Plaster has been used for over a century on interior walls as a finish coat. It can be spread over stone, wood, even straw as has been demonstrated with straw bale homes. Plaster coating interior walls has come back in a big way in the higher end home market. The differences in old plastering methods versus new plastering methods may surprise you.
The Old Methods Of Plastering Walls
In the 1800’s and 1900’s, any wood framed structure that had a finished wall surface was typically made out of plaster. In order for the plaster to stick to walls however, it had to have something that would keep the plaster in place. Lathe boards, about 1/4 inch thick were nailed to the wall framing about 1/2 inch apart, horizontally. When plaster was applied to the wall, it was put in an inch thick pile on a board and pushed into the wall. The plaster would then squish in between the boards creating a key that when dry would lock the plaster to the boards. This took a lot of plaster.
In the late 1920’s plaster board was developed to make the interior construction faster and cheaper. Plaster board has multiple holes roughly 3/4 of an inch in diameter that take the place of the lathe, with about 1/4 of the time to install it. The plaster board has the added benefit of being about 1/2 inch thick and with the plaster coating on it, can be 3/4 of an inch or thicker making for a very strong interior wall system.
Modern Day Plastering
Today, plaster board is still used, but it no longer has holes in it for the plaster to bond to. Instead, the plaster board comes in solid sheets that vary in length to 20 feet long, but are either 4 feet or 54 inches in width. The type of plaster board that is used for full veneer plastering, is made out of fiberglass, which allows the plaster to grab onto the fiberglass compounds. The plaster is spread on in 1/8 to 1/4 inch coats in random patterns giving the wall an Italian texture. This texture is either left on, sanded off, or accentuated. All the seems are taped with fiber mesh tape which prevents cracking.
One of the biggest advantages of this type of plastering technique is the thickness of the plaster. Typical thicknesses range from 5/8 of an inch to 7/8 of an inch. Also, the dense fiberglass board has an R-value of R-5 to R-7 depending on the board, making it an energy efficient interior wall finishing system.
This has become a high end home mostly because of its more natural look, it’s substantive texture and feel, and it’s durability. The energy efficiency and sound attenuated qualities are just perks of this type of finish.