Researchers at the University of Maryland have found a way to make wood transparent, which could change the way that we utilize this building material.
- Most importantly is your safety. Be sure to wear appropriate protection such as a hard hat, construction boots, yellow safety vest and safety glasses.
- Make an appointment with the contractor/management and be familiar with the overall layout, prior to your visit. Upon arrival check in with the construction site supervisor.
- Take photographs of the construction site and make field notes of your observations. Don’t forget to document date, time, project name and whom you met.
- Take along a 25-foot tape measure for field dimensions and a flash light for enclosed rooms that may not have electricity.
- The general contractor has authority and responsibility for the job site, therefore don’t direct workers, get in a debate or offer advice. It is best to state the purpose of your visit, make observations and be courteous
We recently ran into an unusual item at a property – two hour, fire rated windows. The assemblies looked like “regular” windows but after some digging through the building drawings, it was determined that the windows were fire rated. The building code requires that exterior building walls within ten feet of a property line must be constructed using recognized fire rated assemblies. This includes the glazing.
Fire rated windows have special steel frames (fiberglass, vinyl and aluminum cannot stand up to the heat) and multiple layers of glass (up to about 1-1/4” thick) that allows them to provide protection against radiant heat, smoke, and fire. They have been tested to confirm their ability to resist fire and even the force of a fire hose stream in accordance with ASTM and NFPA standards.
Fire rated windows may look like a normal window, but these windows with super powers cost significantly (about 15 to 20 times) more than a standard window
Advances in imagining and sonic technology have long been embraced by engineers and are being used every day to help evaluate buildings and building systems. These gadgets can allow for an in-depth, minimally invasive, and cost-effective inspection with rapid results. Plus, it is fun to pull out a toy that you might see in an action movie to help figure out a problem. The following are found in most local consultant’s arsenals.
- Thermal Camera – Police, military, and ghost hunters use them and so do engineers. Infrared thermography allows us to “see” hot and cold areas and can allow for a rapid scan of a room, roof, electrical panel, radiator, or a building façade for thermal anomalies. These normally are found to be air and water leaks and help pinpoint locations that should be inspected more thoroughly. Blue areas are cold and red are hot.
- Drones – Unmanned flying aircraft now are easier to maneuver and can take high resolution digital video and photos, which allows for the inspection of a roof or building exterior when access is extremely difficult or limited. Government regulations are still in a state of flux related to this equipment, but the rules are getting clearer as time goes on.
- Ground Penetrating Radar – The same technology that allows police to scan a field for objects buried underground is used by engineers to emulate Superman and see what is in concrete. The 3-D version can generate an image of what is embedded in a concrete slab.
Impact-Echo – This device uses a special hammer and sound waves to measure the thickness of concrete and find buried defects that are not visible to the human eye by simply tapping the surface.
Moisture Meter – Used to measure the moisture content of wood, drywall, and other building materials to help narrow down if a water leak is active and where it may be coming from.
- Boroscope – Spy movies show the hero inserting a fiber optic cable under a door or through an air vent to look into a room. Engineers use this same technology to look behind walls or under floors by drilling a small hole instead of making a large opening.
Infrared Thermometer – Allows an inspector to determine the temperature of an object without touching it. This is especially useful when checking to see if a wall is warm enough to be painted.
- Ultrasonic Thickness Gauge – Measures the wall thickness of pipes or other metal objects using sound waves to help determine if they are corroded/damaged, inside, without having to remove a piece of the material.
While technology is great, we do not rely exclusively on the digital output. The best diagnostic tools we use are still those we are born with – eyes, ears, fingers, and brain. When an engineer combines their innate detective skills with modern gadgets, we begin to resemble a human Swiss Army Knife and can arrive at a solution for your building problem
With Summer just around the corner, you may want to consider converting that unused roof area into a gathering spot with a beautiful view. Rooftop decks can be quite appealing, but before sending out the party invitations, make sure to consider these few helpful tips
- Hire a professional to specify maximum allowable occupants. Decks are designed for specific live loads (such as people, type of activity, snow, furniture) and specific dead loads (such as decking, pergola, railing). Therefore, design your deck for a specific number of people and specific activity.
- Ask your design professional about cross-bracing (lateral support), a very important building code requirement that affects the overall look of the deck.
- Study and understand exit requirements for your rooftop deck as specified in the building codes. Requirements for a multifamily residential building are more stringent and costlier than a single family home.
- Specify proper slope for water drainage. Our recommendation is ¼” per foot, although every situation should be carefully considered. Waterproofing of your deck and roof are very important factors of your project, if not properly built or maintained, it can cause problems and expenses for the residential unit below.
- Choose materials and construction details to last a long time. All framing should be pressure treated lumber and elevated above roofing material. Decking and railing material can be pressure treated or composite. Composite material is a mixture of sawdust, wood chips and vinyl. To keep it environmentally friendly, make sure the vinyl component is made from recycled plastic materials. Composite material is very low maintenance and there is no need for painting or staining.
- Pay special attention to lighting and controls, especially in areas such as stairs, change of levels and door entry/exit.
It’s hard to find a building today without concrete surfaces stained by rust. Rust stains can adversely transform the aesthetics of a beautiful building. How can rust stains be removed? Let’s find out!
