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Discussion Starter · #1 ·
My garage is 19' by 25', stick build. It is unfinished all around, without drywall or attic. The rafters going to the peak are 2 x 6, 24" on center. Then the joists/rafter ties going across the 19' span, parallel with the ground are 2 x 6, spaced 48" on center (connected @ every other rafter). There is a 2 x 4 running the 25', spliced that sits on top of the joists/rafter ties. the joists/rafter ties appear to be serving as spreaders as opposed to structural support.

My roof is asphalt shingle (over wood shingle in some places unfortunately), and we're in San Diego (no snow). 1962 build.

I have been using the 48" spaced joists for storage, with 2 bikes hung, ski's, some lighter lumber, car cargo rack, and 2 large 4 x 8 particle board slats towards the middle with tubs of ligther stuff (decorations, etc). Also have garage door. Given the 48" spacing, the particle board is bowing in.

After research, it looks like I should not have anything stored on the rafters. Can anyone confirm? Should I have a contractor look at it for reinforcement - even without using for storage? Looks like the 19' span on 2 x 6's may not be safe even if not bearing weight (based on current code)? Would love some advice!!
 

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retired framer
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Yes they are there to hold the two outside walls from spreading and there by holding the roof in place.

19 or 25 ft would be over span for almost anything you could use for joists so adding any more weight up there should be after a discussion with an engineer.
 

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Master General ReEngineer
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After research, it looks like I should not have anything stored on the rafters. Can anyone confirm?
Ayuh,.... That is correct,....

I doubt they'll carry much more than the dust that settles on 'em,...
That's a very minimalistly built garage,....
 

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People do this all the time, even though they're technically not engineered for that purpose.

Certainly there is some weight-carrying capacity there. In theory their purpose is to be in tension, keeping the walls from pulling apart. Weight on top doesn't affect this much, up to a point.

Of course, that's the rub. What's that point? If you see, or even suspect, any deflection with the load you have, then you could always run supports up to the rafters, sort of like what you'd see in an engineered truss.

I am not a civil engineer. I don't even own a striped hat. I'm just passing along what I've seen.
 

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Discussion Starter · #5 ·
CaptTom - even with a 20' span on a 2 x 6?

This is comforting, but I did hold a level up to them and there appears to be some deflection towards the center (sag).
 

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There undersized, over spanned, and over spaced for any top loading.
 
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