On a large building project, gymnasium, classroom,offices, shower, the spec’s called for borate treated lumber for all treated lumber plan notations.
The building is in the dry and insulation is in and drywallers are set to move in.
The contractor installed “treated sub-fascia” as well as “treated double plates” at the top track of the steel stud wall system. The metal fascia cover suppliers called for a barrier to be placed between their product and treated wood products.
The on-site observer called out the lack of barrier to the general contractor’s superintendent and was promptly refuted by indicating that the sub-fascia was borate treated and did not need a barrier. The superintendent was asked to remove the installed fascia covering and install the barriier (30# felt).
I was called to job site to examine the situation and found that the lumber in question appearred too dark a green to be borate treated. I was also able to collect treater labels fron the ends of installed timbers and some off-fall. All were labeled ACQ.
When I pointed this out to the super he replied that ACQ was the same as borate! I informed him of his error. Then the super had some fascia cover that was installed last week, removed and the backside paint had already blistered and corrosion had begun.
The discussion then moved to the treated double top plate of the steel stud perimeter wall system. No separation membrane there either, nor were the fasteners rated for ACQ. Those walls now carry the ends of 50′ 6/12 roof trusses with a completed roof installed with attic mechanical room, and tied into the cmu sidewall of the gym.
An interior treated window stool blocking was removed to determine if any corrosion had occurred. After being install 3-4 weeks in the dry-shell the fasteners and steel stud members showed corrosion.
Does anyone know of an injectable material that would protect the steel stud tract that is now setting against the ACQ plates?
Jacking and inserting a membrane would be a horrific task!
Any suggestions?/Comments!………………….Iron Helix