Ceiling Joist and Joist Hangers

[woodman1967]

Hello All,

Been working on a few projects (two story manufactured housing in Canada). Due to the way the homes are put together onsite the main floor modules have 2"x6" ceiling joists. These joists only support the gypsum ceiling. The joists are fastened to a sill beam and rest on the top of the 2"x6" exterior wall. The setup allows for a max of 1/2" of bearing for the joists. The specs call for these ceiling joists to hung on joist hangers. Considering these joists are only carrying dead load are the hangers necessary or would nails provide the bearing required? I tried to add a drawing but nothing happens when I click on the link.

 

[woodman1967]

Here is the section, I tried a different browser and had no issue. Must have had a pop-up blocker turned on in my original browser.

 

[jayrod12]

Although I can get on board with the argument that maybe it's not required, if the drawings say it should be there, and this is a new build, I'd be putting them in.

If it were an existing condition that we uncovered, I could probably be persuaded to let it go. Funny how circumstances change things.

 

[lexpatrie]

Here's the image if anyone is interested.

 

[woodman1967]

Just to clarify any confusion about the drawing requirements. The drawing does say "No hangers". But in this case it isn't a spec from the designer but a request to verify if it is necessary. They had been using hangers for years but have no specifications that stated that in writing.

 

[lexpatrie]

I'm not a huge fan of relying on shear loads in a nail that's into the end grain of a joist, further, the capacity isn't fantastic, compared to a joist hanger which can at least partly function in bearing of the joist on the seat, and the top flange bearing on the rim board.

Also worth noting is the eccentricity of the load relative to the top plate, as drawn, and it's pretty likely the plate will crush with so little bearing and the end nail approach with the limited stiffness.

 

[woodman1967]

Thanks lexpatrie, that makes sense. We were thinking the only load carried by the ceiling joists was the ceiling dead load. But you are correct that there would be second floor loads transferred to the ceiling joists through the 2"x6" sill plate. We will continue to use the hangers.

Thanks everyone