Design

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?

Adding Tile To Existing Floor Trusses

Question: 

We are planning to add 1/2 in. cement board and 3/8 in. quarry tile to a kitchen floor. We need to know if the floor trusses will handle the additional weight. The floor trusses are 19.2 in. O.C. and the loading numbers are 40-10-0-5. What do these numbers mean?

Proper Bracing Of Valley Framing

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.

Responsibility Of Snow Drift Load Calculations

Question: 

Is the truss designer or the building designer responsible for calculating snow drift loads on a roof system?

Truss Attachment Information

Question: 

Would you please inform me of the specified requirements of the size and the amount of nail attachments from the truss to the top plate?

Temporary Bracing Documents

Question: 

Is it common practice for the supplier/distributor of a truss to provide a publication regarding temporary bracing with the delivery of the material?

Testing Wood Truss Strength

Question: 

We are building churches in Europe. These are modified pole barns and we are trying to use local materials and local volunteer labor. Since the truss is the heart of the building, I am looking for a method to test some completed trusses before the building is started to make sure they are strong enough.