Floor Trusses

Installation Guidelines

Question: 

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

Use Of Metal Plate Connected Wood Trusses In IBC Jurisdictions

Question: 

IBC 2012/2015 2303.4.6 and IBC 2012/2015 2303.4.7 state: 
2303.4.6 TPI 1 specifications. In addition to Sections 2303.4.1 through 2303.4.5, the design, manufacture and quality assurance of metal-plate-connected wood trusses shall be in accordance with TPI 1. Job-site inspections shall be in compliance with Section 110.4, as applicable.

Determining Necessary Truss Height

Question: 

How high would a truss have to be to span 33 feet 9 inches?

Fire Damaged Trusses

Question: 

I have been hired by an insurance company to determine the extent of damage to roof trusses exposed to fire. How much fire damage compromises the structural integrity of the truss?

Remedy For Bouncy Floor Trusses

Question: 

We are experiencing problems with bouncy wood floor trusses. I'm wondering what the industry standard is on deflections (live and total load). Also, do you have any ideas on how to decrease the deflection without affecting the profit margin significantly?

Vent Sizes

Question: 

I have mono trusses on either side of a firewall. I have the fire rating/wall material between them. Can I place a ridge vent above these two? Or should I use vents? How do I calculate the appropriate vent sizes and styles?

Chase Placement In Floor Trusses

Question: 

Is there a general rule of thumb to follow on chase placement within a top-chord bearing floor truss? In other words, how close to the bearing point of the truss can the chase occur?

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?

Penetration Of Fire Walls

Question: 

Can a roof truss penetrate a one-hr. tenant separation wall without having a one-hr. rated ceiling? The building official insists that the 2x4 chords are combustible and nullify the integrity of the one-hr. rated partition that is constructed in an attic above an 8 in. C.M.U. bearing wall. The partition consists of gypsum board attached to 2 x 4 stud framing. The building official insists that a ledger must be attached through the gypsum board to support the trusses each side of the wall. This is almost saying that any rated assembly must have bearing only on other rated assemblies.

Truss History

Question: 

How long has the truss industry been around and where did it start?