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One of the most pressing questions when designing repairs for concrete slabs is whether or not the slab is post-tensioned, and if so, the locations of the stressed tendons. Accidentally cutting through a stressed tendon will decrease the slab’s load carry capacity, could possibly endanger the structural stability of the entire slab, and may result in injury to those in the building.
If present, the tendons and other imbedded items can usually be located through the use of ground penetrating radar equipment, but locating the tendons would be more accurate if the original building plans and shop drawings were available for review. It is imperative that property owners keep a copy of original building plans and documents and a comprehensive running log of all building studies, repairs, etc. in order to provide engineers and repair contractors with the most complete picture of their building’s history; these documents can be incredibly helpful when trying to understand your building and should be preserved. Providing ETC with as much information as possible will help us provide you with a comprehensive repair plan and avoid hidden headaches during construction.
Sometimes, differences in construction materials that might seem insignificant to the untrained eye can have long lasting implications and cause headaches down the road. ETC has seen this situation arise plenty of times when evaluating new below-grade drainage systems, specifically regarding the type of piping to be used: corrugated plastic pipes or rigid PVC pipes. Corrugated plastic pipes are thin walled pipes, typically .02” thick, with a series of grooves running parallel to each other along the length of the pipe, while rigid polyvinyl chloride (PVC) pipes are thicker, ranging from .1” to .5” depending on the diameter and schedule of the pipe, and have smooth inner and outer walls. Corrugated pipes are typically cheaper than PVC pipes and are easier to install and connect, making them a favorite of DIY-ers. However, in our experience, the increased flexibility and installation ease comes at a great sacrifice to the durability and effectiveness of the drainage system.
Corrugated pipes tend to clog more frequently then solid-walled pipes due to their ribbed profile and
are more difficult to clean as well, as an auger or plumbing snake could easily tear through the pipe’s
thin plastic walls. The thin plastic pipe walls are easily crushed as well, especially when backfilling with
compacted soils or stone. We have observed drainage systems where newly installed corrugated pipes
were crushed during construction, rendering a sizable portion of the drainage system useless from the
start. ETC always recommends rigid PVC pipes over corrugated pipes for below-grade drainage
applications in order to provide clients with an effective and durable drainage system. If you’re having
drainage issues and looking for professional help, ETC can provide a long-last solution to address your
needs. Contact us for a free proposal:
We are pleased to introduce our new Mechanical Engineer, Mr. Robert Broczkowski, PE. Rob is a graduate of University of Maryland and has over 10 years experience in the mechanical engineering field. His background includes building energy and cost analysis, HVAC design, and construction administration. Rob has worked on many projects in the Mid-Atlantic region, applying key skills in system evaluation and design, equipment selection, and other critical HVAC principles. He is also an active member in the engineering community holding a chapter position in his local professional society for over 5 years. Rob looks forward to working with you on upcoming mechanical projects. Please feel free to contact him for a free proposal.
When most property owners think about ventilation upgrades, they often consider installing new windows and doors or replacing the existing HVAC equipment. However, they often forget to consider one of the most important locations within their building: the crawlspace. Improper ventilation can allow for humid air to become stagnant within the crawlspace, spurring microbial growth and accelerating the deterioration of both wood and concrete structural elements. Given the difficulty accessing the crawlspace, as well as the typical space restrictions, crawlspace structural repairs can be quite costly and lengthy, but proper ventilation upgrades can help curtail these repairs.
Allowing for adequate airflow is crucial for ensuring the longevity of the crawlspace structural elements. The International Building Code (IBC) imposes certain ventilation requirements given the size of the crawlspace area and other circumstances, such as climate conditions and crawlspace construction. In our experience, it’s not uncommon to find crawlspaces with either undersized vent openings or simply too few openings at all. Additionally, we typically find vents that have been covered with mulch or other landscaping, rendering the vent useless. The number of required vents can be reduced through the installation of fans within the foundation walls or the installation of a vapor barrier over the exposed crawlspace soils, given that the vapor barrier made of qualifying materials, properly installed, and in good condition. If you’re overdue for a crawlspace inspection, reach out to ETC to help evaluate your crawlspace today.
A heating, ventilation, and air conditioning (HVAC) system is a major contributor to the indoor air quality of any building. If your HVAC system is appropriately designed and maintained, it can help improve the quality of the air. But a poorly designed or maintained HVAC system can make the air quality worse, which can lead to health problems among building occupants.
At ETC, we provide expert HVAC and mechanical engineering services to improve your HVAC system and help to prevent the spread of germs throughout your building.
How Indoor Air Quality Affects Your Health
According to the EPA, the concentration of certain indoor air pollutants is two to five times greater than the average concentrations found in outdoor air. People exposed to poor indoor air quality may experience health issues such as headaches, fatigue, sneezing, coughing, nausea, and other symptoms.
