garage - contractor or structural engineer?

[joyb]

Hi All,
I'm getting closer on cleaning up all the trim, and I'm starting to look at other projects. I'm unsure about the safety of our detached garage. It's a two stall, and it looks like it originally was much shorter, and then had a little addition off the back to make it deeper (the addition is the white ceiling/everything past the main beam). The part that looks kind of unsafe to me is that there are metal cables that seem to be holding the walls together. It's kind of hard to see, but the cables seem to be tied around the (I'm guessing load-bearing) beam on each end (tied around a pipe on top of the beam)

garage2.JPG (112.25 KiB) Viewed 744 times

, and then joined together with this screw-type thing to kind of winch it together (where the rope is dangling down)

garage.JPG (98.24 KiB) Viewed 744 times

At least that's how I'm imagining it works. Those blocks of wood wedged between the cable and the beam look especially concerning to me.

I'd like to have someone in to take a look. Would a structural engineer be appropriate or overkill? Would a contractor be able to tell me anything about the safety (or danger) of the structure?

[SkipW]

If the cable was actually attached to the posts at the end of the beam, I would say that someone was trying to approximate the effects of a collar tie to keep the side walls from pushing out when the back wall was removed, but it does not look as though that cable goes around the outside posts (at least from what I can see)

The next possibility I thought was to keep the beam from bowing in the middle, as it looks like the blocking is acting to pull the ends down on the beam/push the middle up, but that seems unlikely as well.

Third thought is that the cables were "designed" to keep the center posts in line with the beam when the back wall came out and the blocking is simply to keep the cables far enough down on the posts to capture them. But I'm not sure why a few gussets and plates could not accomplish the same thing.

So, bottom line is....Haven't a clue ;-} But a contractor could certainly review the setup in person (hard to do from pics) and let you know what remedy is required and assure you of the safety, or not, of the structure. In my opinion a SE would be an expense not needed.

[Gothichome]

I agree with Skip, this set up makes no sense. The turn buckles are all the way out, so there's lots of room for tensioning. I highly dought the cables would hold that centre post in place on the beam, as Skip mentioned a couple of good tie plates would do that. As far as the blocking, if there is a notch that the pipe sits in, the blocks would provide some vertical loading to keep the pipe in the notch.
In the end it would seem all the cable is doing is holding the beam in compression, by chance is the beam made of two sections with a joint, maybe the joint had failed.

[Gothichome]

Joyb, just had another look at your pics, can you confirm that one end of that cable is indeed wrapped around a post, when I blew the pick up it looks like it may be (the end without the broom). If so, maybe Skips first thought is correct. And the cable might just be pulling that one post in place.

[Casey]

I suspect it was intended to function as a truss rod, which is why it runs from a high spot at the ends, and has the blocking in the middle. If made tight as can be, it supplies uplift at the blocks, as the cable tries to become a straight line, it lifts the pillow blocks.
Casey

[Gothichome]

Yes, but the positioning of the blocks in relation to the post, in my mind, I see a simple wedging of the beam at the post as a much simpler solution over that cable set up.

[joyb]

Thank you for all of the replies and ideas! I'm looking up terms, and it is interesting trying to get a sense of the function and their purpose.

This would be the far end (not yet pictured really)

other end.JPG (67.36 KiB) Viewed 698 times

This would be the center and then looking at the broom end

center.JPG (126.13 KiB) Viewed 698 times

length.JPG (108.55 KiB) Viewed 698 times

The garage needs new garage doors and a functional entry door, and there's an attic space that would be great to use if we can actually get up there. It's reassuring, too, that a contractor should be able to give us ideas about what we can do or should do to get the space more functional.

[joyb]

In rereading I just realized I forgot to look to see if there were two pieces. There are the two (sistered?) beams, but I don't recall a joint. I'll go out an look tomorrow!

[Gothichome]

Johb, by chance is your garage the old carriage shed? The space above may have been the hay loft. That beam probably had several posts between the main post and the wall to transfer the load. They have since been removed when the extension was added to open up some space. Still, with what remains this current set up in my mind will not take the load that the missing posts did. There would need to be additional blocking between what is there and the outer wall. I also noticed all the joists on the older section have a bit of a bow and have been sisters. Some thing heavy had been stored up there for many years.
Oh, sorry I did not answer your question directly, a competent contractor should be able to deal with this.

[raine]

http://cr4.globalspec.com/thread/66957/ ... on-25-Tube
scroll down to # 10 . although they are not talking about wood beams I think the idea could be the same.
I would quess that the cables were put there to carry load so they didnt have to put in more posts because that would block the parking area.