Engineering

Attachment Of Scissors Trusses

Question: 

What is the correct method of attaching scissors trusses to the top plate? I read recently in a trade magazine that this type of truss should be toe-nailed on one end and attached with slotted clips on the other end. According to the article, this is to allow for movement of the truss. We require PE stamped spec sheets from the truss manufacturer to verify trusses meet wind and snow loads. These sheets give bracing requirements but never give recommended attachment requirements.

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.

Retrofitted Shed Dormer

Question: 

I own and live in the middle unit of a one-story tri-plex that has a truss-framed roof. The interior has high ceilings that would potentially allow the addition of a second floor room. I am contemplating adding a shed dormer to create a second story bedroom. Do you have any suggestions as to how a shed dormer could be added? I am familiar with how to frame up a shed dormer if the original framing were rafters and a ridge board, but the truss construction has thrown me for a loop.

Liability Issues With Lvl Beams

Question: 

We have been specifying laminated veneer lumber (LVL) beams for some time now. The plans usually state, “Beam to be engineered and supplied by truss manufacturer.” What kind of liability issues do I need to watch out for?

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?

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?

Installation Guidelines

Question: 

What are the requirements on the permanent bracing of bottom chords? Can gypsum board diaphragms be used?

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.

Statistics On Truss Repairs

Question: 

How often are trusses repaired?

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?