeopardize the structural integrity of your windows (DP-25 or better), but the potential for leaks was expected. This really only holds true for new windows; it is not uncommon for older windows to leak at much lower wind speeds due to lower DP ratings and worn out components, such as weather stripping.
If you don’t know what the DP rating of your windows are, look for a design pressure test label such as those issued by the Window and Door Manufacturer’s Association (WDMA) or the American Architectural Manufacturer’s Association (AAMA) on the frame. Since there are many factors at play in window evaluation and selection, a design professional should be consulted to make a proper determination of your window leaks.
Thats the way, uh-huh uh-huh, I like it, uh-huh, uh-huh
The November dinner meeting of the Baltimore-Washington ICRI was eventful for ETC. Bobby Radcliffe, from our Maryland office, was elected to serve a three year term on the Board of Directors for the Chapter beginning in January 2013. Molly Carlson, daughter of Chief Structural Engineer Chris Carlson, received a scholarship from the Chapter to go toward her college education. The photo shows Molly being presented a check by the Scholarship Committee Chair, Brian McCabe of Concrete Protection and Restoration. It appears 2013 is starting off quite nicely for these two! Congratulations!
You’re Pushing It!
With winter practically here, you should have already developed your snow and ice removal plan for the year, but it’s never too late to create or amend one. Among the things to consider are areas where snow is to be pushed by plows. The lower ends of parking lots are seemingly logical places to push snow, but that’s often where storm drain inlets are located and they should never be obstructed by mounds of snow. Unless they’re mapped or marked ahead of time by your removal team or contractor, the plow operator may not know where they are and block them. It’s especially important to leave fire hydrants uncovered and accessible.
Other items that should be marked are speed bumps and any utility covers that extend even slightly above the pavement surface. Snow plows can gouge integrated asphalt speed bumps and dislodge or break prefabricated devices.
Snow removal on exposed parking garage decks present another set of problems. If the deck is surfaced with a waterproofing or protective coating, conventional steel-bladed snow plows can damage the material. There can be expansion joints, lighting bollards, stand pipes and other items that should be marked and avoided. A blocked/buried fire standpipe could have catastrophic consequences.
Your crew or contractor should also practice judicious use of deicing agents (salt, calcium-chloride, etc.). Improper use will damage concrete and new concrete (less than a year old) is particularly susceptible. If you’ve had sidewalks, stair assemblies, or curb and gutter assemblies replaced in the past year or so, they should be mapped and treated with extra care with respect to ice control. Consider using sand instead of deicers in those areas.
Problems Caused By Sandy
Hurricane Sandy certainly caused a lot of problems relative to water intrusion issues that occurred in places where they had not been previously seen. Site drainage around buildings is very important and numerous problems were reported due to clogged gutters, downspouts and other water drainage components that need to be carefully checked and maintained on a regular basis.
We have also seen several concerns related to problems with storm sewer systems and underground lines that service basements or low lying drains. If these important drainage features become clogged, a large storm like Sandy can cause extreme water back-up that can readily penetrate into buildings. In order to check storm sewer lines and underground drain lines, consider retaining a qualified plumber to run a camera through these lines to check for obstructions and/or breaks in the pipe walls or joints. Keeping these lines clear can greatly help prevent unwanted problems.
Covering Your Tracks
Field work or not, Sandy does not allow us to come back and track dirt into the office. Those that do…pay the price! Luke, our newest engineer, had to learn the hard way. A quick trip to the cleaning closet and he was back in Sandy’s good graces. It’s nice to know this guy can not only operate a Delmhorst, Psychrometer and thermal camera….but also a good ol’ fashion HOOVER.
Just for your information, I wouldn’t ask him to do windows!
Balcony Insulation and Condensation
Cantilever balconies are commonly seen protruding from the façade of condominiums and apartments. However, this arrangement can lead to problems arising from heat transfer and condensation, resulting in mold growth.
Typically, steel framed cantilever balconies have beams that extend into the building and connect to the structure. Concrete balconies are usually cast integrally with the rest of the floor. During winter months, the exposed balcony structure becomes cold and when it meets the warm building interior, typically near a sliding glass door, thermal transfer increases, as does the possibility for condensation and mold growth. Building owners should be aware of this possibility and watch for condensation forming in the area under the carpet or wood flooring, near the balcony.
Fortunately, for new buildings with cantilever balconies, products are now being produced to prevent condensation and mold by inserting a thermal break (insulation) between the exterior and interior portions of these structures. These new balcony structural inserts can carry significant weight, while preventing interior heat transfer. The most common materials used for these products are stainless steel and fiberglass reinforced laminate composites. Although these are new products, they appear promising.