WHY AMERICAN HOMES STOPPED GETTING PLASTERED

Old-style lath and plaster construction, seen
from the back of the wall. The plaster squeezed
between the laths formed a "key" that held
the finish to the wall—or occasionally, not.

Perhaps the most singular trait of American homes is the flimsy, cereal-box thud of our gypsum board walls. No one else in the world has anything quite like them—and I don't mean that as a compliment. Mind you, if it weren’t for World War II, our walls might not sound quite so hollow.  

Before the war, American homes were routinely plastered inside--a painstaking process that first required nailing thousands of feet of wooden strips known as lath to the ceiling and walls of every room.  

Things you can do with plaster that you can't with drywall.
All those movie palace interiors of the 1920a weren't really
built with stone, marble, and gilt, but with painted plaster.

The lath was covered with a coarse layer of plaster called the “scratch coat”.  The wet plaster squeezed through the gaps in the lath, locking it to the walls and ceiling.  Days later, when the scratch coat was dry, a second “brown coat” was applied to make the surfaces roughly flat. This, too, had to dry for several days.  Last came the “skim coat”, a thin layer of pure white plaster that produced a smooth finished surface, something like the cream cheese topping does on a cheesecake.  

Early ad for Sheetrock, before World War II gave
U.S. Gypsum the market opening they were looking for.

Depending on the weather, this process could take days or weeks, during which no other trade could work inside the house. This was how plasterwork had been done for centuries, and there seemed no reason to change.  

Then came World War II, and with it an urgent need for military structures ranging from barracks to whole bases. Faced with shortages of both labor and material, Uncle Sam was desperate to find faster and cheaper ways to build. And since beauty was not much of an issue, eliminating plaster was an obvious starting point.

Levittown, New York under construction, circa 1946.

Enter the United States Gypsum Company, which way back in 1916 had invented a building board made of gypsum sandwiched between sheets of tough paper. After more than two decades, the product they called Sheetrock still hadn’t really caught on. Even its successful use in most of the buildings at the Chicago’s World’s Fair of 1933-34 didn’t do much for sales.  But the urgencies of wartime construction changed all that.  

As the government soon came to appreciate, Sheetrock did away with the need for wood lath, multiple plaster coats, and days and days of drying time (hence its generic name, “drywall”).  Installation was simple: After the 4x8 sheets were nailed up, the nail holes were filled, paper tape was used to cover the joints, and a textured coating was troweled on to help disguise the defects.

Gypsum board walls: They feel like cardboard, because
they are partly cardboard.

Of course, all this was only meant as a stopgap replacement for plaster, but as you’ve probably guessed, it didn’t turn out that way. By the war’s end, many builders who’d gotten used to slapping up drywall were suddenly reluctant to go back to the trouble and expense of plastering. 

What’s more, Sheetrock’s arrival coincided with the rise of modern architecture, which preferred plain, flat surfaces to the fussy moldings and reveals of prewar styles. To Modernist tastes, the fact that Sheetrock couldn’t be molded the way wet plaster could was hardly a drawback. People seemed more dismayed by the flimsy cardboardish sound of the walls in their postwar homes, but they soon got used to it.

U.S. Gypsum would like you to remember that
"Sheetrock" is their trademark, even though it's become
a virtual synonym for gypsum wallboard.

Flimsy or not, there’s no doubt that Sheetrock proved a huge boon to the postwar housing industry. Prior to the war, the typical American developer built about four houses a year.  By the late Forties, a developer like the legendary Bill Levitt was able to churn out 17,000 tract homes at Long Island’s Levittown, sell them for $7,990 , and still make a thousand dollars profit on each. Mass production was the key to the postwar housing boom, and Sheetrock helped make it happen.  

Just something to bear in mind next time your kids smash a doorknob through the bedroom wall.