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Garage door tracks

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#1 Simply Peter

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Posted 23 June 2022 - 09:03 AM

I bought sky shed plans for a ROR observatory.  The plans call for metal roofing.  I have changed direction and plan to use a BZB cabin kit which assembles similar to lincoln logs.  The kit supplies material for a roof with 3/4" thick roof boards to be covered with shingles. Will the garage door rollers and track handle the added weight.  I live in New Mexico and we have severe winds, at times 60+mph and I like the idea of these tracks which capture the roller. I think they will keep the roof out of the neighbors yard.


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#2 TimK

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Posted 23 June 2022 - 09:16 AM

I would think the new roof design is significantly heavier than the original.

Without knowing exact figures or the specific design elements I would guess that the standard garage door track will not be up to the task.

 

When people use reinforced roofs on ROR observatories they seem to use V-rollers and an inverted angle iron to allow the roof to roll.

I've also seen a few with flanged rollers (think railroad) running on a flat plate.

 

If you have a high wind concern and the roof is not excessively heavy you need to consider tie downs for when the roof is closed or a anti lift system that keeps the roof on the roller track.



#3 lee14

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Posted 23 June 2022 - 09:21 AM

I used the garage door track and roller system when I built my 10' x 12' ROR almost thirty years ago. It passed through a 90 mph straight-line wind event without a hitch. The inherent capture feature of the garage door tracks will indeed prevent the roof from lifting up. Matching eyebolts with pegs at at least one corner will prevent horizontal movement. 

 

3/4" thick material for a roof deck is overkill. Here in NY 1/2" plywood is more than sufficient to carry a snow load of several feet. I suspect the 3/4 material they're supplying is OSB, which is decidedly inferior to plywood. If it gets wet, it will swell like a sponge, and there's no returning in to the original condition. It lacks the structural strength of plywood, you can put a hammer right through it. Additionally, it is far more prone to sagging.

 

You're looking at a very heavy roof, so you'll need to use more rollers than would be typical for a garage door installation. They're simply not designed for a heavy horizontal load, but if you space them no more than 18" apart they'll be fine.

 

Lee



#4 lee14

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Posted 23 June 2022 - 09:26 AM

This system has been in use for almost thirty years. Spreading the roof load between enough rollers is key.

 

Lee

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#5 speedster

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Posted 23 June 2022 - 09:15 PM

3" ball bearing steel garage door rollers are good for #150 each.  2" ball bearing steel rollers are good for #35.  Box rail also captures the trolleys and they are good for #225 to #400.  Hanging the roof on trolleys eliminates issues with dirt and ice in the track as the box rail slot is down.



#6 Simply Peter

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Posted 23 June 2022 - 11:46 PM

Lee,

Thanks for letting me know that you have had good luck with the garage door track and rollers. 30 years is pretty amazing, if I am able to use my observatory for thirty years I'll only be 101. Before I decided on purchasing a shed kit I had purchased the track and rollers. I bought heavy duty ball bearing rollers and have enough of them to place them every 12". 

 

The 3/4" roof boards I referred to  are actually spruce boards  and not CDX or plywood.  On a square foot basis I think the roof will be lighter than if I had used 3/4" ply or CDX.  

Peter


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#7 lee14

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Posted 24 June 2022 - 04:55 AM

Lee,

Thanks for letting me know that you have had good luck with the garage door track and rollers. 30 years is pretty amazing, if I am able to use my observatory for thirty years I'll only be 101. Before I decided on purchasing a shed kit I had purchased the track and rollers. I bought heavy duty ball bearing rollers and have enough of them to place them every 12". 

 

The 3/4" roof boards I referred to  are actually spruce boards  and not CDX or plywood.  On a square foot basis I think the roof will be lighter than if I had used 3/4" ply or CDX.  

Peter

Sounds like a good plan. And yes, I'm sure the spruce boards will be lighter. It's the shingles that can add significant weight. I used cedar shakes because they were lighter than asphalt/fiberglas, but they just don't have the same lifetime. If and when I replace the roof, I'd use metal.

 

We're the same age!

 

Lee



#8 gmiller123456

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Posted 28 June 2022 - 08:44 AM

I built mine with a plywood roof and shingles.  The track and rollers held up just fine, the brackets slowly bent over time until after about 10-15 years the end of the roof came to rest on the observatory which stopped further sinking.  More brackets would probably have helped.  It sill worked fine until I moved, only required a good pull to get it started initially.  I will be building another one soon, but plan to stick with the metal roof to prevent that problem.


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#9 lee14

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Posted 28 June 2022 - 09:18 AM

I built mine with a plywood roof and shingles.  The track and rollers held up just fine, the brackets slowly bent over time until after about 10-15 years the end of the roof came to rest on the observatory which stopped further sinking.  More brackets would probably have helped.  It sill worked fine until I moved, only required a good pull to get it started initially.  I will be building another one soon, but plan to stick with the metal roof to prevent that problem.

The track must be screwed or bolted to a a structural piece of framing lumber, including the track section that receives the rolled off roof. This will prevent any tendency to sag.

 

Lee



#10 gmiller123456

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Posted 28 June 2022 - 10:46 PM

The track must be screwed or bolted to a a structural piece of framing lumber, including the track section that receives the rolled off roof. This will prevent any tendency to sag.

 

It was not the track that sagged, it was the brackets that hold the rollers.




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