Your HVAC system has a significant impact on indoor air quality. Issues like excessive humidity, extreme temperature variations, and unpleasant odors coming from the air ducts all indicate that your HVAC system could be harming the air quality. If these HVAC issues are left untreated, they can eventually cause short-term and long-term health complications.
During cold and flu season, viruses spread quickly if the air in your building is stagnant and unpurified. An HVAC system is responsible for air movement within your building, which means it can prevent the spread of germs if there is proper circulation. If not, the system may contribute to disbursing the contaminants that result in illness.
Recently, the relationship between the coronavirus and HVAC systems has become a major concern. While there is currently no documented evidence that the coronavirus can be spread through HVAC systems, building owners can minimize the risk by maintaining a clean and updated HVAC system that promotes healthy indoor air quality.
How ETC Can Improve Your HVAC Systems
With the right features and maintenance regimen, your HVAC system can help keep everyone in your building safe and healthy. At ETC, we know precisely how to optimize your HVAC system for better air quality. We may suggest solutions like installing UV lights and media air filters, which neutralize or trap contaminants so they will not be recirculated into your building. Our recommendations are based on a thorough assessment of your current system and our expert knowledge of HVAC systems.
We use all the latest computer modeling software to plan your system upgrade, and we consult on everything from design to construction. We pride ourselves on being the best, so you can trust that when you work with us, you will receive the attentive and high-quality service your project deserves.
Contact ETC for HVAC and Mechanical Engineering Services
We work with clients across different building segments, including commercial, retail, recreational, residential, governmental, institutional, and historical, and we tackle even the most challenging projects with precision. Contact us today to learn more about our services.
Wood-framed balconies can look sharp on a building, not to mention the comfortable outdoor spaces they can provide. One of the most important ways to protect your wood balconies and decks is to prevent water from deteriorating the framing. Deterioration typically occurs when water cannot properly drain and becomes trapped against wood surfaces. Consequently, this type of deterioration oftentimes occurs where we cannot see it!
A common location for deterioration on wood balconies is along framing members that connect to the
building (i.e. ledger boards, joists, etc.). Water often migrates behind these framing members and does
not have a way out. Additionally, frequent moisture in this location can deteriorate interior building
framing elements, such as wall studs or floor joists. This photo shows a building exterior following
demolition of wood-framed balconies. The deteriorated exposed framing on the left-hand side shows
why it is so important to protect wood framing from trapped water. What is the important difference
between the left and right sides?
A metal flashing was installed along the original balcony framing on the righthand side, but not the left. Flashing is an impervious material, such as metal or plastic, that prevents water from intruding to an interior space by providing an alternate drainage path (see the sketch below from FEMA Home Builder’s Guide to Coastal Construction Technical Fact Sheet No. 24 for a typical ledger flashing detail). After more than 30 years of exposure to the elements, we can see how flashing played an important role in protecting the wood framing of the building shown.
Does your building have lightning rods? The summer of 2020 brought with it some incredible lightning storms. Without a lightning protection system, buildings may be at risk of lightning-related damage, including electrical fires and physical damage to the structure. For example, take a look at the lightning damage to these rooftop parapet walls on a local high-rise building. Bits of concrete tumbled down to ground level, and the embedded steel even featured black char marks. Fortunately, the damage was minimal, quickly repaired, and nobody was hurt during the storm!
Although the cost for installing lightning rods is known to be high, protection against lightning-related damage can save buildings and save lives. Check out this Lightning Protection Institute website for an overview of lightning protection standards, technology, and design: https://lightning.org/lightning-protection-overview/
When a pandemic hits, it’s no surprise that people’s way of life changes with it. You try to say farther away from other people, wear your mask out in public, and scrub your hands with hand sanitizer much more often. What might surprise many, however, is that a pandemic can impact the way buildings are designed. In the early 20th century, for example, tuberculosis inspired architects to design buildings with elements that could help people recover from it.
The new designs they incorporated, such as light-colored rooms and expansive windows across long walls, ended up becoming mainstays in architectural design as a whole, making up much of what we now recognize as modernist architecture. In the same way that tuberculosis inspired new architectural styles, COVID-19 will likely lead architects to develop new designs that could lead to major changes in the field.
As the hurricane season is fast approaching, it makes sense to have an architect and engineer look at possible areas of damage/water intrusion in your building. This is the perfect time to address these issues before any damage is caused to your building due to heavy rains and/or high winds.
Here is a list of areas to inspect before the next rainstorm.
- Site Grading; Making sure that the soil is sloping away from the building;
- Building and Site Drains; Ensure that the drainage provisions (such as roof gutters, downspout, landscape drains) are clear of debris and are operational. If the gutter terminates at the building foundation, consider extending it away from the building.
