Blog
View All Blog Postings
Types of Wood Members
As construction techniques continue to grow and evolve, choosing the right material for your job may seem a little overwhelming. This especially rings true with timber construction. Gone are the days when you just needed to specify the size and tree species. Here’s a guide to help you choose the timber that is best suited for your job.
Sawn Wood‐ Traditional sawn wood is still the commonly used type of lumber. Almost all structural sawn wood beams originate from softwood tree species, such as Pine or Douglas Fir. Structural sawn lumber is further classified through stress‐gradings, which establish standard working values for properties that can be used to determine the load‐bearing capacity of these members. Typical lumber grades can be seen on the adjacent table. Traditional sawn lumber can be used for almost all structural member, such as joists, beams, posts, etc.
Laminated Veneer Lumber (LVL)‐ Laminated veneer lumber belongs to a family of engineered wood products called structural composite lumber (SCL). Structural composite lumber members are comprised of blocks of lumber materials know as “billets”, which are veneers, strands or flakes of dried and graded woods adhered together. For LVL beams, thin wood veneers are bonded together into a billet, with the grain of all veneers running parallel to the length of the beam. Called “parallel lamination”, this orientation allows LVL beams to exceed the load‐bearing bearing capacity of similarly sized sawn lumber and be used for long‐spanning load‐bearing members, such as beams or rafters.
Parallel Strand Lumber (PSL)‐ Parallel strand lumber, another type of structural composite lumber, is manufactured using long, thin strands of wood (typically the waste material from plywood manufacturing), which are laid parallel and bonded together to form a billet. Similar to LVL members, PSL members can be used for long‐spanning beams where greater load‐bearing capacity is required. Additionally, PSL members are also frequently used as columns.
Laminated Strand Lumber (LSL)‐ Similar to PSL, laminated strand lumber is comprised of long, flaked wood strands of hardwoods not normally used for structural applications (e.g. maple). The wood strands used for LSL are typically shorter and thicker then those used in PSL, leading to lower load‐bearing capacity. Typically, LSL members are used for wall framing, such as studs and headers. LSL members can also be used for intermediate spanning beams and rim boards, where the higher strength LVL or PSL members are unnecessary.
Oriented Strand Lumber (OSL)‐ Oriented strand lumber is comprised of flaked wood strands strands very similar to those used in LSL member, but the length of the strand has been reduced and the thickness increased. As such, OSL members can typically be used in similar situations where LSL members are utilized
What to Look for When Concrete Deteriorates
As with all building components, concrete slabs, beams, and columns will inevitably deteriorate and need repair throughout the lifetime of a building. Most concrete deterioration is linked to the corrosion of embedded metal elements, such as steel reinforcement bars. As the steel elements rust, it expands and occupies more space than the original steel, slowly building up pressure on the concrete until the concrete separates from the steel reinforcement. In the most extreme cases, the concrete will separate from both the steel and surrounding concrete, resulting in a condition known as “spalling.” Spalled concrete can be easily identified by visual inspection; it would be hard to miss a chunk of concrete missing in a wall or beam!
However, deteriorated concrete that separates from the steel rebar, but not the surrounding concrete, can be trickier to find. This deterioration is known as “delamination.” Identifying delaminated concrete requires non-destructive testing, such as sounding of the concrete elements, which tends to be the most common cost-effective option. Areas of delaminated concrete can be found by listening for hollow areas, which make a low, drum-like noise, while sounding the concrete with a hammer or by chain dragging. The hollow sound is caused by the air gap between the separated concrete and rusted steel. If you’ve noticed some suspicious-looking concrete in your building, reach out to ETC to help evaluate your building today.
Benefits and Short-Comings of Glue-laminated Timber (Glulam)
Glue-laminated lumber (also known as Glulam) is a versatile and innovative material widely used in the construction industry and has become increasingly more popular in recent years for its many benefits. Glulam is composed of wood laminations that are bonded together with high-strength adhesives to form a strong member.
