Overhead Door Repair and Installation             Doorsmith Logo                         

Overhead Sectional Doors

The commercial application of overhead sectional doors is seen abundantly.  Generally, a stack of 2' tall panels are hinged together.  Rollers are at the outer hinges, which travel through track, or safety track. Rollers can be 2" or 3". They should always be long stem safety rollers. A lot of doors do not have them originally. If a door becomes too much out of alignment, by say, a broken cable, being hit by a forklift, having a drum slip, or forcing operation when the door is jammed, short stem rollers can pull right out of the hinges. The entire door can fall.

Above all, it cost a lot less to fix a door, than it does to fix a person. Safety track is of heavier gauge, and is configured to make it even more difficult for the roller to be removed. A good example would be of those seen on one piece counter balanced overhead doors.

Door travel falls into three types:

Standard lift

Hi lift

Full vertical lift

A standard lift track has the track radius below the header, with the horizontal track at header's level.

Overhead track is vulnerable to forklift traffic. Hi lift track has the track radius a distance above the header.  This helps door equipment become less exposed.

Full vertical lift track lets the door travel straight up the wall. Torsion assemblies are located above track radius.  Consider door repair technician accessibility when building around door equipment.

A bent shaft can be caused by a number of things. Light gauge hollow shaft is the least desirable, though more economical. Torsion tube is another term for this type. I would specify a minimum of 11 gauge shaft when using hollow shaft. Hollow shaft does allow for good set screw penetration, and bite. Solid shaft is used for heavier applications. It will make use of keyed shaft, using 1/4", or 5/16" key stock to secure positions of the drums.

Spring calibration affects door travel. It should also be checked that  the last 'technician' didn't re-use the torsion assembly from a previous door, with different weight / door travel characteristics. Spring calibration considers the weight of the door, the travel of the door, and the type of door travel.  A spring conversion is sometimes used during spring replacement. When having a broken spring replaced, replace all of the springs. The other springs are just as fatigued. Disassembly of the torsion assembly would only have to be considered, once, if you replaced them all at the same time.  A properly trained technician will lubricate torsion assemblies, to minimize spring fatigue. He will also make sure set screws and hardware are secure. Spring tension should be properly adjusted to match door travel.  The door should be able to just hold itself up, when in the open position. If the door drifts downward, from open position, it exposes the lower panels to forklift traffic. If the door flies upward, an abrupt stop is met at the end of door travel.  This scenario will cause hardware to loosen, and wear out. The rollers can also come out of the track. The top sections will show damage at the top fixtures where, hopefully, it is, at least, making contact, with bumper springs.

Bumper springs help cushion the end of upward door travel. They also keep positive tension against the cables, and help prevent cables from falling off the drums. Push down springs can also keep positive tension on the cable. These can allow for more cushioned travel, and are helpful, when an electric hoist operator tries to negotiate the track radius with the bottom panel.

Bottom fixtures require special attention. DO NOT mess with them. They are connected to a cable loaded with kinetic energy. They need to be secure, and in good condition.

Cables need to be in good condition, without frays, kinks, or unwinding. The nicro-pressed sleeves of these cables should have been properly squeezed during previous installation.

Rollers rated for 10,000 cycles are available. The cost considerations are insignificant. Steel rollers can easily have the shoulders ground, for one piece door applications. Nylon rollers can limit noise.

Noise can often be a consideration. 11 gauge hinges are available, which are sure to help the creaks. Gear head operators are definitely of the industrial grade, but are remarkably quiet. Sectional panels can be constructed of steel, wood, or fiberglass / plastics. They can be insulated, and made to reduce noise.

There are products made for ready retrofit, and break away designs, to consider forklift traffic. Special bottom fixture designs, are available, to help prevent the door from dropping, in the event of cable failure, or, spring failure. There is a handy, spring loaded, tear dropped shaped "roller", that locks itself off when it mechanically senses release of cable tension. Some bottom fixtures have a cable tension design, that helps maintain proper cable feeding onto the cable drum.

Trolley operators are quite useful for overhead sectional doors, as the operator stays connected to the top section, rather than the shaft.  Reversing devices help detect obstructions, but nothing is fool proof. A hoist operator can turn the cables right off the drums, if it fails to detect an obstruction. Everything has their considerations, choose the right applications.

Canopy Doors

Everyone would recognize a typical one-piece door at a residential garage, which would be termed as a half canopy door. If it were hinged at the header, it would serve the function of a full canopy door.  This would provide maximum shade, but alas, wind causes potential operating hazards. You might see aircraft hangar doors using this application, but in a much more heavy duty sense, as compared to, the style of full canopy door you might find at an RV repair shop. Aircraft hangars can utilize bi-fold doors, and some of the most interesting hybrids in between.

Counter Balance Doors

A one piece overhead counter balance door uses a weight can, cable, a series of pulleys, and rollers contained within track. The one piece panel typically rides above the floor space inside of the opening. Multiple panels can be used in a full vertical lift application.

Maintenance items

We offer maintenance that includes the following:

  • Lubricate all points of friction
  • Check counterweight balance
  • Inspect torsion assembly
  • Inspect bearings for damage or wear
  • Inspect panels and track for alignment
  • Inspect and tighten all loose hardware
  • Inspect cables for frays or damage
  • Inspect rollers for damage or wear
  • Inspect lock hardware for damage and proper engagement
  • Inspect sheeting for looseness or damage
  • Provide recommendations for improvement and/or safety items
  • Provide a written assessment of the door
  • Provide a quote for additonal improvements or repair, if needed

A standard maintenance cycle is recommended every 6 months, more frequent cycles are available for high traffic doors, or insurance needs.

 

Doorsmith, Inc. is an overhead door repair, and installation, service that proudly serves Orange County, California. We find strength in communication, and awareness.

updated: 11/01/11