Since my observatory run-off roof hasn’t really changed since it was built in 2002, it needs some remedial work. That’s a hell of a lot of weight sliding around to risk any issues with it! The roof isn’t too hard to roll off although clearly there are some issues of alignment and friction to deal with.
My first task was to ensure the rails that the roof rolls off onto are level and secure. I ran a line between the front edge of the shed to the back of the rail, ensuring that the line made contact with the back edge of the shed, which provides a line that the rails should contact. While the rail closest to the house was bang on, the rail nearest the fence was quite low due to the soil moving around, likely due to the construction of my neighbor’s rather sizable fence. I braced the rail with a board to lift the posts out of their cottage blocks, and raised the NE cottage block several inches. Perfectly level now! The N side of the rails are slightly raised to ensure the roof tends to run BACK onto the shed worst case rather than off the rails!
My next task is to replace the current rollers on the shed (see below) with a v-groove wheel on a angle iron rail.
I’ll be replacing the three existing rollers per side with five of the new rollers per side, which should make the roof roll off much more easily. The rollers were obtained from Amazon (where else?) at $20CDN a pair. They are each 660lbs capacity, similar to the existing rollers but beefier mounts give me a higher level of confidence that the wheels will resist lateral loads. Some 8′ lengths of 3/4 x 3/4 x 1/8 in. steel were obtained from Princess Auto for $9.99 each times five. One of the lengths is split into 2 4′ lengths and all will be welded together to create two 20′ rails.
My intent is also to raise the roof about 1/2″ to ensure it clears both the N side of the shed (it rubs currently) as well as allowing a better fit for the front gable, which needs me to lift the front end of the roof a bit to fit in. Given that the current rollers are 2 3/4″ above the side of the shed, and the new rollers are only 2 5/8″ tall I’ll be adding a 3/4″ spacer to the top of the roller to get the height I need.
Once the roof is mounted on the new roller system I’ll feel more comfortable adding some weight to it with some panelling to improve the look and protect my head from the rafters and roofing nails! This change will also enable automation of the roof with a winch I’ve had in a box for 12 years 🙂
Next I need to figure out a way to lift the roof enough to remove the existing rollers and add the new rail and rollers without the roof ending up in the garden! Stay tuned!