Benefits
Glulam members are customizable to be formed to specific lengths and curvature to fit the needs of most residential and commercial wood-framed properties. Most notably, in 2019, the construction of an 18-story building in Norway was formed from solely glulam and laminated timber beams. Glulam beams also have a much better environmental impact compared to steel or concrete beams for their carbon storage capacity. Furthermore, glulam beams have good fire resistance and can outlast steel beams due to a charred carbon layer that is formed on the surface of the beams which insulates against heat. In our industry, they are typically utilized to span large openings that regular timber beams cannot, like balcony door and breezeway openings.
Shortcomings
While the benefits for glulam beams look to be impressive, the necessity of glulam beams over other engineered lumber beams may not be the most cost-effective solution, as the cost for glulam beams are higher than they are for many other engineered lumber. Deterioration of glulam beams is common due to high humidity areas and water intrusion through improper or unsealed flashings. While glulam beams are often marketed for their ability to be exposed to the natural environment, they are often very susceptible to deterioration due to construction methodologies. Glulam beams are prefabricated to an exact size; therefore, if the beams need to be cut to fit new dimensions, the entire beam can become susceptible to deterioration if the cut portions are not properly protected with a sealer material on-site.
Planning a Wheelchair Ramp
We are excited to share our recently completed wheelchair ramp for a historic building in Washington DC. The building residents wanted a ramp that provides handicap accessibility for their residents. We designed the new ramp at the exterior of the building that slopes from the grade level to the basement level with interior elevators. The residents with a wheelchair now have handicap accessibility to all the levels of the building.
The process and construction required preparation of drawings and approvals from the Historic Preservation Office, Building Department and careful planning with Owners, Contractors and Manufacturers.
If you are planning to build a wheelchair ramp, also known as handicap accessible ramp (in a historic or non-historic building), it would be best to have a check list of design considerations before starting your project.
- Familiarize yourself with the International Building Code (IBC), American Disability Act (ADA) and American National Standards Institute (ANSI) A117.1 that determines rules and regulations for wheelchair ramps.
- Most of the states and local jurisdictions have adopted IBC governed by International Code Council. Always make sure to check with your local permit office for building code and permit requirements.
- Handicap ramp requirement is eight (8) percent slope, that means your ramp should not be steeper than one-unit vertical in twelve-units horizontal. For example, if you are planning a ramp for a height difference of twenty-four inches (2 feet vertical), it will require two-hundred and eighty-eight inches (24 feet horizontal) of floor space. Maximum vertical height allowed in any ramp is thirty (30) inches.
- Minimum ramp clear width is thirty-six (36”) inches, minimum headroom height is eighty (80”) and minimum landing width is sixty (60”) inches.
- The height of railings is between thirty-four (34”) and thirty-eight (38”) inches above walking surface. Handrail material can be wood or metal. We recommend finished wood handrail for interior ramps and corrosion-resistant metal handrail for exterior ramps.
- If the ramp is located at the exterior, plan for storm water drainage and connection to site drainage system.
- Safety comes first, consider slip-resistant finish material for the walking surfaces.
Cooling Season – Things To Consider
With the winter season and cold weather at a close, we turn our attention to the warmer spring months and the cooling of our buildings. This change of seasons can bring about new challenges for a building and owners may be concerned if their Heating, Ventilation, and Air Conditioning (HVAC) system is providing a safe environment and staying cost-effective. Although these are concerns throughout the year, you may be wondering how the warmer weather will impact your building and if it is time to evaluate your current HVAC system. There are many “Things to Consider” when it comes to warmer weather and once you understand what is affecting your building, you can approach solutions to make them better. Read on to learn about some strategies you can invest in to make your building healthier and more cost-effective during the spring.
At this time of year, plants begin to bloom and there tends to be large quantities of pollen in the air, which can reduce the overall outside air quality. This air can make its way to your mechanical equipment, and eventually to the inside of your building, which may adversely affect occupants. To combat this issue, it is highly recommended to change air handling unit filters more frequently and possibly consider filters with a higher Minimum Efficiency Reporting Value (MERV) rating. This rating specifies the ability of a filter to capture air contaminants/particles (including pollen) and a higher rating will help capture more. However, the air filters should be checked more frequently and replaced if needed due to the pollen accumulation.
