Nailing Pattern

[jopalu]

Can you direct me to a Nailing Pattern for SIDE-LOADED multi-ply wood (dimension lumber) beams?

Thank you...

 

[UcfSE]

Have you tried calculating the nailing required using the shear flow equation?

 

[jopalu]

UcfSE,

I'm not familiar with the shear flow equation ...

 

[akastud]

jopalu,

Unit Shear = VQ/I. See any Materials Text

this will give you a force in pounds per inch length of your beam then you can use your nail capacity to calculate nail spacing.

 

[DaveAtkins]

I don't think the shear flow equation applies here (I am assuming all the plies are oriented vertically). All you need to do is make sure you have enough nails between the loaded ply and the adjacent plies to transfer whatever percentage of the load must be carried by all the adjacent plies.

DaveAtkins

 

[woodengineer]

Dave is correct. This is the same technique for attaching multy ply-girder trusses.

Jordan

 

[UcfSE]

Dave, I understood jopalu to mean by the term "side-loaded" that the beam is loaded on its side, with the line of force perpendicular to the plies. If that is the case, he would need to calculate the nailing he needs for a minimum. jopalu, is that what you mean?

The shear flow equation maybe be found in just about any decent mechanics of materials book.

 

[jopalu]

UcfSE,

Yes. Side-loaded - bearing only on one ply which is to be fastened to the others.

 

[CJJS]

Typically, in wood design, SIDE LOADED means, as Dave indicated, that the members are oriented vertically, and that there are joists or other structural members framing into one or both of the vertical faces. In which case, you will need enough nails to transfer the forces to the other members.

 

[MotorCity]

My experience with specifying nail patterns is that it is generally an academic exercise, but maybe the practice is different in other areas. I've found that even if you specify a nail pattern it is rarely followed, even by reputable contractors. Many timber framers seem to laugh when they see that the engineer has told them how many nails to use and where to put them. I still specify nail patterns from time to time but more to cover myself. Can anyone else relate to this?

 

[woodengineer]

MotorCity,

It is important to call out nail patterns. Your point is well taken regarding contractors not following your specification. Most recently I informed a contractor that my plans were not suggestive, but rather a directive. Since we all know builders are using pneumatic nails, it is not enough just to designate a penny weight of nail and spacing. I don't even say 8d common, box, sinker, etc anymore. I specify nails by diameter and length (0.131" x 3") that way they can use pneumatic nail, and are more likely to choose the right size.

Jordan

 

[oldrunner]

Bascially this configuration becomes a laminated beam, so it isn't just the nailing pattern that must be determined but also the adequacy of the plywood with each pieces' individual plys and the fact that there is a 90 degree orientation within each plywood sheet. Can be done, but tedious.