Materials

Question: 

I am trying to determine the manufacturer of some wood trusses installed in the early 1980s in New Jersey. The stamp mark on the connector plates reads, to the best of my ability, TPL-153A (it could be PPL or TPI, but I am unsure). I need to get in contact with this truss manufacturer in order to determine design loads for the truss, as I am remodeling the store under the roof.

Question: 

What is the life expectancy of wood that was used in an attic truss? Does fire retardant change the life expectancy?

Question: 

I would like to know if there is an age restriction on wood trusses. How long after production are they safe to use? The trusses in question are at least three to four months old. Are they still safe to use? They have not been covered the entire time and are showing signs of age.

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.

Question: 

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

Question: 

I am currently undertaking a project dealing with techniques and methods of joining structural timber members. Do you have any available information on timber connections like split rings and design software?

Question: 

Where can I find tolerances and measurements of green and dry lumber?

Question: 

We recently received bids on a school project, which referenced UL P523. This assembly used light-gauge steel trusses. We noted on the drawing that we could accept an alternate design using wood trusses in lieu of light-gauge steel framing, if the alternate design could meet the fire ratings.

Question: 

I am investigating an existing wood truss. The pressed plates used are stamped with “Combo Lock.” Do you happen to have any information on them? From what I have been able to determine, they have not been readily used in the last 10 to 15 years.

Question: 

I need to obtain some information on fire-retardant-treated roof trusses.