Before drywall became the standard finish, we used lath and plaster. Lath are rough, thin, narrow boards, nailed to the studs and ceiling joists with small spaces between them. A thick layer of coarse plaster was applied and forced through the gaps.
In Canada and the United States, wood lath and plaster remained in use until the process was replaced by transitional methods followed by drywall (the North American term for plasterboard) in the mid-twentieth century.
Plaster: A Traditional Approach
Plaster walls are harder and more durable than drywall, but they are also more expensive to install. In older homes, plaster was typically applied in three coats over wood or metal lath. Modern plastering methods often involve a single coat over a special drywall called a blue board.
Lath and plaster was a skilled craft and a time-consuming technique and the advent of cheaper, mass produced, pre-manufactured plasterboard meant lath and plaster largely fell out of favour by the 1930s and 1940s. Plasterboard was simply faster and less expensive to install.
Lath and plaster is an older construction technique widely used before the invention of drywall. This technique involves nailing narrow strips of wood (lath) to the framing of a building, and then applying multiple coats of a mixture of plaster and water.
The original product we call drywall today was Gypsum Board. The word gypsum is derived from the original Latin term gypsos, meaning plaster. A form of dry plasterboard was called gypsum. This was so named for the product of Gypsum used in its creation and manufacturing process.
Homes built before 1950 probably have plaster. Homes built between 1950 – 1969 might be plaster or drywall. Homes built after 1970 are probably drywall.
Once you've decided to replace your plaster walls, you'll need to identify the wall studs, scrape away the plaster, pry off the lath and remove your debris to clear the way for drywall installation.
Unfortunately, there wasn't a regulated or realistic way to ensure that all older buildings using plaster walls were asbestos-free. Asbestos was commonly added to plaster until the late 1980s, as it was seen as an inexpensive way to add to the plaster's insulation and fire-retardant properties.
Nails haven't been used to hang drywall since probably the 1970s, maybe early 80s.
PVC panels are impact-resistant, whereas drywall is prone to damage. Drywall contributes to landfill waste, decomposing into a pungent-smelling hydrogen sulfide gas. On the other hand, PVC panels are eco-friendly, have a low carbon footprint and can be recycled several times.
Most likely they settled unevenly or the foundation shifted over the years - highly unlikely that they were built crooked. But, possible that not all the angles were perfectly straight to begin with, as that is still the case in many building built today.
Wahoo Walls are made of non-organic materials that are unharmed by water and do not support the growth of mold. Made of JetBoard brand Magnesium Oxide adhered to an Integrity EPS by Atlas R-13 panel that is rated R-15/16 when used continuously without studs. These durable solid walls are fast and easy to install.
If the pin pokes into the wall easily, that's drywall. If it doesn't, then that's plaster. A pushpin can penetrate drywalls easily because they're softer compared to plaster. Meanwhile, lath and plaster walls won't even budge with a thumbtack unless you use a hammer.
One key difference between the two is that sheetrock is a brand name of drywall made by the United States Gypsum Corporation. Another difference lies in their production process; sheetrock has a slightly denser core than drywall due to the addition of a small amount of wood fiber to the gypsum core.
You can't identify asbestos sheetrock visually because it will look similar to modern alternatives. But among the signs that may indicate that your wall is made of sheetrock asbestos are if the building was built before the 1980s and if the walls are deteriorating.
The Consumer Product Safety Act of 1972 banned asbestos in artificial fireplace embers and wall patching compounds. The Toxic Substances Control Act of 1976 says the EPA can restrict substances including asbestos.
It will cost more than $10,000 to drywall over the walls of a 2,000-square-foot home. Let's say you've researched replacing lath and plaster with drywall and are confident in your ability to do it. The average cost to have drywall installed in place of plaster, if done by a professional is $1,020 to $2,800.
Lath consists of narrow strips of wood that attach to wood studs inside the wall or to ceiling joists. The plaster uses the lath for a base until it can dry and harden, forming the visible part of the wall. As long as you can find the studs under the plaster, you can hang drywall by screwing the sheets to these studs.
A best practice is to nail or screw the edges of the board, but only use screws in the field. Using adhesive for drywall reduces the need for screws in the field or middle of the board but some are still needed. Please check with local codes on what is recommended in your area.
Take a push pin and press it into your wall in a hidden area. Does it go in relatively easily? You likely have drywall. If it takes more effort (or doesn't go in at all, even with a hammer), it's probably plaster, concrete or brick.
Generally, a plasterboard wall will hold a TV securely and safely, but this is only as long as you use the right mounting. You should consider using an anchor or mounting plate for best results.
Plaster was the preferred ceiling finish material for structures built before the 1950s. However, as drywall became more widely available and affordable, it gradually replaced plaster in new construction.