reinforce back side lath and plaster walls

It's interesting to note that the Corner Rite was only nailed to one side of the inside corner and only enough to hold the material in place until it was bedded in the plaster.Ĭorner Rite is pretty easy to tear through with a wide chisel or a flatbar. While a rock lath and plaster job did not use any tape or metal to cover the joints in the rock lath, they did use the Corner Rite on the inside corners. The purpose of the Corner Rite is to prevent cracks along inside corners, much like we do with joint tape today. The metal you see in your example is called 'Corner Rite' it is a black coated expanded metal 90 degree corner. This allowed the plasterer to strike off his job flush with the strip of wood at these critical areas giving the finish guy a nice even plane to apply his casings and trim to. To ensure that the thickness of the plaster was uniform around windows, doors and along the baseboards, a 3/4 x 3/4 strip of wood (usually redwood) called a Plaster Ground was nailed. The lath is 3/8 and the plaster and lime is 3/8. The typical finished thickness of this system in 3/4 inch. That's the coat that everyone sees and refers to as plaster. On top of the gypsum plaster coat, a coat of white hydrated finish lime was applied. Over this material, a coat of gypsum plaster was applied. The material is 16 x 48 x 3/8' thick and was nailed to the studs in a running bond or 'brick' pattern. The rock lath you have there is a product that took the place of old wood lath. Rock lath and plaster finishes were sort of an evolutionary step to where we are today with blueboard and skim coat plaster jobs. What you have there is a rock lath and plaster job.

Reinforce back side lath and plaster walls