Beyond the health implications, spring also gives way to changes in the energy demands of a building. Like the fall, the spring months have milder outside temperatures and humidity, lowering the energy demand required to maintain comfortable spaces. Rather than working against extreme heat losses (or gains) caused by the winter (or summer), your HVAC system may deal only with the heat gains caused by sources from the sun’s radiant heat, lights, and people. These heat gains still require cooling, but many times during the spring, the outside air conditions are cooler than the supply air from the HVAC system. Therefore, instead of wasting energy to mechanically cool air, an economizer can be used to condition your space. An economizer will allow your system to supply outside air directly to your building, thereby reducing or eliminating the need to use energy to cool your supply air. This is typically referred to as “free cooling” and can greatly reduce your energy consumption and costs.
In addition to being more cost-effective, economizers are inherently meant to bring in more outside air to your building and will help increase the indoor air quality – just remember those air filters! Although this equipment can provide significant cost savings after it is installed, it can be more complicated to integrate into an existing building design. Using the economizer strategy must be carefully thought out and designed to make sure that the system is running properly and efficiently.
You may not know where to start with improving indoor air quality or decreasing the energy consumption of your commercial space. Many factors and variables can affect the health of your occupants or the number on your bill — with an untrained eye, you might be unaware of your building’s limitations and energy saving potentials. In that case, it is a good idea to schedule a building energy audit and systems assessment with a professional mechanical engineering firm.
Experts will help you determine where your energy is wasted and how to decrease the waste. A professional understanding of your energy expenses and mechanical design will help you invest in the right solutions, protecting your occupants and saving you money in the long run.
Why Use A Certified Welding Inspector?
Having a Certified Welding Inspector (CWI) on your project will help increase the overall quality, consistency and repeatability of welds and welding processes. A CWI is trained and certified to perform inspection/observation in four major areas of welding: 1) Materials and Design, 2) Qualification of Welders and Welding Processes, 3) Fabrication, and 4) Inspection.
- Materials and design: The CWI will review design documents (i.e. drawings and specifications) to confirm that the designed welds and welding materials conform to applicable welding codes, such as American Welding Society.
- Qualification: The CWI will review Welding Procedure Specification(s), as well as all welder qualification records, to confirm that all welding personnel and processes to be used on the project are certified/qualified as required by applicable codes.
- Fabrication: Prior to the start of welding, the CWI will review the welding equipment and materials on site, as well as condition and surface preparation of base metals, to confirm compliance with the design documents and all applicable welding codes.
- Inspection: The CWI will visually (nondestructively) inspect welds during and after installation to confirm compliance with the design documents and all applicable welding codes. Where other nondestructive testing (NDT) is required, the CWI will observe the testing procedures and will review test results.
Please contact Savannah Penn, CWI at: spenn@etc-web.com
New Requirements For DC Buildings
Washington D.C. has established the 2021 Building Energy Performance Standards (BEPS) which became effective January 1, 2021 for existing and new buildings. The new standards set requirements for a building’s Energy Start score or equivalent Source Energy Use Intensity (Source EUI) based on the property type classification. These standards are part of a three-stage plan to meet the new energy performance standards in existing buildings and achieve energy and climate goals stated in the Sustainable DC plan, which aims to reduce the greenhouse gas emissions and energy consumption by 50% by Year 2032.
This first compliance period, which start this year and ends in 2026, affects private buildings with a footprint greater than 50,000 square ft and D.C.-owned buildings greater than 10,000 square ft. Phase Two, starting in 2027, will require building greater than 25,000 square feet to comply, and the final phase, starting in 2033, will include all building greater than 10,000 square feet. Buildings that do not meet the BPS will be placed into a compliance cycle and will have the end of the performance period to comply to the standards or be subject to fines.
A guide to the 2021 BEPS can be found at https://doee.dc.gov/publication/guide-2021-building-energy-performance-standards.
Should You Paint Exterior Brick? Probably Not.
Stroll down any street in Baltimore or Washington, D.C. and you are bound to find numerous brick buildings sporting a fresh coat of paint. The trend of painting brick facades has become popular over the last several years and while painting brick can provide an updated appearance, it may not be the best idea.
