OVERHEAD garage doors that roll up in hinged sections or panels are far more popular than the one-piece, canopy-type doors, even though one-piece doors are generally cheaper. Sectional doors are more reliable and less likely to break down or need frequent adjustment. However, spring tension will have to be increased eventually, and rollers or other moving parts will need lubrication or tightening.

All the panels in a sectional overhead door are joined together with hinges. The end hinges have rollers attached to them, and these rollers move along the inside of tracks that are mounted to the garage door frame on each side of the door. The tracks run up vertically on each side to a little above the top of the door, then continue horizontally back inside the garage, as illustrated in the drawing.

Most overhead sectional doors of this type have two large springs, one on each side, that serve to counterbalance the weight of the door so it can be easily opened by anyone, and so it won’t come crashing down uncontrollably when you start to close it. If the door is properly balanced and the springs properly adjusted, you should be able to lift it about three feet off the ground and let go. It should then start to sink slowly back down – or it may just stay where it was when you released it. If it falls rapidly, or if it starts to fly up by itself, then the spring tension needs to be adjusted.

All springs lose tension as they age, so it is only natural that they will require some adjustment to increase tension after a few years of normal wear. Also, wood doors tend to absorb moisture, which adds to their weight, and each time the door is painted, several pounds more weight are added on – all factors that change the amount of tension needed. And sometimes springs break entirely, so they must be replaced (always replace both springs even if only one is broken, otherwise the door will be unbalanced).

Unlike the one-piece doors described in last week’s column, sectional or roll-up doors like the one illustrated here have the springs mounted overhead. They extend horizontally alongside the tracks on each side, with one end of the spring attached to a metal bracket or hook on the far end of the horizontal track. The other end of the spring is attached to a pulley over which a cable travels.

One end of this cable is attached to a bracket at the top which has a number of adjustment holes in it (for shortening the cable when desired). The other end of the cable is attached to the bottom of the door on each side after traveling over another fixed pulley that serves as a guide.

One of the most common problems with doors of this type is that the cables jump off one or more of the pulleys over which they travel, so check this first if the door does not work smoothly. If inspection shows that the cables are all right, then check the rollers that are attached to the door hinges to see if the mounting bolts that hold them in place are loose. This will cause the rollers to wobble inside their tracks and can cause binding or sticking in places.

The same holds true if rollers need lubrication, or if tracks are clogged with dirt and debris, so check all these items before assuming that the springs need adjusting.

When spring tension does have to be increased because the tension is no longer strong enough to counterbalance the weight of the door, the first thing to do is raise the door as high as it will go, then prop it open with a long board braced against the floor, or by wedging blocks inside the track. The springs will now be under practically no tension because the cables to which the springs are attached will be slack or almost slack. To increase tension in the springs, you have to shorten these cables so as to stretch the springs more while the door is all the way up.

Adjusting Sectional Garage Door

On most doors, the cable ends are attached to the brackets at each side in one of two ways: either the cable goes through one of a series of holes and then is secured there with a knot, or the cable will be attached to a large S-hook that fits into one of a series of adjustment holes in the bracket.

To shorten cables (and thus increase tension) on those that are knotted, simply cut off the knot, then shorten the cable by the amount required and tie a new knot to hold it in place. To shorten those that are attached with an S-hook, pull the hook out and move it over one or two holes until you have stretched the spring by the desired amount. If the hook is already in its last hole, then the cable may have to be cut shorter. Just remember that when you do this, you are dealing with powerful springs that can exert quite a bit of tension, so exercise caution and wear heavy gloves while working with cables, pulleys and springs.

Sometimes, no matter how much you shorten the cable, the tension will still be too weak. If this happens, it means that new springs are required. They are sold in many hardware stores, home centers and lumber yards.

Some sectional or roll-up type doors have a single large torsion spring across the top of the door, instead of a pair of tension springs on each side as described above. Torsion springs are wound up like a window shade spring, instead of being stretched like a tension spring.

This type of torsion spring is under extremely high tension and must be wound up (when necessary to increase tension) by using a heavy metal bar that fits into a hole in one end of the spring barrel. This can be dangerous, especially if the bar accidentally slips away from you. That’s why tightening this type of spring is no job for amateurs – it calls for extreme caution, special tools and a considerable amount of skill. A professional garage-door serviceman should be called in to do the job.

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