How to Shop for Drywall

A handyman in a plaid shirt measuring drywall in a home improvement store.

Getting ready to add drywall to your home? Shopping for drywall, also called Sheetrock, may seem like a simple task, but there's actually more to it than just knowing how much you need. There are other things to consider before you run to your local home improvement center to buy it, such as what type of drywall you need or what thickness it should be. To help you we created this little guide on how to shop for drywall.

What Type of Drywall Do do You Need?

Drywall and greenboard.

To start out, let's consider what drywall is. All drywall is made from the same thing: compressed gypsum (calcium sulfate dihydrate) plaster. This gypsum plaster mixture also referred to as plasterboard or Sheetrock, is formed into rigid sheets and covered on each side with thick paper. What makes any sheet of drywall different is simply what it is treated with. As for which kind of drywall you will need, there are four treatments or types of drywall and which one you will need will depend on where you'll be installing it.

The first and most commonly used drywall is simply known as drywall or Sheetrock. It's used mostly in residential interiors on walls and ceilings and comes in varying thicknesses.

The second type of drywall uses a paperless backing and is referred to as moldboard or mold-proof drywall. It's mold-resistant thanks to a special coating that helps to prevent mold from growing, and is good in mold-prone areas, but not high moisture areas.

The third type of drywall is referred to as moisture-resistant drywall. It can also be found by the name of greenboard or indoor tile backer board. This type is best used as a backer in areas that get wet, such as kitchens and bathrooms. In areas with high moisture, such as tub and shower surrounds, drywall should not be used. Instead, the cement board should be used in these areas and even though it can be at times referred to as drywall, it is not made of gypsum and is technically different.

The fourth and last type is fire resistant drywall and is referred to as Type X, fireboard, or x-board. Type X drywall is used when code calls for a fire rating to be followed, usually in commercial and multi-family homes. This drywall comes in the thickest form of 5/8 inch thickness, which means it's also good to use when sound control is wanted between rooms.

Drywall Sizes

A hand measuring drywall with a measuring tape and pencil.

The most common size of drywall, especially for residential use, is 4 x 8 feet. This size is the easiest to handle and hang. However, drywall comes in a range of lengths if longer is needed, and most stores carry sheets from 8-12 feet in length. Choosing which length you want is something that is completely up to the buyer. Using a longer sheet can help keep seams to a minimum and will create a nicer finished product, however, the longer sheets are also much heavier and more cumbersome to handle, especially if you're hanging it by yourself and best avoided in such circumstances.

Drywall Thickness

Drywall installation.

Drywall comes in many widths. The ½ and 3/8 inch thick drywall are the two most commonly used thicknesses used in homes. The thickness you choose will depend on what you'll be using it for as well as any local building code requirements. The thickness of drywall ranges from ¼ inch to ⅝ inches with the smaller being better for residential uses where thicker is better for commercial and multi-family construction use. The extra thick drywall can also be used in a home though, and it is often used when a fireboard is needed or for more sound control between rooms.

Local Building Codes

A stack of drywall.

Before you set foot in a store it would be wise to check your local building codes to ensure that you purchase the proper type and size of drywall. The type and size will vary according to the application. A simple check via a phone call or a visit to the website of your local building inspection department can help you know just what size and type may be required for whatever rooms you may be working with.

Now that you know how to shop for drywall, the only thing left is to know how much of it you will need. For this, you can check out our article on how to calculate how much drywall is needed or use an online drywall calculator. Once you have your list of sizes and types of drywall you'll need for each room, you can go shopping with confidence knowing that you'll get just what you need to properly complete any drywall project.