Brick masonry is naturally porous, meaning it contains small holes which allow liquid and air to pass through. Two common types of masonry wall assemblies we see locally are drainage wall systems and mass wall systems, both of which manage the water that inevitably enters through the porous masonry. Drainage walls contain an air cavity between the brick veneer and the back-up structure, allowing water to travel within this cavity and exit through flashings and weep holes. In comparison, mass walls contain multiple layers of brick masonry which rely on the wall thickness and bond between the bricks to resist water penetration into interior spaces. The majority of older and historic masonry buildings consist of a mass wall system.
Most paints readily available are not vapor permeable, more commonly known as breathable. Therefore, when paint is applied to bricks, they lose their porous nature which is critical for allowing evaporation in mass wall systems. The loss of porosity can cause any moisture that enters the wall system (through small cracks or other defects) or was present prior to paint application, to become trapped. This can cause bricks to deteriorate faster and can potentially trap moisture against interior framing elements, resulting in structural damage. Trapped moisture can also cause the paint to blister and flake, creating an unappealing appearance.
Additionally, masonry requires periodic maintenance. Painting brick can make it difficult to identify defects, such as cracked bricks and mortar, that should be repaired. Paint is also relatively permanent. Once brick is painted, removal can be very challenging and could result in significant damage to the brick walls.
However, there are options for updating the appearance of a brick façade, including brick stains and some breathable coatings. If you are interested in modifying the appearance of a brick structure and are looking for professional help, ETC can provide a solution.
How To Save On Energy Bills In Winter
If you cringe at the sight of your commercial space’s winter energy bills, it may be time to invest in energy-saving strategies. Once you understand why your bills are so high, you can approach solutions for decreasing your energy consumption. Several factors contribute to high energy usage in larger buildings, some specific to cold weather. Learn how you can save money on your energy bills in winter.
Factors That Influence Your Energy Bills
Electricity is a modern necessity, powering everything from lighting to temperature control to large appliances and equipment. Providing the energy required to power an entire building can be expensive. The good news is that you can take steps to lower your energy costs. Learn why your energy bill might be higher than it needs to be — and what steps to take to save on winter energy bills. Here are a few factors that influence energy efficiency.
Using Older Appliances or Equipment
Technology has improved over the years. Appliances, equipment, and tools have become more efficient, eating up less electricity to operate. If you’re using older devices or equipment, you may be sinking more funds than necessary into your energy bills. Upgrade your building’s equipment to lower your power consumption. It’s best to pay attention to Energy Star labels when available — Energy Star started rating products’ efficiency in 1992. If your appliances are older than that, it’s time to think about an upgrade.
Using Appliances or Equipment More Than Needed
It’s no surprise that using equipment and devices more than necessary raises energy consumption. Turn off lights, fans, and equipment when not in use. Install motion sensor lights in case someone forgets to flip the switch on their way out of the building.
Additionally, only use power tools and equipment at the lowest setting necessary. Using tools at the maximum power regardless of purpose will require more energy than needed. Make sure everyone is on the same page about using pneumatic tools or other equipment at the lowest necessary setting.
Lacking Heating, Ventilation, and Cooling (HVAC) Maintenance
Optimized HVAC efficiency is necessary for any commercial space. Accumulated dirt and debris affect efficiency by clogging filters and ducts. If you’ve neglected regular HVAC maintenance, this could contribute to higher energy bills. You can reduce your energy expenses by scheduling regular preventive maintenance. This setup will keep your system running as it should. It’ll also reduce the likelihood of major and expensive HVAC issues and extend the system’s life span.
Why Are Energy Bills for Commercial Spaces Higher in Winter?
Some energy efficiency factors are specific to winter. If your commercial space incurs high electric bills during the winter months, think about these contributing circumstances.
Buildings Are Occupied More Often
When outdoor temperatures turn frigid, people tend to occupy indoor spaces more than ever. The more time people spend inside your building, the more electricity they’re bound to use by turning on lights and operating equipment or electronic devices. Occupants expect spaces to be at a comfortable temperature, which means heating costs can accumulate.
Heat Leaks Through Cracks and Openings
Comfortable temperatures are necessary for both effective employees and satisfied patrons. As people occupy indoor spaces on a near-constant basis, they expect a sufficient level of warmth. Heating large buildings in the winter can cost a great deal of energy — if any of that heat is lost, your energy bill will represent wasted dollars. Heat escaping is one of the main culprits of high winter energy bills.
