Last week when I saw Kaitlin’s post called “Old Sheetrock?” over on Preservation in Pink, I sent the link off as quick as a wink to a friend of mine down on the Coast who just loves old sheetrock. In fact, he would be an old sheetrock collector if only those pesky homeowners didn’t object so strongly to having chunks of their walls cut out. Anyway, he promptly sent me a couple of pictures of a picture of a sheetrock label taken in situ in a house in Waveland.
While Kaitlin’s label says “USG Sheetrock” (USG stands for U.S. Gypsum), the Waveland label is for Universal Gypsum and Lime Co.’s Gypsolite Wallboard, but as my friend notes (and he’s not at all a nerd for noticing this), both products seem to be based on the same manufacturing process first patented on July 11, 1912. That’s way earlier than I ever knew sheetrock existed.
Click on either picture to make it larger and more readable.
Mississippi played a role in the history and manufacture of gypsum board/sheetrock. According to a pretty detailed company history of U.S. Gypsum, U.S. Gypsum started diversifying in the late 1920s and bought up a manufacturing plant for insulating board at Greenville, Mississippi, in 1930 (I believe this plant still operates):
Avery [chairman of the board] took advantage of the company’s strong cash position at the beginning of the Depression to purchase nearly a dozen building material firms weakened by the economic downturn. In 1930 US Gypsum bought into the insulation board business with the purchase of the Greenville Insulating Board Corporation of Greenville, Mississippi. Also in 1930, it bought into the metal-lath business with the purchase of the Youngstown Pressed Steel Company of Warren, Ohio, and the metal-lath division of Northwestern Expanded Metal Company. Avery also made US Gypsum, which had already been in the lime business for 15 years, a leading lime producer in 1930 with the acquisition of lime-producing firms such as the Farnam Cheshire Lime Company. Producers of mineral wool and asphalt roofing acquired in 1933, and asbestos-cement siding acquired in 1937, rounded out the Depression-era acquisitions. The company countered the downturn in new construction by exploiting the remodeling and industrial markets.
The firm was apparently pretty secretive about their manufacturing process, because the 1931 Sanborn map for Greenville shows the plant property blank with the note that access was denied. On the 1951 update to the Sanborn, they show the buildings, but still note that access was denied and that the site plan is based on plans in the office.
Well this has been a pleasantly nerdy post for me, and I’ve learned alot, but it’s interesting to me that there doesn’t seem to be a good scholarly look at the sheetrock/gypsum industry and its effect on the history of building. Seems like a good thesis or at least a journal article.
Next, I need to rustle up pictures of rock-lath I seem to recall taking in Waveland–rock-lath is a gypsum material with small holes in it was used in place of wood lath and took a skim-coat of plaster. Unfortunately, rock-lath has the same problem as sheetrock, which is that it can’t take water like good ol’ plaster can, so the rock-lath I saw was all moldy from the flooding and was in the process of being torn out.





































Yeah, nerdy maybe, but that was a fun post! I didn’t know that sheetrock was that old either!
The house into which I just moved has been sheetrocked over the plaster– all of the trim is now flush with the walls which looks somewhat strange. It also makes picture-hanging somewhat difficult.
I hate that treatment–I’m gritting my teeth thinking about it. So common in the Jackson area though to try to cover the cracks from the foundation shifts.
You wrote, “rock-lath is a gypsum material with small holes in it was used in place of wood lath and took a skim-coat of plaster. ” That is exactly what is on the walls of my 1925-era house on Drummond Street in Vicksburg. The plaster is at least 1/2 inches thick, so the total wall thickness (above the studs) is about 1 inch. It has held up well over the years, but there are a few cracks that open up in exactly the same places every few years.
Beware that this older sheet rock may have asbestos fibers. Don’t sand or drill it.
Cool–so I guess it’s more than a “skim-coat”? That’s about the same thickness as plaster on a wood or metal lath. I suppose you’re probably opposed to donating a portion of your wall to research? :-)
As to the asbestos–I guess that’s why U.S. Gypsum shows up on this list: http://www.asbestosnews.com/asbestos-areas/mississippi.html
With holes on 4 inch square centres you don’t end up with as many keys as you do with wood or metal lath. Combined that with the fact that the plaster does not bind to the rock lath’s paper cover and you end up with a top coat that can fall off without much warning.
Rock lath might have worked better with more holes, but then you begin to compromise the integrity of the board.
Great post Mr. Malvaney!
Thanks Mr. Boyd, and welcome to MissPres! That’s a good insight into the problems of rock-lath. It seems like it was a good idea except maybe in practice.