Water-damaged plaster and lath wall section. Master craftsmen working on old houses around 1900 and earlier used plaster and lath to construct all interior walls. Lath was painstakingly nailed horizontally to vertical studs to grab the first plaster coat and hold it securely. Plaster walls were smooth and silky, and when cured were paintable. Plasterers were skilled craftsmen who worked long hours perfecting interior walls. Dampness and wetness will cause the plaster to crumble, although fresh plaster may be used to repair water damage and render it new again. Plaster was made and built to last more than a lifetime. Plaster and lath walls took 30 days to cure, although craftsmen advised waiting a period of a year before painting. For this reason, many homeowners chose to wallpaper their walls so as not to ruin the plaster work by painting too early. Plasterers were expensive 100 years ago; now they are extremely expensive and hard to find. Many new residents decide to tear down the old plaster and simply put drywall in its place as a cheap fix to save time and money. Plastering involved placing three layers on top of the other. The first coat stuck to the oak strips and was called scratch coat, which was troweled carefully into the lath to form a bond. The second coat was called brown coat, then a finish coat was applied thickly and pressed firmly to form a half-inch wall of silky-smooth lime plaster. Benefits of plastered walls include soundproofing not present with regular drywall. Plaster walls have durability not seen these days with gypsum or drywall, with plastered walls outlasting their owner and beyond. It's also easy to paint, wallpaper or repair minor damage.