Top 5 Tips to Save Money on Winter Energy Bills for Commercial Spaces
You can take several steps to decrease your energy consumption and pay less this winter. If you’re wondering how to lower commercial energy bills during winter, follow these five simple tips:
1. Equip Your Building With Automatic Controls
Automatic controls ensure efficient energy use, leaving less room for human error. They may also provide you with helpful data regarding your energy usage. Equip your building with programmable thermostats and be mindful when adjusting the settings. Using this technology, you can conserve heat in your commercial space without lifting a finger. Set your thermostats to decrease the temperature when areas are not occupied. Be sure to keep the temperature high enough to avoid frozen pipes.
If you have a traditional thermostat, consider replacing it with a programmable one. If you’re paying to heat large spaces, this is a necessity for easy and convenient climate control. Doing so will help you gain more control of your building’s temperature and ensure employees and patrons are comfortable. It’s also a good idea to invest in automatic timers and movement sensors for your lights. That way, you’ll only pay to light up occupied spaces instead of constantly keeping the lights on throughout your facility.
2. Find and Address Leaks
As mentioned above, cracks and openings allow heat to go to waste. If your building has temperature leaks, your heating system will struggle to match the thermostat’s temperature and work much harder to heat spaces. To prevent this from happening, have a professional evaluate your building for any potential heat leaks. They’ll fill leaks with caulk or insulation, and they may also weatherstrip windows and doors to stop air infiltration.
Keeping the building’s heat sealed in will ensure a lower winter energy bill and give you peace of mind — you will no longer lose heat to the outdoors.
3. Insulate Water Heater and Pipes
Your building’s water heater and pipes can be sources of lost energy. If your water heater is warm to the touch, it might need better insulation. Contact a professional service to improve water heater insulation. You’ll need to do the same for your hot water pipes. Proper pipe insulation prevents heat loss as hot water travels from the water heater to a faucet, conserving energy. If not well-insulated, pipes may cause significant issues by freezing.
Frozen pipes can result in pressure buildups and bursts, causing flooding and subsequent damages. Such flooding can destroy equipment, furniture, or flooring and induce extensive repair costs. It can also present a safety hazard if it reaches electrical equipment or stands for any length of time, harboring bacteria or mold. Insulating your pipes will help you avoid pipe bursts and improve efficiency at the same time.
4. Use Efficient Lighting
If your building is fitted with traditional incandescent light bulbs, you’ll want to replace them with energy-efficient versions. Light-emitting diodes (LEDs), as well as halogen and fluorescent lights, use between 25% to 80% less energy than traditional incandescent bulbs and have a much longer life span. Energy-efficient bulbs also come in various colors and dimming capabilities, which can help them fit in with your business’s needs.
Once you’ve installed energy-efficient lighting, take advantage of automatic controls for further savings. Whenever possible, utilize natural light to save on energy costs. You might consider installing more windows if needed. Natural light has many health benefits, so your employees, patrons, or other occupants will be grateful.
5. Schedule an Energy Audit and a Utility Usage Assessment
You may not know where to start with decreasing your commercial space’s winter energy bills. Many factors and variables can affect the number on your bill — with an untrained eye, you might be unaware of your energy efficiency losses. In that case, it’s a good idea to schedule a building energy audit and utility usage assessment with a professional mechanical engineering firm.
Experts will help you determine where your energy costs lie and how to decrease them. A professional understanding of your energy expenses will help you invest in the right solutions, saving you money in the long run and giving you fitting answers for your energy usage issues.
Contact Engineering and Technical Consultants, Inc. to Get Started
If you’re ready to take proactive steps to decrease your energy bills this winter, start by bringing in the experts. With the help of Engineering and Technical Consultants, Inc. (ETC), you can invest in wise solutions to conserve energy. Request a building energy audit and utility usage assessment to learn about your energy consumption so you can make informed decisions. To decrease your winter energy bills, contact ETC today.
Understanding Your Building Components
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.
Shortcoming of Corrugated Plastic Pipes
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:
Welcoming Rob Broczkowski To Our Team
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.
