Sheathing

Question: 

Is it possible to construct an assembly for ceiling between first and second floors using 2x with few layers of gypsum to obtain a 3-hour fire rating?

Question: 

I have been hired by an insurance company to determine the extent of damage to roof trusses exposed to fire. How much fire damage compromises the structural integrity of the truss?

Question: 

I am looking for a 1-hour roof/ceiling assembly for wood truss construction. I would like to apply the drywall directly to the bottom of the truss and also have insulation for sound control. Is this possible without using channels and what UL number would I use?

Question: 

It is critical that permanent top chord bracing is supplied by proper nailing of the valley truss bottom chords to the carrying truss top chords, through purlins or properly installed rated roof sheathing. If the sheathing is not carried through under the valley framing, then the permanent top chord bracing must be supplied in another manner.

This presentation provides information on overdriven nails in structural sheathing.

All building codes provide provisions for the attachment of structural sheathing to wall and roof framing members. In almost every case, the published capacity of the sheathing and fasteners assume the head of the fastener is flush with the surface of the sheathing. This Research Report discusses guidance when fasteners are overdriven.

This presentation provides information on and requirements for truss repairs.

Gypsum wallboard provides an excellent example as to
why accurate design values are so vital to structural design.

Introduction: Why the Interior Finish Installation Is Important

  • Plywood and OSB design values are given; those that are doing repairs in your office should have a good feel for the similarities and differences.
  • Plywood and OSB generally have similar design properties with a key exception of fastener strength where plywood will require more fasteners to be used.
  • If a truss repair specifies only OSB, plywood should not be substituted without written permission from the registered design professional who prepared the truss repair design drawing.
  • The strength axis of a structural panel is the direction parallel to the grain of the wood fiber in the face and back surfaces of the panel.
  • The strength axis is usually the long dimension of the panel.
  • The IBC provides two tables with the allowable spans and loads (psf) for wood structural panel sheathing installed continuous over two or more spans with their strength axis perpendicular and parallel to the supports.