Roof Trusses

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.

Transforming Attic Into Living Space

Question: 

We are looking into developing the attic space above our garage into a media room. The garage is attached to the home and we would enter this area from the living room. We recently read if you have a truss system that in order to develop the attic, one would have to replace the entire roof with conventional construction. My question is: can we safely develop this trussed area above our garage?

One Hour Roof Ceiling Assembly

Question: 

I am looking for a 1-hour roof/ceiling assembly for wood truss construction. I would like to apply the drywall directly to the bottom of the truss and also have insulation for sound control. Is this possible without using channels and what UL number would I use?

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?

Shimming Or Shaving Variances In Truss Dimensions

Question: 

If you have the condition where you are out by the max tolerances of 1/2 in., how do you correct the situation? Do you shim the truss from the bottom? Shim from the top? I will assume you do not shave the truss off. What is the published corrective action for situations that cannot handle the variation in truss height?

Old Fire Retardant Treated Lumber

Question: 

I have recently heard of a problem with fire-retardant-treated wood (FRTW) trusses that were manufactured and installed in 1965-1980. I was searching for more information, since my job involves the protection of property in our member school districts. I had heard that the trusses make of FRTW during that time period can or will become corrosive to the hardware and the trusses will fail.

Comparison Of Stick And Component Framing

Question: 

Does SBCA produce any products detailing how to market and sell roof and floor trusses to builders for whom stick framing has been the standard way of building? Products that detail the cost savings when compared to traditional stick framing?

Determining Earthquake Loads

Question: 

We are currently developing a project which specifies “Seismic Design Category C.” We are an East Coast truss manufacturer and have not encountered seismic requirements before.

Safety Issues With Design Dead Loads

Question: 

Can I safely install 3/4 in. T&G, OSB on 2x4 trusses that are 24 in. O.C.? My roof was installed over 5/8 in. plywood without clips that have caused a lot of sagging and the shingles need replacing. I want to “fix” it one time and install architecture type shingles, but the garage is 24 ft. wide and 28 ft. long without any load bearing walls. My concern is the weight on the trusses. 5/8 in. plywood weighs 52 lbs. and the OSB weighs 78 lbs. for each 4 ft. x 8 ft. sheet. The roof will require about 84 4 ft. x 8 ft. sheets to cover, which equals about 2,184 lbs.

Spacing Requirements On Sheathing

Question: 

I am looking for help on the spacing required to screw down a BHP B-36 20 gage roof deck to wooden trusses spaced at 5 ft. 4 in. O.C. and 24 in. O.C. Do you know of any published codes or specifications on the above?