What Is the Thinnest Drywall You Can Buy?

Drywall is a building material used all over the world to create the smooth walls we see in almost every home in the U.S.
Drywall replaced the old-fashioned plaster for covering wood framed buildings because it is so quick and easy to install. Professionals can install an entire house in a couple of days, compared to the week or more it would take them to install plaster. It is also easier to repair.
It is made of the mineral gypsum, compressed and sandwiched between two sheets of heavy paper. Drywall is also called gypsum board, wallboard and plasterboard. Some people refer to is as Sheetrock, though that is actually a brand name.

Types

Fireproofing: Drywall is a natural fireproofing material because gypsum resists burning. The thicker the board, the more fire-resistant it is.
Sound-proofing: Thicker boards are also better insulators against heat, cold and sound. There are specific sound proofing drywall boards that contain wood or other material to help dampen sound.
Water- and mold-resistant: Boards made with a wax or oil component in the paper are used in bathrooms and showers to resist moisture.
Radiation barriers: Some wallboard includes a layer of lead to block radiation, as in a lab or hospital with x-ray machines.
The Gypsum Association, a nonprofit trade association representing wallboard manufacturers in the U.S. offers the following guidelines for using the different thicknesses available.

1/4-inch thickness

This is the thinnest type of wallboard. Use it as a base when you are layering wallboard for soundproofing, or to put over existing walls when you are remodeling, and don't want to demolish what's there. It's also good for curved walls.

5/16 inch thickness

Prefabricated and manufactured houses often use this thickness because it is more rigid than 1/4-inch but lighter than 1/2-inch.

3/8-inch thickness

Use this as the top layer in a double layer system, such as over an existing wall if you are remodeling.

1/2-inch thickness

This is what we see in most standard houses. Use it in a single layer over your wood framing for new construction or remodeling. You can also use it with any of the other thicknesses in a layered system for sound-proofing.

5/8-inch thickness

You'll see this in some commercial buildings and in high-end homes. The added thickness makes it even more fire-resistant and stronger for impact-resistance. Some builders layer it with thinner board for super impact, fire-proofing and sound-proofing.

3/4-inch thickness

This board is used much like the 5/8-inch board.

Sometimes contractors use 1-inch thick wall board (the thickest available) for stairwells, chases and interior wall partitions. This comes in smaller panels.