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2x4 laminated stud wall fire rating

Sleepy

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Does anyone know of a definitive source for info on fire rating of laminated 2x4 stud walls? The building was built in 1942 and has exits enclosed with laminated 2x4 studs (solid wood) with metal lath and plaster each side, or so say the drawings. IBC Table 721.1(2) has lots of antique assemblies listed, but not this one.
 
2 x 4's may be later than 42' ?

Glue Lam – History

Resin glues

When glued laminated timber was introduced to the building technology in the early twentieth century, casein glues, which are waterproof but have low shear strengths, were widely used. Joints with casein glues had detachment failures due to inherent stresses in the wood.

The invention of cold-curing synthetic resin glues in 1928 ("Kaurit") solved these problems - resin glues, which are inexpensive and easy to use, are waterproof and enable high adhesive strength. The development of resin glues contributed to the wide use of glued laminated timber construction.[12]


A significant development in the glulam industry was the introduction of fully water-resistant phenol-resorcinol adhesive in 1942. This allowed glulam to be used in exposed exterior environments without concern of gluline degradation.

By the early 1950s, there were at least a dozen manufacturers of glued-laminated timber in the United States. In 1952, these manufacturers joined to form the American Institute of Timber Construction (AITC).

The first U.S. manufacturing standard for glulam was published by the Department of Commerce in 1963.[2]:4 ?

This association sponsored the first national manufacturing standard in 1963, CS 253-63 Structural Glued-laminated Timber (10). AITC has continued to sponsor revisions to the standard. The first was PS 56-73 in 1973 that also became an ANSI standard, A190.1-1973. ANSI A190.1 was revised in 1982 and 1992. The latest version is known as ANSI/AITC A190.1-1992 (2).
 
Was this an old military base?

Yes, a military base. I think they are something called "nail laminated", so I don't think there is any glue. Some of the floor decks are laminated 2x as well, which I've seem before, but I'm struggling with classifying the walls for fire resistance. The walls were used to enclose stairs and elevator shafts.
 
So in fact they are not "laminated", only nailed to each other. If 2 x 4 net, what are they made of, 1x material? Are they set at 16" o.c? or flat edge to edge?
 
They are 2x4s set vertically side-by-side, wide faces together, and nailed together forming a solid wood partition that is then covered with metal lath and plaster on each side. Turns out, it is a recognized Heavy Timber assembly.
 
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