Warping/twisting 4" x 4" support post on ROR roof support frame

[fondofchips]

A 4" x 4" support post has warped on the extension support part of the ROR obsy runners. Breaking off the screws that held the original cross beam support on to the support posts.  I've been really lucky here as if the support had failed at night the obsy roof would have fallen off at the outer end.  Top view below.

View from the side, this is after I've done a temporary repair.

Still needs more work, I've done the best temporary fix I can for now.  Shed builder has suggested cutting the post in two but I want to dig down around the concrete and try and twist it back into place if possible.

Good side of the support frame that has not warped shown below.  You can just see a chain here that goes across to the other side and prevents the runners from spreading further apart.  I used 2 x 6mm marine stainless steel eye bolts to hold the chain that picked on existing runner fixings.  They were long enough to hold rubber stops as well they keep the obsy roof further back, it still clears the viewing room walls OK.

I just wanted to show it here to remind other obsy owners to keep an eye on their obsy's ROR roof support extended frames.

The framework now has threaded rod through it, not just wood screws.

Cheers,

Fondofchips.

[Tinker1947]

Is the twisted post a green post, that's not kiln dried or treated....a treated post should stay straight or very close to straight.....

[fondofchips]

Looks like a long normal fence post to me, so that explains the problem.  I'm looking into a more permanent solution that holds the runners OK but allows some movement.

Cheers,

Fondofchips.

[Tinker1947]

I used treated 4" X 4" posts there in the ground around 3' deep held in place with pea shingle, this does allow a little movement but should they need to come out a industrial hoover will suck the shingle out and leave the post free to be removed or adjusted.....my 2 ROF Runners aren't connected.....

a bit extreme but this is just held in the ground by pea shingle.....

[Scorpius]

A 4" x 4" support post has warped on the extension support part of the ROR obsy runners. Breaking off the screws that held the original cross beam support on to the support posts.  I've been really lucky here as if the support had failed at night the obsy roof would have fallen off at the outer end.  Top view below.

View from the side, this is after I've done a temporary repair.

Still needs more work, I've done the best temporary fix I can for now.  Shed builder has suggested cutting the post in two but I want to dig down around the concrete and try and twist it back into place if possible.

Good side of the support frame that has not warped shown below.  You can just see a chain here that goes across to the other side and prevents the runners from spreading further apart.  I used 2 x 6mm marine stainless steel eye bolts to hold the chain that picked on existing runner fixings.  They were long enough to hold rubber stops as well they keep the obsy roof further back, it still clears the viewing room walls OK.

I just wanted to show it here to remind other obsy owners to keep an eye on their obsy's ROR roof support extended frames.

The framework now has threaded rod through it, not just wood screws.

Cheers,

Fondofchips.

Greetings fondofchips,

Sorry to see you’re having issues with your ROR support structure. Looks like the lumber available in the UK is about the same as in the US and I agree with Tinker it was probably green when installed and dried unevenly thereby creating this twisting problem. One way to prevent this is to install temporary or permanent cross-bracing during construction but that alone won’t help once the twisting has occurred.

No reflection on the shed builder but I see one major problem with the way the posts were installed. You should never rely solely on surface to surface contact held together by screws as a structural support assembly. Horizontal framing should always rest directly on top of a post or beam since the average wood screw has no real resistance to vertical shear forces. The minimum bearing per US codes for wood framing is 1.5” unless engineered framing connectors such as joist hangers, etc. are used.

However, you may be able to make some retro-fits to prevent similar failures elsewhere and possibly even “draw” the renegade post back into place by trying the following. I would drill all the way through the horizontal beams and through the vertical post then install bolts to try & slowly twist the post back into its original position. The bolts would need to be fairly substantial (at least a ½” dia.) and be sure to use large washers or a steel plate on both sides to prevent just sinking the bolt heads and nuts into the wood. A large, heavy duty C-clamp would help the bolts along and you’d need to gradually tighten them over several days to slowly draw the post back into place. Then once you get it back in line, install 2x4's vertically alongside the support post so the horizontal ones are actually resting on wood. Ideally the 2x4's would extend all the way to the post’s concrete footing but if that’s not practical, they should be as long as possible and connected to the post with heavy-duty screws or better yet, through bolts with exterior grade construction adhesive between the mating surfaces. It would probably be prudent to do this for each post - even if they aren’t showing any separation right now - as a precaution against future problems. It would also be advisable to do everything you can to lock the horizontal beams in place by temporarily cross-bracing them to the other side and/or to the ground so you actually bring the vertical post back into alignment rather than pulling the horizontal ones out of alignment.

It's possible I'm misinterpreting the photos and there may be other ways to address the issue but the key is not to rely strictly on standard screws to support a vertical load since they are not designed to resist vertical shear.

Good luck and clear skies,

Scorpius

[fondofchips]

Scorpius - you are spot on, another picture of the good side.  The original 4" x 2" cross beam has been cut in two and screwed to the outside of both posts to support the runners directly underneath.

The metal runners are set high on the support timbers so the chain stops them from spreading apart.

I'm still working on a permanent solution, need to sort out the design, the roof is working OK for now and is running well.  Might go for some decent metal support brackets.

Thanks to all of you for your suggestions.

Cheers,

Fondofchips.