Sheathing

Valley Sets

Question: 

What are the requirements for installing valley sets over roof trusses? I am interested in nailing and support conditions. Some engineers ask for the bottom chord of the valley truss to be ripped to match the roof pitch of the underlying trusses. Is this necessary? How can I calculate values for uplift resistance for the building inspector?

Post Fire Retardant Treatment

Question: 

Is a Class A fire rating (provided by our liquid spray-on fire retardant) acceptable in certain situations?

Two Hour Assembly Ul Number

Question: 

We have a local builder wishing to use floor trusses with a 2-hour assembly. I have shown him the 2-hour design on pages 17-27 of the second edition of SBCA’s Metal Plate Connected Wood Truss Handbook. Is this assembly UL approved? If so, what is the design number?

Fire Damage Assessment

Question: 

How do you evaluate whether a metal plate connected truss is still usable after exposure to fire? Are there any recommended tests?

Overdriven Nails in Structural Sheathings - Educational Program

This presentation provides information on overdriven nails in structural sheathing.

Overdriven Nails in Structural Sheathings

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.

Truss Repair - Educational Program

This presentation provides information on and requirements for truss repairs.

Installation of Interior Gypsum Board Finish

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 vs. OSB Truss Repairs

  • 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.

Strength Axis in Wood Structural Panels

  • 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.