My Garage is falling down...

[Jetboy]

I have an older shed roof garage with very low angle roof. Typical of a 50's garage. Two car about 22' span. This winter has been a high snow load. Last week the door wouldn't open. It was hitting one of the roof joists. Are they called joists? Basically 2x12s that make up the roof structure. They span the full 22 feet.

Upon inspection two of them have failed and split. and two more are sagging. s***!

So I put a couple 2x4s together to make a temporary internal wall to support the failing area.

I don't see a great way to replace them. I'm not even sure where to buy a 24 foot 2x12. I assume a lumber yard could get them?

I'm also not entirely sure how I'd go about getting them into place It would seem like I'd need to lift the roof a bit then work them in. I don't see any easy solution.

 

[PAToyota]

Well, the easy solution is to "sister" the failing members. Jack things back into place and lay another 2x12 roof joist into place alongside the failure and nail, screw, or bolt them together.

In some cases you can even get away with a shorter piece to just bridge the failure. In your case, though, the "sister" will add more weight to an already overloaded member unless you span from the walls.

Depending on how the roof is constructed, it may be possible to open up the fascia of the roof on the one side so that you can slide new members in alongside the old members and use an LVL or iJoist.

 

[Jetboy]

Thanks. I had considered the possibility of using two 16' or so joists to pancake the old one that way I'd have a good overlap in the middle and not need to open up a side to get them in place.

 

[cody c]

Thanks. I had considered the possibility of using two 16' or so joists to pancake the old one that way I'd have a good overlap in the middle and not need to open up a side to get them in place.

As per above, try and find some "banana's" with a good crown to them to get a bit of a peak instead of a sag, and get a couple big tubes of PL 500, glue and screw the sister joists on, while raising the center of the original joists just past straight with a couple floor jacks, and leave them for a day or three for the glue to cure fully.

Id even suggest adding two boards to each existing joist where there is some sag.

Maybe shoveling that roof off carefully first wouldnt be a bad idea.

 

[lowenbrau]

If you are going to replace those 2x12s, I-joists are probably going to do the job better and be easier to source in that length. 12" I joists are available up to 80 feet long.

 

[KLF]

Like posted above, an engineered LVL is stronger than solid 2x12, plus a 24' long 2x12 is gonna be crazy expensive. But, the problem with LVLs is bracing them for shear at the ends. You can't really make a birds-mouth cut, it will ruin the strength.

The better more permanent solution would be to pull the roof off and drop on some trusses. My garage is 24' wide, and the bottom stringers on my rafters are only 2x6's clear span (no idea where they got 24' long 2x6's), the rafters are 2x10s on 8/12 pitch. The stringers were really drooping when we first moved in, I measured 4-6" of droop with a laser level. I made a jacking post to lift them back up to level, and went up and added some 2x4 bracing with 1/2" plywood gusset plates, effectively building a truss in place. Much more stable now, no bounce when I'm up there in the storage space.

 

[bkfj40]

typically, they are called roof rafters and floor joists....

One option to consider is light gage metal framing. If you use TJI, you won't be able to sister them to the existing unless you block out the web. LVLs are gonna be expensive.

One other option is to place a new beam underneath the existing rafters running perpendicular to the rafters....this would only work if you have single wide garage doors....

you didn't mention where you live - what is your building code snow load requirements?

 

[Jetboy]

I'm in Utah. I'm sure it's not up to any sort of code. This garage was built back in the 50's. I'm going to have an engineer come take a look and make the call on whether we need to pull the whole roof or whether reinforcing the existing structure is a viable option. (I have to have an engineer approve for my insurance policy.)

There's a reasonable chance I'll just raze the building and start over with a more modern structure. Since the existing walls are framed for a shed roof with a 1/12 slope, if it comes down to putting trusses on, I'll probably just knock down the whole thing. I'm not sure it's viable to build some sort of framed wedges to level the original pitch to put trusses on.