Whether you know it or not, our industry products are entrenched with specifications, or “specs.”
Specifications describe a product’s rating or how much work it can do. Architects sometimes request custom products by submitting their own specs for a particular job. Most architects, however, are unfamiliar with garage door automation and regularly submit contradictory specifications, creating requests for redundant systems. As a result, it’s hard for us to find a set of architectural specifications for a job not requiring follow-up questions.
I always have a good laugh when an architect requests a dead man’s switch, which requires constant pressure on the door close button. The term dead man’s switch dates to the 1850s, when it was required on steam-powered locomotives. Locomotive builders feared the damage a runaway train could cause, so they built a cockpit lever, requiring action from an engineer, to transfer steam to the drive pistons. If the engineer pulled the lever, the train would go, but if he released it—because he got shot by an arrow or, more likely, fell over drunk—the train would stop. This mechanism isn’t the same as pressing the close button to close a door, but the same principle applies.
It’s important to share any architectural specifications you receive with your manufacturer, especially when safety is in question. This ensures that you only install a product that meets the requested specs! If an architect finds a discrepancy during his inspection, you’ll have to start over at your own cost.
This leads me to another tip. If you’re a door dealer and receive an architect’s specification sheets, do yourself a favor and forward them to your door provider or commercial door operator vendor. CDO manufacturers have dealt with difficult architectural specs for many years and can understand their complexity easier than you can.
Garage Door Specifications
Garage doors used to have simpler specifications, but as doors improved and wind-load standards kicked in, these specs have expanded. Traditional wooden garage doors may have had a minimal number of specs, but the development of steel garage doors brought on new specs like steel gauge and insulation values, usually between R7 and R14.
A garage door will generally be stated as 1.75 inches thick and must offer a specific insulation. Some manufacturers produce 1.375-inch-thick doors that provide less insulation, while others go up to 3 inches thick. A 3-inch-thick door that has a higher R-factor indicates a greater insulation value.
Then there’s the U factor, which describes how effective the overall system is at deflecting air infiltration. Door manufacturers have been starting to display their door’s U factor, and I imagine this specification will soon join the rest of the standard garage door specs. The door’s weather seal and bottom rubber performance must be considered in U factor specifications, so even installers have begun to feel pressured to perfect their weather seal installation. While this is something to prepare for, testing and evaluation for U factors aren’t even on the drawing board yet and are only now being given focus. Because of compliance complexities, the need to pay this spec attention is likely still 3-5 years or more away.
Some more important specifications to keep in mind are the outside door skin gauge and steel skin thickness. Most steel doors use a less costly 26- or 24-gauge, where a more robust door can feature up to a 20-gauge.
Wooden doors were preferred in Canada due to their ability to deflect a hockey puck, but when aluminum and lighter-gauge steel doors were introduced, they were used more commonly. I have personally seen doors marked with hundreds of scuffs and dents!
Devastating hurricanes and extreme windstorms have forced our industry’s door manufacturers to develop stronger doors to withstand extremely high winds. Wind loads have been a common specification since 1980, when Hurricane Andrew destroyed numerous homes in Southern Florida. It was determined that the damage to homes began when positive winds pushed garage doors into homes or negative pressure sucked doors out of their garages. With no doors in place, high winds entered garages and lifted roofs off houses, causing interior and exterior walls to fall. The blame was not only aimed at the garage doors, but at county inspectors and builders who ignored an important specification. It was their duty to ensure that roofing struts were secured with metal straps to each corner of the cement foundations so that high winds couldn’t lift the roofs. Today, garage doors are built to withstand high winds, either with tougher construction or stronger steel bracing. This story represents how important it is for specifications to be observed and followed!
Door Hardware Specifications
Tracks come in 2- and 3-inch configurations, with expanded specs available in different gauges to handle higher-weight door sections. These expanded specs may prevent destruction of property from positive or negative wind loads. Weaker vertical tracks have also been known to fail during high wind events. All garage doors sold in Florida after 2001 were required to include extra bracing to prevent the panels from bowing inward or outward. Hinges are also available in heavier gauges, with some made in 11 gauge (nearly 1/8 inch thick). Rollers are also made in 2- and 3-inch varieties, with 3-inch rollers having the best record of endurance. If you want to supply a kick-ass system, start with a 3-inch track.
When engineers are considering track formations, their specifications are recorded similarly to the measurements of a shoe. If you measure between the inside toe and the inside heel of the track, it should be less than 2 inches. Make sure that the roller flows freely through the track radius. When a track is bent to form the radius, it is common for the track to close a bit. When I first began assembling commercial tracks, it was important to test the track radius with a roller. It didn’t happen often, but there were times when we had to adjust the tooling in the roll-former or replace the snake that was used to bend the track. Decades ago, it was determined that more tolerance was needed, so buffers were incorporated into designs.
As we can see in every other industry at the moment, manufacturers are starting to use lighter metal to cut costs. If you did find an exact 2-inch roller, it very likely wouldn’t even roll through a 2-inch track at this point. I once worked with a Chinese company that produced sample two-inch rollers, and they were upset to discover that they didn’t operate in our two-inch track!
Let’s not forget about the springs. The wire size, inside diameter, overall length, and handing (left or right wind) are important measurements to keep in mind while ordering replacements. Every service person must be aware of spring specifications!
Commercial Door Specifications
Since door and gate operators are electrical-mechanical machines, they will require the most specifications. Commercial door operators can be used in numerous door applications or variations, so a manufacturer may produce up to 15 models of commercial door operators. When you factor in the 7 voltage choices and the 5 different horsepower motor choices, a manufacturer could build over 250,000 variants of operators. Once you factor in the 200 options and NEMA choices, the number then jumps to 500,000 variants. The sticker on the operator cover must display essential specs like the model, motor HP, voltage, current draw (amps), phase, and frequency (Hz) so that the electrician can run the correct voltage and employ the correct wire gauge.
Other important specs will show the operator torque in ft-lbs and the date of manufacturing. I don’t believe anyone other than operator engineers ever calculates how many ft-lbs of torque are needed to open a specific door, but manufacturers of operators must include the torque to meet a requirement in the UL 325 safety standard. Just so you know, manufacturers are obligated to build their operators to produce the necessary torque to lift the common range of doors.
If a door dealer ever called me and asked for an operator that could produce a certain number of ft-lbs or newton-meters of torque for a specific door, I might fall from my chair with shock. The ft-lb rating is there to prove that the operator complies with specifications for torque, but this spec should only be a concern for designers.
It doesn’t end there, either. Inside a door or gate operator, you may find 50 electrical components, not including the electrical motor, that also display their own detailed specifications and ratings!
Miscellaneous Specifications
Door accessories, control stations, and entrapment protection devices also require unique specifications. There’s no doubt that an electrical machine will be bamboozled with specs, but you must decide whether they concern you or not. There is so much more to learn to be truly proficient in our industry, so you may choose not to deal with all the specs. That’s okay; manufacturers own that task! Any time you need more information, you can rely on people like manufacturer tech support workers or me to help you out. NOW GO GET EM!