Floor Trusses

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?

Finger Jointed Lumber

Question: 

I market 2x4 and 2x6 structural finger-jointed lumber. As of now, we have strictly sold it as a #2 product. However, we ran some through a bender at a sawmill to test the modulus of elasticity and it looks promising. The equipment showed no recognition of the joint; it acted like regular lumber. We would like to go forward with this venture in the hopes of offering an alternative MSR to solid lumber that may also be more cost effective. What do you need to have from us to get your approval?

Cottonwood Lumber In Truss Construction

Question: 

I am developing a sustainable community in southeast Iowa. We have an abundance of cottonwoods nearby. I plan to have them sawn into dimensional lumber on the site and dry it there as well. I would like to use this material for trusses. A truss plate manufacturer informed me that because he had no data for cottonwood, he was unable to design trusses using it. Can you offer any advice?

Adequate Trusses

Question: 

Where can I find specs for what would be adequate trusses? I have a room with a 24 ft. span and my contractor is using trusses where the bottom plate is composed of 2x4s butted together and fastened with a metal plate. Is this ok?

Ga Rc 2601

Question: 

In RC 2601, is RC-1 Channel used?

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?

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?

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?

Floor Performance

Question: 

How do you avoid floor performance problems?

Lumber Substitution

Question: 

If the truss design drawing specifies using 2x4 1650F SPF, can 2x4 No. 2 southern pine be used instead? What are some things that need to be checked?