Garage Door Words Franklin Homeowners Hear

The vocabulary on a garage door job arrives from three directions. Some of it gets said out loud in the garage while somebody is pointing at something: balance, backroom, headroom, high lift. Some of it is printed on a spec sheet and decides what you are buying: gauge, cycles, R-value, wind load. And some of it appears only on the paperwork, which is where astragal, jamb and drum tend to catch people out. This page settles all of them in one sentence each.

The practical use of it is comparison. Two quotes for the same door become comparable the moment you can read the specification lines instead of the totals, and a vague quote gives itself away the moment you know which lines are missing. A spring quoted with no cycle rating against it. A door quoted with no gauge. An insulated panel quoted with no R-value. Those are not oversights. They are the numbers that would have made the price look different.

And if a word on your estimate is missing from this list, ask before you sign. Anyone doing the work properly can put it into one sentence without sounding bothered, and the answer tells you as much about them as it does about the door.

Every Term, Alphabetically

Astragal

What an estimate means by the bottom seal: the rubber or vinyl strip that squashes onto the slab. Once it hardens and splits you get daylight, drafts and water at the door line.

Backroom

The measurement that decides whether an opener will fit at all. Clear depth from the opening back into the garage, needed for the horizontal track and the rail behind it.

Bottom bracket

Holds the lift cable to the bottom corner of the door, so it stays loaded even with the door flat on the slab. Unbolt one and the spring's stored energy comes out through it.

Cable drum

Set the pair of these unevenly and the door lifts crooked. Each is a grooved wheel on the end of the torsion shaft that winds its cable on as the door rises.

Center bearing

A chirp once per turn of the shaft is usually this, run dry. It is the bearing at the middle of the torsion shaft, carried by the spring anchor bracket above the opening.

Constant-contact control

One of the two ways an opener is allowed to meet the secondary protection rule. A wall button that closes the door only while held down, and sends it back up when released.

Counterbalance

The springs, cables and drums that carry the door's weight so the motor only fights friction. Test it by hand with the opener released: a balanced door stays put at waist height.

Cycle rating

The number on a spring quote that decides whether it is cheap. One open plus one close is a cycle, so a 10,000-cycle spring is about seven years at four a day, or one at forty.

Down force

The setting turned up to make a binding door close, which cancels the protection it exists for. It governs how hard the opener pushes down before deciding it has hit something.

Emergency release

The red cord you pull when the power is out. It uncouples the door from the opener carriage so it can be worked by hand, and it should only be pulled with the door fully down.

End bearing plate

Where a slack cable usually ends up jammed. One is fixed to the framing at either side of the opening, and the bearing it holds is what the torsion shaft spins inside.

Entrapment protection

What you are testing when a block of wood goes under a closing door. Openers have had to reverse on contact since 1991, with a second layer of protection required from 1993.

Extension spring

Turns up on older single-car garages, mounted alongside the horizontal track and stretching as the door comes down. Each one needs a containment cable so a break cannot throw it.

Full-view door

Glass or acrylic in an aluminum frame instead of solid steel sections. Heavier than steel, so the counterbalance is specified for it, and fitted it runs an estimated $2,850 to $6,400.

Gauge

Steel thickness counted backwards, so 24 gauge is thicker than 27. Builder-grade doors are usually 25 to 27 and mark easily; 24 is what a quote means by a heavier skin.

Header

The beam over the opening that the spring anchor and the opener's front bracket both pull against. Movement or rot up there shows up as a door binding near the top of its travel.

Headroom

Decides which torsion setup is possible: the clear height above the opening up to the ceiling. Tight, and a quote will call for a low-headroom kit or an opener mounted on the wall.

High-cycle spring

Heavier wire wound to a longer body, rated 20,000 to 25,000 cycles instead of 10,000. An estimated $60 to $120 more per spring, and worth it on any door used as the front door.

Hinge

Elongated holes in these are why a section sits crooked. Each stamped plate joins one section to the next and carries a roller, and they are numbered by position on the door.

Jackshaft

The answer when the ceiling is full or storage racks are in the way. The opener mounts on the wall beside the torsion shaft and turns the shaft directly, with no rail overhead.

Jamb

The framing each side of the opening that the vertical track bolts to. Out of plumb, rotten at the base or badly shimmed, and the whole door runs crooked along with it.

Learn button

Hold it too long and every remote, keypad and car button has to be paired again. It is the small button on the opener head used to teach the unit a new transmitter.

Lift cable

Half the door's weight hangs on roughly an eighth of an inch of aircraft wire, tied to the bottom bracket and wound onto the drum. Replaced in pairs, since both have aged together.

Photo eye

The reason a door reverses when a bin is in the way. Two sensors face each other about six inches off the slab, one sending an infrared beam and the other watching for it.

R-value

Measured through the door panel, not across the opening, so it is not the same as a sealed garage. Higher resists heat flow better, and it says nothing about the gaps around the door.

Radius

Quoted as 12 or 15 inches: the curve where vertical track becomes horizontal. Two different radii on one door will make it snatch at the same point on every cycle.

Roller

The wheel on a stem that carries the door round the curve of the track. Nylon on sealed bearings stays quiet for years; plain steel gets noisy and wears flat spots.

Rolling code

Why nobody can record your remote and use the signal later. The code changes with every press, and openers have worked this way since the mid-1990s.

Section

One horizontal slab of the door, four or five of them stacked to make the whole. When a quote replaces a single section, the track, springs and other panels are all staying.

Stile

The vertical rail up the edge or center of a section that hinge screws bite into. Once one works loose the fixings have nothing left to hold, and that door is near the end.

Strut

Bolted across the face of a section to stop a wide door bowing as it lifts. It also stiffens the top section where the opener arm pulls, which is where flexing does the damage.

Threshold seal

Bonded to the slab in the opening rather than to the door, so it works where the concrete has settled or slopes and the bottom seal on its own can no longer bridge the gap.

Torsion spring

Stores the energy that lifts the door, twisting on a shaft above the opening rather than stretching. Loaded even with the door down, which is why it is never a homeowner job.

Track

The steel channel the rollers run inside. Once it is dented at bumper height, spread at a seam or leaning off plumb, it fights the door rather than guiding it.

Travel limit

Tells the opener where the slab is and where the top of the travel is. When a door parks an inch high, or presses hard into the floor, this is what has drifted.

Trolley

Rides the opener rail and pushes the arm that moves the door. The red release cord uncouples the door from it, which is the whole reason the door can be worked by hand.

Winding bars

The only correct tool for winding or bleeding a torsion spring: two solid steel rods that fit the cone holes exactly. Anything that can slip out under load is how people get hurt.

Wire diameter

One of four readings taken off an old spring before a new one is ordered, with inside diameter, length and wind direction. The thickness of the wire, in thousandths of an inch.