Lumber

Turb O Webs

Question: 

We have been using Turb-O-Webs for about four months. We are very happy with their performance, although there have been a few ripples along the way. The main thing that concerns me at present is the need for performance documentation and testing data. Do you have anything that will help, or know of people or organizations that could offer assistance?

Duct And Light Penetrations Of Fire Rated Assemblies

Question: 

In a small scale multi-family residential project, I'd like to use a wood truss floor-ceiling assembly to achieve a one hour separation between units. I'd like to directly attach the drywall to the underside of the trusses & use the truss space for ducts & lighting (the floor above will be lightweight concrete on plywood sub-floor). UL assemblies do not seem to address the duct/light penetrations in such an assembly. Can I achieve a one-hour rating in such an assembly and how are penetrations addressed? Can the ducts in the truss space serve both units above and below?

Lumber Species

Question: 

What type of wood is usually used for wood trusses? I live in Louisiana and I would guess pine, but I want to make sure.

Grade Marked Lumber

Question: 

When webs are cut is it alright that sometimes the grade mark is removed? From a liability standpoint, what is the rule with grade marks and web members?

Fire Rating For Truss Assemblies Built With 2x3 Lumber

Question: 

Are there any published studies or guidelines on the fire rating of floor trusses built with 2x3 lumber?

Repairs To Field Modified Damaged Trusses

Question: 

As a home inspector, I have recently inspected an existing home with an attic truss system installed. Several of the truss web members have been cut away to allow access to an attic-mounted heating system. Can you recommend repairs to a truss with cut web members?

Fire Damage Assessment

Question: 

How do you evaluate whether a metal plate connected truss is still usable after exposure to fire? Are there any recommended tests?

Structural Composite Lumber In Trusses

Question: 

The lumber used in most metal plate connected wood trusses is either visually- or mechanically-graded solid sawn dimensional lumber. However, the Truss Plate Institute's ANSI/TPI 1 allows the use of structural composite lumber (SCL) products such as laminated veneer lumber (LVL), laminated strand lumber (LSL) and parallel strand lumber (PSL). These engineered wood products can conceivably compete with sawn lumber and complement it in truss designs.

Floor Performance

Question: 

How do you avoid floor performance problems?

Truss Design Factors Of Safety

Question: 

I am currently working on a project where a wood truss system was loaded with a heavy spring snow. I do not believe the load was beyond the truss's design capacity, but how do you know? Is there safety built into wood trusses? If the trusses were loaded beyond their design capacity, it would not have been for a long duration.