The short answer
Most people think drywall is just drywall. It's the white board that goes up on your walls and ceilings, and for a lot of the house, that's exactly what it is. But there are a handful of different types of drywall, each built for a specific job, and using the right one is the difference between a wall that lasts and a wall that fails early.
The main types of drywall are standard board, moisture-resistant board, mold-resistant board, cement board, and fire-rated Type X. On top of that, drywall comes in a few thicknesses, and the thickness matters as much as the type. We'll go through all of it below in plain language, so you know what's going on your walls before the truck shows up.
Drywall thickness: from 1/4-inch to 5/8-inch
Drywall comes in four common thicknesses. The thicker the board, the heavier and stiffer it is, and the more it costs. Here's how they stack up and where each one gets used.
The thin one. Bends around curved walls and arches, or goes over an existing surface as a fresh skim layer.
A remodel and repair thickness. Handy for patching or going over old plaster without building the wall out too far.
The standard. Most interior walls and ceilings in your home are 1/2-inch drywall. It's the everyday board.
The heavy hitter. Ceilings, fire-rated Type X for garages, and rooms where you want less sound coming through.
For a normal wall, 1/2-inch is the answer almost every time. Ceilings often step up to 5/8-inch because the extra stiffness keeps them from sagging between the framing, especially under a heavy texture. And when code calls for fire protection, 5/8-inch Type X is what goes up. More on that below.
Standard drywall (white board)
Standard drywall is the white board you picture when you think of drywall. It's a gypsum core wrapped in paper, and it's what covers the majority of the walls and ceilings in most homes. You'll also hear it called Sheetrock, which is just a well-known brand name for the same thing.
Standard board is the least expensive type and the right call anywhere you don't have moisture, fire, or sound to worry about. Bedrooms, living rooms, hallways, closets, and most dining and family spaces all get standard drywall. When our crew hangs a new home in Ridgefield or Battle Ground, standard 1/2-inch board covers most of the square footage, and the specialty boards go in only where they're needed.
Moisture-resistant drywall (green board)
Moisture-resistant drywall is easy to spot because of its green paper facing, which is why everyone calls it green board. That facing is treated to resist humidity and the occasional splash, so the board holds up in damp rooms where standard drywall would eventually soften and fail.
Green board belongs on bathroom walls and ceilings outside the shower, in laundry rooms, and near kitchen sinks. Here's the part people miss. Green board is water-resistant, not waterproof. It handles humidity, but it can't sit soaking wet, so it does not go behind shower or tub tile. That's a job for cement board, which we'll get to. Our bathroom drywall guide maps out the whole wet room.
Mold-resistant drywall (purple board)
Mold-resistant drywall takes moisture protection a step further. Instead of a paper face that mold can feed on, it uses a treated or fiberglass facing that mold has a hard time growing on. It often shows up with a purple face, so purple board is the nickname.
This is the board we reach for in the rooms most likely to see moisture over the years. Full bathrooms, basements, and utility rooms in a wet climate like ours. Around Camas and across Clark County, the damp season is long, and mold-resistant board buys you real peace of mind in the rooms that need it. It costs more than green board, so we use it where the risk earns it rather than everywhere.
Cement board for showers and wet areas
Cement board isn't technically drywall, but it belongs in this list because it's the board that goes where drywall shouldn't. It's a rigid panel made with cement and reinforcing fibers, and it doesn't care about water at all. That makes it the correct backer behind tile in a shower or tub surround.
If someone tries to put green board behind your shower tile, that's a corner being cut. Standard and moisture-resistant drywall both break down when they stay wet, and a tiled shower wall stays wet. Cement board is built to live in that zone for the life of the bathroom. When we build out a wet area, cement board is what goes behind the tile, every time.
Fire-rated drywall (Type X)
Fire-rated drywall, known as Type X, has a denser core packed with glass fibers that slow how fast fire can burn through it. It's almost always 5/8-inch, and it's not a nice-to-have. In specific spots, building code requires it.
The most common place a homeowner runs into Type X is the garage. When a garage shares a wall or ceiling with the living space, code calls for fire-rated board on that separation to buy time if a fire starts. It also shows up between attached units and around certain mechanical rooms. If you're finishing a garage, this is not the place to guess. Our garage drywall guide covers the fire-separation rules, and our post on drywall permits and code in Vancouver, WA gets into when an inspector is involved.
Lightweight drywall for ceilings
Lightweight drywall is standard board's easier-to-handle cousin. It's a 1/2-inch board engineered to weigh noticeably less than regular 1/2-inch, which makes a real difference overhead. Hanging a ceiling all day is hard on a crew, and lighter board that still resists sagging is a genuine upgrade for ceiling work.
For you as the homeowner, the finished result looks the same as standard board. The benefit is on the install side, where lighter sheets mean cleaner ceiling work and less fatigue on a long job. It's one of those quiet improvements in drywall that most people never hear about.
Which type of drywall goes where
Here's the quick version you can keep in your back pocket. This is how we spec board on a typical home.
| Type of drywall | Best for | Good to know |
|---|---|---|
| Standard (1/2") | Most walls, bedrooms, living areas, hallways | The default board and the lowest cost |
| Moisture-resistant (green) | Bathroom walls and ceilings, laundry, near sinks | Water-resistant, not waterproof. Not behind tile |
| Mold-resistant (purple) | Full baths, basements, humid rooms | Facing mold struggles to grow on. Costs more |
| Cement board | Behind shower and tub tile, wet zones | Not drywall, but the right backer for tile |
| Fire-rated Type X (5/8") | Garage separation walls and ceilings | Code required in many spots. Not optional |
| Ceilings (5/8" or lightweight) | Ceilings, especially under texture | Stiffer board sags less overhead |
You don't have to memorize any of this. A good drywall crew specs the right board for each room as part of the job. But knowing the basics means you can ask the right question when someone hands you a quote, and you'll know whether the bathroom is getting the board it should.
AvilaCo Drywall handles drywall installation for homes across Clark County, and we spec the right type of drywall for every room, from standard board in the bedrooms to cement board behind the shower tile. If you're planning a build or remodel around Washougal or anywhere in the area, our guide on what to know before your drywall installation is a good next read. Ready to talk through a project? Reach out for a free estimate or call us at (360) 904-3878.
