Design

Hanger Nails Above The Neutral Axis

Question: 

I recall seeing a design recommendation several years ago regarding installation of hanger nails above the neutral axis of the bottom chord of a plated girder truss. The intent was to avoid dumping large loads into the bottom chord, below the neutral axis. Can you tell me where I can find this information?

Drag Loads

Question: 

Can you explain drag loads and how to calculate a drag load pertaining to roof trusses?

Installing Valley Sets

Question: 

What are the requirements for installing “valley set” overlay 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?

Wind Loads From Solar Panels

Question: 

I am looking for information on point loading trusses. We manufacture mounting structures for solar panels. Typically, 10 to 15 sq. ft. of solar panel is supported by one standoff. Under extreme conditions – 50 lbs. per sq. ft. of wind load - we can transfer 500 to 750 lbs. of force onto one point of one truss. Are there any standards on this issue?

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.

Statistics On Truss Repairs

Question: 

How often are trusses repaired?

Truss Deflection Onto Non Load Bearing Walls

Question: 

I am installing a 40-foot scissor truss that is designed to deflect about ½ inch. I am concerned that the deflection will cause an interior partition wall to pick up some load from the truss and transfer it to the floor system. Should I double up the I-joists under this partition to pick up the extra load?

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?

Design Responsibilities

Question: 

My company supplied roof trusses for a hotel project. The building inspector shut the project down because the trusses were not designed to account for additional snowdrift loading. The construction plans did not contain any snowdrift loading information. The architect is claiming it is our responsibility to determine drift loading, therefore we must fix the problem. Do you have any documentation to help us dispute the architect’s claim?

Supporting the Arts

Ric Thompson, a senior truss designer with Millard Lumber, is used to taking on a challenge. “I don’t do small jobs,” he said. “I only do monsters.” Still, some monsters are more monstrous than others. Ask him about BLUEBARN Theatre, and it’s clear that this project stands out.