What is this metal cable spanning my garage ceiling?

March 15, 2020 9:54 PM

Our newly purchased house has a detached garage. A section of the garage has been finished off as a bonus room. The previous owners made some... interesting choices with their DIY work, including leaving this metal cable exposed, spanning the length of the room.

Here’s a couple of photos of the thing. It seems to be a cable, as opposed to a solid rod. It attaches to those metal end points on either side. The garage does not have any automatic doors, just regular doors that swing open on the other side of the structure.

So, what is this thing? We’d like to get rid of it, as we’re finishing off the space to make it usable, and its pretty ugly. Thoughts?

posted by bluloo to Home & Garden (12 answers total)

From the photo, it seems really quite damaged at the point above and to the left of the door? Like, necked-down and ready to snap -- is that correct? Or is it a glob of white paint? If it's the former, you are probably in trouble and should check with a structural engineer because if this thing is NOT important then it should not be stressed like that.

Also, the mounting point seems unusually sturdy; I'm a bit concerned this thing is serving a structural function (as a "tie rod" holding the two opposing walls together). Were it me, I'd cut away the drywall on both sides and get a better look to see how this thing is mounted into the wall structure itself. If it's just a curtain rod type of thingie then it won't be mounted in any serious way; if it's not, then it'll be mounted in a pretty serious way (4x screws minimum per side, and not drywall screws but something more serious like an SDS screw).
posted by aramaic at 10:05 PM on March 15, 2020 [2 favorites]

Response by poster: That is paint. It seems structurally sound throughout.
posted by bluloo at 10:15 PM on March 15, 2020

Looks like a cable rafter tie to me. Is it approximately half way down the building? Does the building have a gable roof? Both would support this being a cable tie. If it is a cable tie you can't remove it or your building will fall down (eventually).
posted by Mitheral at 10:25 PM on March 15, 2020 [6 favorites]

Yes, this looks structural to me. Better call in a structural engineer to be sure.
posted by summerstorm at 10:38 PM on March 15, 2020 [2 favorites]

Looks structural to me, too. It looks like it's under tension, which means that it's keeping the walls from sagging outward and collapsing, much like tie rods in old churches.
posted by brianogilvie at 1:48 AM on March 16, 2020 [1 favorite]

You could build a box around it & pretend that it's a rafter, but that would probably make it look more obvious not less.

Try painting it the same colour as the ceiling. Could blend in fairly well.
posted by rd45 at 2:00 AM on March 16, 2020

Is that a 'cable'? It looks like a threaded rod to my eyes. And the mount point looks like it's structural. Is it solid? It doesn't look like it sags, it looks straight and solid and taught. It looks like a rod. It looks like it's holding the walls together to support the roof. String some christmas lights along it and/or paint it and leave it alone. Probably holding things together.
posted by zengargoyle at 3:33 AM on March 16, 2020 [2 favorites]

Best answer: I am an engineer, I am not your engineer licensed to practise in your area: it's a tie rod or cable. It's in tension to keep the walls together. It's a structural part of the garage: lose it and the walls blow out. Painting it might mask corrosion or damage which you might want to be aware of: its lack of paint hints that it's something that shouldn't be painted for safety.

Make friends with it — it's staying.
posted by scruss at 4:07 AM on March 16, 2020 [18 favorites]

I am also an engineer and also not your engineer. I agree with scruss. Furthermore, my parents' garage has one of those as well; the tops of the side walls were leaning out. The cable has been there for my entire living memory and I'm 45.

You may be able to replace it with either a guided cable or some other structure above the drywall. However, to do that you would 1) need access to the top caps and joist space or cut into the drywall, and 2)proper structureal engineering support.

It absolutely cannot go away, but it can be worked around. Using cables and concrete anchors, I've straightened freestanding garages where every corner was leaning a different direction and all the bottom stud plates were as soft as cake. It's doable.
posted by notsnot at 5:12 AM on March 16, 2020 [3 favorites]

I agree it was put there for a reason, but the reason is not clear. Why only one tie and only towards one end of the building? The ends of the long walls can't blow out because they are tied by the cross wall where the door is. You would expect one or two ties more towards the center of the long walls, not towards one end. The rafters have collar ties that are high up at the flat part of the ceiling, but they may be too high to prevent the rafters from bowing out.

It does seem peculiar unless there is some big external weight on the roof above that tie, like an air conditioner or water tank.
posted by JackFlash at 3:06 PM on March 16, 2020

Or snow.
posted by fshgrl at 6:25 PM on March 16, 2020

That cross-wall might be a later addition (the "bonus room"), and may not be structural. Maybe they cut the other cable that might've been nearer the other end of the building. Who knows if all the permits and engineering has been done correctly to make this garage habitable?
posted by scruss at 1:06 PM on March 17, 2020