Roof Trusses

Valley Sets

Question: 

What are the requirements for installing valley sets over 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? How can I calculate values for uplift resistance for the building inspector?

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?

Ga Rc 2601

Question: 

In RC 2601, is RC-1 Channel used?

Gable End Bracing

Question: 

Manufactured gable ends are actually frames even though they are often referred to as trusses. The webs are “studs” oriented vertically and usually spaced at 12, 16 or 24 in. O.C. The gable end frame is designed to transfer vertical loads from the roof to the continuous bearing wall below. Another way gable end frames are different from trusses placed in the interior of the structure is that frames experience perpendicular wind loads. The sheathed frame transfers the wind loads to the roof and ceiling diaphragms and vice versa.

Truss Design

Question: 

Recently, I was invited to view a newly-constructed 60 ft. by 36 ft. barn, with homemade big timber trusses as follows: 36 ft. span, 12/9 pitch, construction was 26 ft. 2x12 rafters, bracing 2x6, ceiling joists were 36 ft. boxed, 6x12 out of overlapping (6 ft.), 2x12 glued and nailed center, 16 feet of joist doubled as an 8 ft. high loft, floor trusses were on 12 ft. centers atop posts deeply anchored with good footings, roof and wall cross ties were 2x6 on edge every 24 in., floor cross ties in the loft were 2x8 on edge every 16 in., 4 ft. snow load.

Bracing Schematics

Question: 

Are there any schematics available on how to horizontally brace a 7/12 pitch roof?

Lumber Grades In Truss Design

Question: 

In truss manufacturing, can hemlock, fir and spruce be used instead of Douglas Fir/Larch? What grades can be used: Structural Light Framing (Select Structural through #3) only, or Light Framing (Construction through Utility) as well?

Drywall Cracking Under Scissors Trusses

Question: 

We keep having problems with dry wall joints raising on the vaulted bottom chords in the track homes that we are building. The joints run from front to back of the house and the trusses bear on the side walls. The trusses are mostly 2-point bearing (a few in the front and back of the building are tri-bearing). The trusses span 40 ft. and have a 4/12 pitch with a tile roof. Is it common to have dry wall problems as the trusses deflect? How long should the roof be loaded before hanging sheetrock? Should the heel of the truss be allowed to slide out on the top plate?

Industry Standards

Question: 

I am currently putting together a set of truss specifications for a set of structural plans. I am interested to know of the most current publication that may specify industry standards in truss components (i.e. metal connector plates, wood quality and connection quality). Do you have any suggestions?

Create A Ceiling Vault In Existing Rafter Roof

Question: 

Is it possible to retrofit a standard rafter/joist style roof to a scissors truss configuration without replacing the existing construction?