Design

Roof Truss Nailing With Hurricane Clips

Question: 

If you use hurricane clips to secure roof trusses from uplift, are you allowed to use fewer than the typical three nails in the bearing heel of the roof truss? I am concerned because we want to do the right fastening schedule, but three nails in addition to the hurricane clip splits the wood. What is the standard recommendation?

Bracketless Connections

Question: 

Are there any trusses that are supported strictly by the wood itself without any mechanical connections such as brackets?

Finger Jointed Material

Question: 

Is finger-jointed material allowed in the manufacturing of trusses?

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?

Drilled Hole In Truss

Question: 

I need to know how to repair a hole that has been drilled through a truss. In installing the wiring we improperly put the wires through the truss and now need to know the proper way to repair it.

Gable End Bracing

Question: 

Some building designers believe that gable end webs need to be L-braced to 90% of the web length, which sounds fine. However, they spec that scissors gable end webs need to be braced to 100% of the web length. That means that in the field they are notching the braces to fit around top and bottom chords – you can imagine how difficult that can be. Is that necessary or even the intent of the web L-bracing?

Steel Vs Wood Truss Bracing

Question: 

As a forensic engineer who has investigated numerous collapses of wood truss systems, I find your web site an excellent resource on the proper erection of wood trusses. What are your opinions on steel trusses, particularly with regards to installation and bracing? Do you feel that the installation and bracing techniques utilized for wood trusses are applicable to steel trusses? Do you know if that is the general industry standard or are there specific requirements and guidelines for steel trusses? Is there a particular guideline/commentary available for metal trusses?

Truss Failure And Repair

Question: 

I am a professional engineer looking for information concerning the failure of metal plate connected wood trusses and methods of repair. I am looking for this information with regard to developing recommendations for the repair of truss systems in the floor structures of two-story multi-family dwellings. I see frequent failure of truss systems of this type in both in bending and due to catastrophic failure at the gussets.

Turb O Webs

Question: 

We have been using Turb-O-Webs for about four months. We are very happy with their performance, although there have been a few ripples along the way. The main thing that concerns me at present is the need for performance documentation and testing data. Do you have anything that will help, or know of people or organizations that could offer assistance?

One Hour Fire Rated Assemblies

Question: 

The Gypsum Association “Fire Resistance Design Manual” (GA-600-12) lists file RC2601 with two layers of 5/8 in. gypsum wallboard (GWB) on wood joists.