· by Michael Blair, Nashville's Garage Door
Most people who search for garage doors for sale are comparing styles, colors and windows, and that is the right place to start. What the showroom rarely explains is that the door is one part of a working assembly. The springs above it are sized to its weight, the opener is set to how it travels, and the safety sensors and reversal test are tuned to where it stops. Swap the door and every one of those has to be checked again. This is what changes when we hang a new garage door in place of an old one, and what to ask whoever sells you yours.
The springs belong to the old door
A garage door is not lifted by the opener. It is lifted by its springs, which are wound or stretched to offset the door’s weight so that the opener, or a person, only has to guide it. The Door & Access Systems Manufacturers Association says so directly in its technical data sheet on adding weight to a door: doors are engineered as complete systems, and the springs are chosen for the weight of the door they came with. The same sheet puts residential and commercial doors anywhere from about 90 pounds to more than 500.
That range is the reason the old springs rarely suit a new door. A replacement with a different construction, an added layer of insulation, glass in the top section or carriage-style overlays may weigh noticeably more or less than the plain panel it replaces. DASMA lists what happens when weight and springs do not match: the door goes out of balance, springs break early, the opener is overworked, the door can come off its track, and the warranty can be voided. Springs already have a limited number of cycles, as we cover in how long garage door springs last, and a mismatch only shortens that.
So the first question about any door for sale is not the color. It is whether the price includes springs sized for that door, installed with it, rather than the old ones reused on a door they were never meant to hold.
The opener has to be set and tested again
An opener stores where the door stops at the top and bottom and how hard it may push before it treats resistance as an obstruction. A new door travels and weighs differently, so those settings start over. The federal standard behind every opener, 16 CFR 1211, which the Consumer Product Safety Commission’s 2018 rule in the Federal Register ties to the UL 325 entrapment requirements, expects a closing door to reverse when it meets something in its way.
DASMA’s guidelines for dealers and installers on opener legislation spell out what that means on the job. Openers made on or after January 1, 1993 must reverse within two seconds of contacting an obstruction and must carry a secondary protection, such as a photoelectric eye or an edge sensor. The installer is to test the auto-reverse whenever a door, an opener or its hardware is installed, serviced or repaired, using a 1 inch or 2 inch block laid flat under the center of the door as the opener’s manufacturer specifies, write the result down, and show the owner how to repeat the test each month. If the door cannot be adjusted to pass, the owner is to be told out loud and in writing.
The photo eyes may need to move too. DASMA’s sheet on photoelectric sensor placement puts the lowest lens beam no higher than six inches above the floor and the sensors within six inches of the door’s path. A new door with a different track setup or a thicker bottom section can leave old sensors in the wrong spot.
Keeping an older opener is not against federal law, which governs how openers are made rather than whether an old one can be reinstalled, and DASMA notes that only a handful of states, none of them Tennessee, have installer rules of their own. The same guidelines also say DASMA does not support installing old or non-compliant units. If yours has no photo eyes, a door replacement is the natural time to settle that, and our notes on chain, belt and direct drive openers can help with the choice.
Parts that look the same are not always the same
When a door is replaced, there is a temptation to keep whatever still looks good: the tracks, the hinges, the brackets, the bottom fixture. DASMA’s technical data sheet on component substitution warns that a part can match another in appearance and differ in strength or thickness in ways no one can see, and that mixing non-identical parts into a door tested or rated for wind load can weaken the whole assembly.
The practical reading is that a new door should come with the hardware its maker designed for it. If a seller proposes reusing old tracks or brackets, ask why, and ask whether the door’s manufacturer allows it. A quote that looks low because it leaves old hardware in place is pricing a different door assembly than the one in the brochure.
- Springs sized to the new door’s weight, not carried over
- Tracks, hinges and brackets from the door’s own maker
- Opener travel and force set for the new door
- Photo eyes checked for height and position
- Auto-reverse tested, written down and shown to you
Permits, paperwork and the questions to ask
In Davidson County, Metro Codes’ list of projects that may or may not need a permit for one- and two-family homes marks a door replacement where the opening does not change as needing no permit, and a new or relocated door as needing one. The list has no separate line for garage doors, so if you are widening the opening, going from two single doors to one double, or moving it, call Metro Codes before the work is booked. Outside Davidson County the rules belong to each city and county, so for a door in Murfreesboro and the rest of Rutherford County, or anywhere else in Middle Tennessee, ask the local codes office the same question.
Whatever door you buy, the manufacturer’s written materials should stay with you. DASMA’s installer guidelines call for leaving them with the owner, and they hold the spring warnings, the opener settings and the warranty terms you will want later.
When you compare doors for sale, put the same questions to every seller. Will the springs be sized for this door? Will the opener be reset and the reversal tested and recorded? Will the hardware be the door maker’s own? Is the opening changing, and if so who handles the permit? If you would like those answers for your own garage, ask us for a free estimate and we will look at the opening, the opener and the door you have in mind together.
Sources
- DASMA TDS #176, Adding Weight to a Garage Door Assembly — Doors engineered as systems; springs fit the original weight; doors weigh from about 90 to over 500 pounds; what a mismatch does
- DASMA TDS #351, Federal and State Residential Garage Door Operator Legislation Guidelines for Dealers and Installers — Two-second reversal and secondary protection; auto-reverse test at every install or service; leave manufacturer materials with the owner
- DASMA TDS #364, Installation Location of Photoelectric Sensors on Residential Garage Doors — Lowest beam no higher than six inches; sensors within six inches of the door path
- DASMA TDS #183, Garage Door Component Substitution — Look-alike parts may differ in strength or thickness; risk to rated doors
- Metro Nashville Codes, List of Building Projects Which May or May Not Require a Permit — Same-opening door replacement: no permit; new or relocated door: permit
- Federal Register 83 FR 32576, CPSC rule on 16 CFR 1211 — The opener standard incorporates UL 325 entrapment protection