davethompson413 t1_jedq492 wrote on March 31, 2023 at 7:33 AM

Reply to comment by me-chewbacca in Need to hang something from ceiling and unsure what lumber to use by me-chewbacca

It would be the same, in that a 2x4 bottom chord of an engineered truss is not designed to carry any live load other than the roof load. A person hanging from a 2x4 risks breaking the 2x4, because by themselves, 2x4s are not structural.

Doctor_Frasier_Crane t1_jee6t7c wrote on March 31, 2023 at 11:21 AM

I think he’s safe if he spreads the load across several joist. Plenty of people (me included) have many hundreds of pounds hanging from the garage trusses.

The risk is likely not breaking, but rather slight movement that can cause cracks in the drywall.

davethompson413 t1_jef6uof wrote on March 31, 2023 at 3:55 PM

They're not joists. Joists are structural, 2x4s are not. It really is that simple. When running horizontally, there is no span chart for a 2x4.

Doctor_Frasier_Crane t1_jefd3ox wrote on March 31, 2023 at 4:35 PM

Technically, that’s correct, they’re part of the truss assembly. The bottom chord.

A quick Google search does find plenty of results for span tables that includes 2x4’s though.

davethompson413 t1_jefj786 wrote on March 31, 2023 at 5:15 PM

Span charts for 10 pounds per square foot. Not really walkable. And at 30 psf, the 2x4s disappear from the chart.