I didn’t originally answer this question because I wasn’t sure, but I had a close look today. It’s not exactly wood – it’s MDF (medium density fiberboard) with steel or aluminum cladding on the outside and some wood reinforcement on the inside. It’s probably pretty heavy but when I had to open it manually once during a power failure it was very easy because of the compensating springs.
It’s a similar idea to my exterior doors which have a solid wood core and steel or aluminum cladding on both sides.
The rod broke well to the side of the spring (which takes up maybe 1/3 of the width of the rod), and the spring itself didn’t unfurl or anything. Such unfurling would, indeed, have released a lot of force and probably some part of the door would have been chewed up or something.
There seems to be some disagreement in this thread on this point. The counter-assertion is that the spring itself counterbalances the weight of the door all the time (there is constant tension put on the spring, which is why sudden release can be so dangerous), so that the weight being lifted (by the motor) is roughly the same for all types of doors.
So wear and tear, yes. Heavier door making the spring hardware work harder, maybe not. Our rails are quite clean, since they are inside the garage and are only exposed to the elements briefly when the door is in use.
That California law is astonishing. I’m a good liberal, one might even say a Big Government Liberal, but I thank God I live in a state that would resist such a law on libertarian principles. Looks like those batteries run only $50 or so, but they have to be replaced every year or two. (One random installer’s webpage crows about how long-lasting this is.) Of course It’s not the supplies, it’s the maintenance. Who wants to have professional maintenance performed on their garage door every year or two?
Well, I tried to avoid complying as long as possible, and eventually needed my garage door working for a lot of reasons – including parking the car in the garage. I haven’t had any problems with the door or the battery back-up since then, but it’s only been four years and a few intentional brief power-outages when So Cal Edison was upgrading equipment. In fact, I just got a notice saying they’re planning to do another upgrade at the end of the month so I should expect a 15-minute outage around midnight.
Guessing from the parts website that I got my replacement pieces from, different manufacturers and models require different dimensions of bar and spring and (sometimes) cable. The cable drums looked pretty universal, but I might not have been paying close attention. There was even a part of the site that would let people enter certain dimensions if they couldn’t find brand names and model numbers on the hardware. Critical issues were the diameter of the torsion bar (pipe) on which the springs were mounted, and also the diameter of the metal of the spring and the diameter of the cross-section of the coil. Thicker metal wound tighter obviously makes an extremely powerful potential energy; a heavier door would call for a thicker/stronger coil.
In the kit I bought there were two 18" long steel bars% that get inserted into little holes on the drum attached to the spring. Set one and lock it in place, loosen a bolt, then set the other bar in the next hole on the drum. Torque a little to release the first bar, and ease that second bar around to loosen the spring by a partial turn. Lock that second bar in place and set the first bar in the next hole. The critical part is to count the ‘steps’ until the drum is slack and write that down (I used a sharpie right on the wall above the garage door so it would be big, bright, and wouldn’t fall off and get lost somewhere). Then I had to repeat the process on the other spring (some doors have two, some have one). Then I could loosen the cable drums, slide the old coil-springs off and slide the new ones on and tighten them, and lock a spring-drum in place. Then came the tedium of tightening the drum step-by-step (making sure the count was correct) with the steel bars and tightening the bolt to lock it in place. Repeat on the other side, in my case.
Even I will encourage leaving that change to the professionals, though. It really isn’t rocket-science, but the cost of disaster can literally be someone’s life. I was lucky in that my only accidents occurred when I was hasty in letting my hand release a bar before I was certain the torsion was pressing it in place against the wall. Twice I had a bar fall out of its hole and had the other bar come spinning around and knock me under the chin@. Both times left stupid-looking bruises and the second one even made me chip a tooth. Had I been so hasty when turing that drum in the other direction, I would have gotten pretty strong knocks atop my forehead.
–G!
%With no more use for those tools, I didn’t just throw them away. I’m a packrat so I saved them for the one-in-a-billion chance I might need a steel 18"x .5" rod for some project or another – and, at some point I actually used one!
@Fortunately, that wasn’t the first time I’d taken an upper-cut. I was just a little off-guard because I wasn’t sparring with a person.
The professional I hired to redo our garage door recommended I not be in the garage while he was doing the springs. He’d been in the business for a couple of decades. I went golfing!
I replaced a broken spring on a wooden roll up garage door myself. Pretty easy, install the spring while the door is up, make sure it closes easily and adjust the tension a little at a time until the door closes under it’s own weight but still rolls up with normal effort. Best to test the door from the outside and keep your head away from windows in the door in case something else gives under the tension of a new spring.
The technician came yesterday and replaced the rod, spring, cables and cable reels, it took him less than an hour. I probably overpaid for this, but I’m glad it’s done. I really dislike going in and out of the house by the front door (the only other option to the garage) because the stairs are concrete and curved, and you have to stand on the inside of the curve, where the steps narrow down to nothing, when you’re putting the key into the security gate.
Today, my garage door ran past the “down” limit switch and sort of crashed. Of course I didn’t notice this when I was leaving in the morning, but when I got back from work, it wouldn’t open. I had to get in through the side door and undo the linkage that connects the door to the carriage, slide the carriage back to the proper place and re-connect. This is the second time it’s done this in the 15+ years I’ve had it.
