Truss Strength

[jrepp44]

Typical prefabricated roof trusses (2 x 6). Spacing is 29" on center in the shop area. If I temporarily place 3/4" plywood on top of the bottom chord would it be safe to walk on?

 

[Deere Dude]

I stand on my 2x4 trusses all the time in the house, and on my brothers pole shed 2x4 trusses 24" on center and 30 foot long. I never heard of 29" on center. That is odd.

Those are spaced close enough to where walking won't be a problem unless you are really a beefer. You will like the shed.

 

[bcp]

I would do it.

Fasten a couple of 2x4's to the plywood bottom, about 2 inches or 32 inches apart. When you are standing on it and exerting force, you don't want the plywood to slide off.

Bruce

 

[/pine]

For just "walking around"...running wires etc it will be fine...but unless specified when the trusses were built...the bottom chords are not designed to carry any live loads...over time, even a minor load on a single unfortified truss member will cause it to sag...

 

[EddieWalker]

Yes, it will be fine,but for the effort involved in getting plywood up there, I would just use long 2x6's.

 

[bigtiller]

A 2x6 is what my 54x75 building has, right down the center of the building. My trusses are 7.5 feet on center.

 

[LD1]

Yes, it will be fine,but for the effort involved in getting plywood up there, I would just use long 2x6's.

Agreed.

 

[/pine]

I'm surprised the truss engineering doesn't specify at least a "rat run" along the bottom chords...

 

[hddnis]

For just "walking around"...running wires etc it will be fine...but unless specified when the trusses were built...the bottom chords are not designed to carry any live loads...over time, even a minor load on a single unfortified truss member will cause it to sag...

That must be why so many trusses specify that they don't reach rated load capacity unless you hang thousands of pounds of drywall from the bottom of them.

 

[Raspy]

Of course that truss is strong enough to hold the weight of a person.

If there was a failure it would be because the bottom chord was not connected to the diagonals strong enough. I've seen those little plates they press on to hold it all together, come off. I agree with Eddie that long 2X6s would be better. That 29" thing is interesting.