Author Topic: Garage door questions  (Read 3557 times)

tannybrown

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Garage door questions
« on: July 04, 2012, 11:26:07 AM »
So our first home, built in 1950, has a very old, very heavy steel garage door, with one spring's cable snapped.  The style of the spring system is antiquated, as it runs a metal cable over a system of pulleys on each side of the door.  We're not using the door as it's a safety issue, with all the door's weight on one cable.  I had a few questions:

-We were going to hire out a contractor to do a torsion spring conversion ($300) as working with springs under tension seems pretty dangerous for someone without proper knowledge.  What do you think? 

-I want to install a garage door opener myself once the springs are installed.  There's a large wooden beam that I believe I can frame something onto, and then attach the garage door opener to that.  Is this a DIY project one can fake their way through?  The door has never had an opener attached, so the connection between the chain and the door is the one part that has me worried...maybe it's just as easy as attaching some metal screws though.  However, from a Mustachian perspective, should I just get out of the car and open the door by hand?

-If an opener is the way to go, how much HP?  I believe the springs do most of the work when lifting, but as the door is heavy, I don't know if the cheaper 1/2 horsepower will suffice.

nevinera

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Re: Garage door questions
« Reply #1 on: July 04, 2012, 06:11:32 PM »
Maybe Your door isn't what I picture, but are the springs under that much tension when the door is raised? You should be able to open it fine with one (or no) springs, as long as you have sufficient muscle, and dont stand below it, yes? If the weight is really frightening, you could shove something sturdy below it so it can't fall all the way closed.

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However, from a Mustachian perspective, should I just get out of the car and open the door by hand?

From a strictly Mustachian perspective, your bike should fit through the side door ;-) But yeah, I'd say an automatic door opener is one of those stache-trashing conveniences you could do manage alright withou.

gooki

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Re: Garage door questions
« Reply #2 on: July 04, 2012, 06:45:45 PM »
At the same time assuming you want to sell your property one day, then installing a garage door opener should pay for itself in increased capital value/faster sale time.

tannybrown

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Re: Garage door questions
« Reply #3 on: July 04, 2012, 07:10:57 PM »
Maybe Your door isn't what I picture, but are the springs under that much tension when the door is raised? You should be able to open it fine with one (or no) springs, as long as you have sufficient muscle, and dont stand below it, yes? If the weight is really frightening, you could shove something sturdy below it so it can't fall all the way closed.


So the style has two springs with each rated to handle 1/2 the weight of the door.  But on one side, the cable has snapped so the spring on the other side is now working twice as hard as it's meant to...not good to open and close the door currently from a safety perspective.

nevinera

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Re: Garage door questions
« Reply #4 on: July 04, 2012, 07:23:02 PM »
If its a normal door, and it sounds like it is, those springs are under full load while the door is closed. They don't operate the door, they counterbalance it. Having only one spring means that you will have to do a lot more work to lift the door in the first place, and you should probably do something to keep it from falling back down after its lifted, like putting a bookcase or 2x10 against the rail..but it's not like operating the door is less safe than lifting any other heavy object.

If your concerns are about the falling door, then (a) don't go under it while it's raised to replace the spring and (b) stick a couch cushion under the place the door would hit on the ground (this is just to keep the door from hitting so hard that the windows break if it should slip).

The spring is not working 'twice as hard', it's doing exactly the same work as usual. It's you doing the extra work, not the spring :-)

tannybrown

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Re: Garage door questions
« Reply #5 on: July 04, 2012, 07:26:10 PM »
So the remaining spring isn't under extra load without the other?

nevinera

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Re: Garage door questions
« Reply #6 on: July 04, 2012, 07:37:07 PM »
The amount of force a spring provides is a function of how stretched it is, in terms of distance. You can't think of it like a machine towing your door up it's rail; it's more like a counterweight, intended to make the door light enough to easily move.

One spring being gone means the door is effectively about half it's actual weight, instead of weightless, which is why you will need some serious muscle to do the lifting (don't do this solo unless you're burly and know how to safely lift stuff).

How difficult detaching/replacing that spring is once the door is lifted depends on how much tension it's at at it's loosest (at the top) and that can vary. I've replaced one of mine before though.