- Exterior Cladding; Ensure that the building facade components are adequately secured to the building, such as gutters, downspouts, metal coping, canopy, cornices and are not loose or partially detached.
- Sealants; Ensure that an excessive opening in the sealant joint is visually inspected and repaired.
- Roofing; Inspect roofing membrane and associated components (joints, penetrations, parapet wall caps, chimneys, etc.) to help assure that these components are intact and watertight.
The wind driven rains can be very unpredictable and can cause damage. However, larger damage to the building can be avoided/minimized, if the above mentioned areas of concern are addressed before a major rainstorm.
It looks good and it feels nice underfoot, but carpeting is one of the worst things you can do to a balcony. Carpet, artificial turf and similar floor coverings tend to hold water, impair drainage and retard evaporation. The longer water remains in contact with concrete, the more opportunity it has to exploit small cracks and the natural porosity of concrete in pursuit of a favorite target… steel (in this case the embedded reinforcement). When water contacts steel, it usually results in corrosion (rust). Rust occupies more space than the parent metal and the force that accompanies its formation is more than enough to shatter (spall) concrete that confines it.
If you simply cannot live without carpet on your balcony, at least coat the concrete with a protective surfacing; but beware, appropriate coatings are not cheap (and mere paint will not suffice). It should also be noted that carpeting will reduce the serviceable lives of coatings and fairly frequent re-application may be necessary.
It’s equally ill-advised to carpet wood balconies. Prolonged exposure to water contributes to decay (rot) and distortion (warping/cupping) of the wood, as well as corrosion of steel components.
Retaining walls offer a mix of form and function. A retaining wall can hold back the soil behind it, playing an important role in preventing erosion, particularly on hills or in areas where plants can’t grow. Retaining walls are also used to create flat, usable ground on hilly terrain for things such as parking lots and sports fields. A retaining wall can also enhance landscape designs. For example, a landscape architect or designer might build retaining walls to create different levels of terrain or different elevations in a garden.
Retaining walls differ from the walls that hold up a building or another structure. While the walls of a home or apartment building are designed to support vertical loads such as ceilings and roofs, retaining walls are meant to support horizontal loads. For that reason, the design and engineering of a retaining wall differ from the design and engineering of the wall of a building.
While there are similarities in the types of materials used for building retaining walls and other types of walls, some materials are better suited for use with retaining walls. In this guide, we’ll take a look at some of the most commonly used materials for retaining walls.
Among growing concerns for the Owners of existing buildings are the utility bills and the energy efficiency of the building’s equipment. A big question that is often asked is, “Am I living in a healthy indoor environment”? It is also very interesting to note that the wealth and health of an individual has a direct relationship to the overall energy efficiency of the building.
One such standard for improving a building’s overall energy efficiency is Leadership in Energy and Environment Design, LEED Certification. Developed by the US Green Building Council, USGBC in 1994, LEED is a green building rating system that provides a framework for creating highly efficient green buildings and providing ways for cost-savings in new and existing buildings.
Among many of the benefits of having a LEED certified building are cost savings over the life of the building related to lower energy and operating costs. Additional benefits include increased building value, higher rents, improved air and water quality, and a healthier work and living environment.
LEED certification is viewed from a perspective of a life cycle of the building. Therefore, project delivery is not only design and construction of the building. LEED certification dives deep into the efficiency and optimization of building performance during occupancy, as well as the end of the life span during demolition and recycling of building materials. Thus, from the beginning of the project, LEED requires a vision that identifies green building goals, budget, timeline, return on investment and standards. This is an integrative process, that requires input from all stakeholders during the early pre-design phase of the project. The project team includes Owners, Occupants Facility Managers, Janitorial Staff, Architect, Engineers, Interior Designers, Landscape Architect, Energy Consultants, and the General Contractor. LEED certification process ensures design, construction and building commissioning meets the agreed upon green building goals.
The LEED rating system is tailored to various buildings types, depending on the use and size of the building, as well as whether it is a new or existing facility. The most common rating is LEED BD+C, which stands for LEED Building Design and Construction, which applies to new construction or major renovations. A LEED ID+C (interior design and construction) rating applies to the interior fit-out, LEED O+M (operation and maintenance) applies to existing building improvements, and LEED ND (neighborhood development) applies to new land development projects.
LEED has a major areas of performance criteria that can be measured through a point system. Major areas of performance criteria are Location and Transportation, Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, Innovation and Regional Priority. There are prerequisite points that a project must earn, and each category has point credit system that defines a green sustainable goal. Project certification is based on 100-point scale system, which adds up to four certification levels: Certified (40-49 points), Silver (50-59 points), Gold (60-79 points), and Platinum (80+ points).
Currently, LEED certification for existing buildings is a growing trend and the most important reason for this trend is a healthier indoor environment and an energy efficient building.