Joist bearing

[Sifu]

Joists and rafters are required to bear on 11/2" on wood or metal, not less than 3" on masonry. How is this accomplished with valley's?

R802.6 Bearing. The ends of each rafter or ceiling joist shall have

not less than 11/ 2 inches (38 mm) of bearing on wood or metal and

not less than 3 inches (76 mm) on masonry or concrete.

 

[KZQuixote]

Not with my code books right now but there's a prescriptive nailing requirement for ridges, valleys and jacks. No bearing required.

Bill

 

[GBrackins]

section 802.3 Framing details provides the description for a valley connection. As Bill says there is a prescriptive requirement for the number and size of nails making the connection.

 

[Sifu]

So the more specific over-rides 802.6? The reason I ask is I have a guy using "pressure blocks" to connect ceiling joists and in some cases rafters. I do not permit this based on 802.6 but the argument is the valley rafter connection without bearing.

 

[steveray]

Hip and valley rafters shall be supported at the ridge by a brace to a bearing partition or be designed to carry and distribute the specific load at that point.

802.3.....I think.....

 

[Sifu]

Got the support stuff (extremely weak as it is) just looking for the connection. I agree with the assertions by KZ and GB, more specific provisions apply.

 

[KZQuixote]

We just had a good discussion about power blocking Here: http://www.inspectpa.com/forum/showthread.php?7960-Floor-joist-toenailed-to-girder-beam

DRP even did a shear calc.

Bill

 

[Sifu]

Read both previous threads. I had read them in the past when this builder used these blocks before. I came to the same conclusion then as I do now. I like the "power/pressure blocks" for the finish aspects and the advantages over what I am not a fan of.....ledger/notches. I don't like them because they are not in the code and at the end of the day the code saves me if a problem occurs. In this case the builder has several locations with this blocking. 1) a floor, which to me is a little more critical, 2) a short ceiling span, which is less critical and 3) a long ceiling span which is a little more critical but where the blocks are very loose, providing no positive connection to the joists and you can see the nails. I usually would permit the short span non-critical stuff but now I feel I need to turn down the poorly built stuff. I guess I feel a little funny saying you can do whats not in the code if you do it well.......then again I do that every day with rafter ties!

 

[GBrackins]

So the more specific over-rides 802.6? The reason I ask is I have a guy using "pressure blocks" to connect ceiling joists and in some cases rafters. I do not permit this based on 802.6 but the argument is the valley rafter connection without bearing.

the plumb cut on the rafter ends are bearing upon the ridge at one end and the valley on the other. that's why the ridge and valley have to be at minimum the same depth as the plumb cut.

 

[Big Mac]

Framing anchors are always an option

 

[DRP]

The valley jack rafters bear against the ridge but hang on the valley.

With any connection determine the load, know the strength of the connectors and make the appropriate connections. The prescriptive connections for those joints really should be better or not in the codebook.

Do you allow the contractor to choose which simpson hanger to use? I can hang a joist with any of several with different capacities. If I nail a non simpson steel plate over a joint do you fail it because it doesn't have a stamp? I can give you the data from the NDS easily. Do you fail a nailed connection without a stamp, again the data is readily available. ALL three cases are identical, someone is "engineering" a connection. Simpson has simply done a very good job of marketing their data. A nail has data, we know how much load a nail is allowed to carry, a piece of sheet metal has data...

That said I use simpson hangers not pressure blocks and on all but the shortest jacks I'll use an adjustable plate over the joint. But I can do it either way and sure see both sides of this.