Once rust staining has occurred, it is important to remove the stains without altering the color or finish texture of the concrete. Two techniques which can be implemented are dry methods (i.e. sandblasting, wire brushing, grinding, etc.) and wet methods (i.e. waterblasting, chemicals, etc.). If surface texture is not a priority, the dry methods can be a quick and cost-effective way to remove stains. If the final finish is important, as is commonly the case with architectural concrete, chemical treatments are recommended.
Mild stains usually can be removed with an oxalic acid or phosphoric acid solution, applied to a water saturated concrete surface. Deeper stains typically require a poultice, which absorbs the chemical solutions and then forms a paste over the stain. Older buildings require more attention with stain removal because the chemical treatments may remove other contaminants in the concrete, creating a lighter color than the adjacent concrete.
The rule of thumb when putting a cleaning solution on your stained carpet or clothes applies with concrete. Be sure to test different chemicals on small, inconspicuous areas to evaluate the treatment. Also, the longer you let a stain sit, the more difficult it is to remove, so seek help quickly when rust stains appear!
A glass canopy is an attractive and practical way to enhance your building entrance while also providing added curb appeal. Known as overhead glazing, an entrance glass canopy can keep the weather away and bring natural light inside the building. Here are some suggestions, if you are thinking about dressing up your building entrance with a new glass canopy.
- Keep the design of the glass canopy simple. Integrating with address, signage or building name are excellent ways to provide brand identity and marketing; but remember less is more when it comes to first impressions.
- Several factors such as weight, supports, size, wind load and location affect the selection of glass and steel supports. Glass should be high-strength tempered/laminate glass and its thickness should be specified by a professional engineer.
- Frame-less glass and minimal steel supports are attractive available design options. However, glass canopies are custom design projects. Always seek consultation services from a professional engineer who will review shop drawings, as well as assist in finding qualified contractors who have the expertise and experience to install a glass canopy.
- Specify proper slope for water drainage; our recommendation is 15% slope, although every situation should be carefully evaluated. 15% slope provides quick water drainage and glass should not deflect over time.
- Consider having a patterned glass to avoid having dust and water stains.
- Plan for gutter and downspouts. Pay close attention to ice and snow build-up and institute a maintenance program which is crucial for longer life expectancy of the canopy.
As engineers, we write allot…I mean….alot….no, I mean A LOT of reports! Check out some of the most commonly confused words. I know my editor will be glad I shared this with everyone. : )
What’s not to like about furry little critters? Squirrels are impressive, if frantic little athletes and raccoons have a certain mischievous appeal. If you take the time to observe them, birds are fascinating. But…when these little charmers invade our homes, they turn into obnoxious, destructive, noisy, fertilizer factories. They eat our soffits and clog our dryer vents. They smell bad. They become vermin that must be ousted or eliminated. It’s not entirely fair to blame them. That dryer vent or attic makes a perfect nesting site, sheltered from the elements, inaccessible to most predators with plenty of room for the youngsters to play.
Eviction is tough and extermination is distasteful; so here are some hints to help keep the critters from getting into your home.
- Inspect the building exterior for loose boards, unsealed openings and unprotected holes in the walls, soffits, etc.
- Trim any overhanging trees and remove vines and ivy from walls. These are highways for small animals like squirrels, rats or even snakes. (On the plus side, if you have snakes, you probably don’t have squirrels or rats!)
- Where appropriate, install insect and bird/animal screens at vents and openings. This can be tricky. Improperly screened dryer vents can result in reduced efficiency or even a fire hazard and screening may be disallowed in some jurisdictions. It’s also possible to reduce ventilation below acceptable levels in areas like soffit inlet if you install screening that’s too fine.
- If any new mechanical devices are going to be installed, require that they are appropriately protected with screens, guards, etc.
- Survey the building exterior and note ledges and outcroppings that are attractive to birds (look for bird droppings) and install bird repellants or guards.
- Make sure that windowpanes and screens are in good condition.
- Make sure that all ground level doors have an auto-close feature (springs, pneumatic closures, etc.). Nothing is more inviting to squirrels and raccoons than an open door.
Occasionally we run into a building owner that regards soil sampling and testing as an unneeded extra expense and asks if we can forgo this effort. Generally, soil is sampled by using a drill rig that bores into the ground up to 40-feet, or more deep. Small samples of the various soils that are found at different levels or strata are taken to a laboratory for testing to determine the composition of the soil, moisture content, and other properties.
In the field, the various soil types encountered are visually classified according to accepted standards and stiffness of the soil at different depths of the boring. These engineering properties are necessary to determine the type of foundation needed for a retaining wall or building, depth of a storm water infiltration facility, or even in the selection of a proper pavement profile.
Nearly all local municipalities will require soil testing for structural retaining walls (over 3-feet tall), storm water infiltration facilities, and buildings. We routinely obtain soil borings to help evaluate suspected building settlement conditions to learn the impact that the soil may have on the apparent building movement and help design the foundation underpinning repairs. If soil is not sampled and tested for its engineering properties, unexpected expenses can arise and the job progress can stop after the excavation begins and unsuitable soil layers are found.
It goes without saying that engineers aren’t known for their fashion sense or style, but no matter what profession, it can often be difficult to decipher the meaning of a dress code. There is no need to arrive at your next event wondering if you got it right. Below is a run-down by the common US dress codes and what they mean. Now even engineers can be appropriately dressed….well maybe : )