Joists -- Hang Them or let them ride?

[aayjaber]

When joists run over beams; what is the difference in letting them ride on the beam or just hang them with joist hangers. What is the difference structurally and cost? I am not sure how expensive joist hangers are?

 

[apsix]

Structurally, nailing the joists to a nailer bolted to the top of the beam has got to be better. It's also quicker and therefore cheaper.
Hangers are used when the space is not available and the beam is required to be in the same plane as the joists.

 

[jike]

It is usually not a matter of the cost of the structural elements by themselves that is important. Other things such as ducts and lights and how they are integreted in the total space with the structure will ultimately affect the total cost. The total cost of the building is the bottom line, not the cost of the individual systems alone since minimizing one may raise the cost of another.

If possible, joists fastened to a nailer bolted to the top flange of the beam is prefered, if it works with the total building.

 

[vandede427]

if you hang them, make sure your joist hanger has rotational restraint.

if you lap them over the beam, make sure you provide blocking to prevent rotation.

 

[BAretired]

Are the beams wood or steel? Are the joists dimension lumber or TJIs?

If hanging dimension lumber joists from steel beams, be sure to set top of joist higher than top of steel to allow for shrinkage of the joist. Otherwise, you will see a hump in the floor or roof after shrinkage has taken place.

BA

 

[msquared48]

Whether the joists are hung or not is also affectecd by these two things not mentrioned yet:

1. The overall allowable building height, and

2. Mechanical chase issues.

Mike McCann
MMC Engineering