Construction

Responsibility For Multi Ply Girder Truss Assembly

Question: 

I am reviewing a truss package that includes multi-ply trusses. Where do I find the requirements for the attachment of the individual trusses to each other (nails and/or bolts)? Is this a requirement that the structural engineer of record needs to supply or is it the responsibility of the truss manufacturer to design?

Statistics On Truss Repairs

Question: 

How often are trusses repaired?

Cutting Trusses

Question: 

Our home has 2x4 roof trusses spanning 25 ft. spaced 16 in. O.C. Currently, there is limited attic storage on a plywood subfloor on the bottom chords, accessed via a small hatch in a closet. We would like to install a fold-down attic stair with a rough opening size of 25.5 in. x 54 in., with the long dimension perpendicular to the trusses. This would mean cutting the bottom chords of three trusses to frame the opening. Is this possible?

Partition Separation Lag Bolting

Question: 

Is lag bolting the bottom chord of a truss to the top plate of a wall a proper fix to correct truss arching, assuming the attic is properly vented?

Sealed Placement Plans

Question: 

Is it the responsibility of the truss manufacturer to provide a sealed layout drawing for roof trusses?

Main Wind Force Resisting Systems Vs Components Cladding

Question: 

As an engineer, I have noticed truss designers in some high wind states routinely using “Main Wind-Force Resisting Systems” wind pressure coefficients as opposed to “Components and Cladding” coefficients to design for wind uplift. A roof truss is not a main wind-force resisting system and would have to have a tributary area of more than 1000 sq. ft. before qualifying for the lower Primary Frame coefficients. In my experience this practice is routine.

Fire Cuts

Question: 

What type of construction uses a fire cut truss? Could you describe a fire cut truss?

Responsibilities With Lumberyards

Question: 

When you’re selling trusses through a lumberyard and the contractor calls to say that the “trusses don't fit correctly,” who has the ultimate responsibility for the trusses? I argue that the lumberyard is responsible since we have provided them with all the information on how the job was designed, even though they may or may not have passed this information on to the contractor.

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?

Truss Repairability

Question: 

Occasionally we deal with truss failures due to impact and or crushing forces such as trees falling onto roof structures. At what point can the truss no longer be repaired? Also, what should an adjuster look for when determining repair-ability? Or should a storm adjuster basically punt and call a consultant for every truss failure?