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Drywall Thickness for Bathroom (All You Need to Know)

In many cases, people use drywall for their bathroom walls because it is a relatively thin and often less expensive material. However, the thickness of the drywall needs to be appropriate for a well-organized bathroom. 

If you want to choose the right drywall thickness for your bathroom, you should consider a few factors.

Drywall thickness for bathroom

As a general rule, thicker walls will usually resist water penetration better than thinner walls and will also prove to be more durable. The thickness of the drywall in most bathrooms should be 1/2 inch. The ceiling should also be 1/2 inch thick. Floors and trim usually need a 1-inch thickness.

A bathroom’s drywall thickness is primarily determined by three factors: water intrusion, bathroom heat, and bathroom humidity. Water intrusion is primarily determined by the thickness and resistance of the drywall to moisture penetration. 

Thinner walls are more likely to be penetrated than thicker ones. Bathrooms with high moisture content (such as showers) benefit from greater resistance to water penetration.  

Heat also plays a role in determining Drywall thickness for bathrooms. A layer of insulation between the Drywall and the Floor or Ceiling will help regulate the temperature in your bathroom. A thick layer of drywall also resists heat transfer.

A bathroom’s humidity is primarily determined by the thickness of the drywall and how well it dissipates moisture.

A 1/2-inch-thick drywall layer will generally provide adequate protection from bathroom humidity, but a slightly thicker layer may be required in particularly humid environments. Drywall that is 1/2 inch thick will serve as a good general rule of thumb for most bathrooms.


In most cases, a thickness of 1/2 inch should be enough for bathroom walls. In contrast, a 1-inch thickness may be more appropriate for floors and trim. 

For bathrooms with high moisture content, thicker Drywall can also provide a layer of insulation due to its resistance to water penetration and bathroom heat.


A layer of insulation between the drywall and ceiling will help regulate the temperature in the bathroom. Heat can also be prevented from transferring from a thick wall to a floor or toilet by installing thick drywall. 

Typically, a 1/2-inch thickness is sufficient for ceilings in bathrooms. Since drywall thickness for the bathroom plays a critical role in comfort and function, choosing the correct thickness is important.

Is it OK to use regular drywall in the bathroom?

Due to its low moisture barrier ability and potential for water penetration, regular Drywall is not recommended for bathrooms. The reason for this is that regular Drywall, like most building materials, does not contain many cellulose fibers, which prevent moisture from absorbing.

Because of this, even if you seal the seams of Regular Drywall with tape or caulk, moisture will still seep through the cracks and cause mildew growth and damage to your bathroom’s finishes.

Furthermore, Regular Drywall can cause problems with heat and moisture transfer in bathrooms. Regular Drywall is so thin that it is not very effective at blocking out light or air circulation, which can increase the risk of condensation and mold growth.

However, if regular Drywall is necessary for a bathroom, choose the thinnest version available and install it with proper techniques to prevent moisture loss and water penetration.

Bathroom drywall thickness code

Following the International Building Code (IBC), penetrating drywall in a bathroom shall not penetrate more than 1/2 inch (12.7 millimeters). A variety of thicknesses of drywall are available: 3/8″, 1/2″, and 5/8″, metric 6-, 9.5-, and 12.7-mm.

US drywall has a standard thickness of 1/2 inch (12.7mm), while the other two thicknesses are non-standard. There are also some requirements for standard thickness in building codes. 

Following OSHA, the maximum thickness for single-layer Drywall in bathroom applications shall be 1/2in (12.7mm). For double and triple layers, the thickness is 3/8in (9.5mm). Water infiltration can be prevented by sealing or taping the seams as described herein.

A wall constructed with a thickness greater than 0.5 inches (12 mm) is considered safe for use in bathrooms and other wet areas. To ensure the safety of your home, it is important to follow building codes. 

7 factors that affect the drywall thickness for bathroom

To provide adequate insulation and soundproofing, bathroom walls should be as thin as possible. For bathrooms, the thickness of drywall can vary depending on a variety of factors, such as:

Type of substrate:

As a substrate for drywall, concrete, and masonry are often used. It is important to note that the thickness of drywall will vary depending on the type of substrate it is placed on.

Type of Drywall:

A standard drywall thickness is 3/8 inch, 9.5 mm, a nonstandard thickness is 1/2 inch, 12.7 mm, and a double thickness is available for added insulation and soundproofing. For proper installation of thicker drywall, a higher quality tape is also required. 

In addition to being more expensive to install, thicker drywall is also more difficult to work with.

The age of your home:

It is also possible for the thickness of the drywall to increase over time within your home. For new construction, bathroom walls can be as thick as 3/8 inch, but more commonly 1/2 inch or 12.7 mm for older homes. 

In a home age, heavier materials are used, resulting in greater thicknesses of structural support materials.


There may be some areas in your bathroom that require thicker drywall than others. It is often the case that areas near plumbing and heating registers are at a higher risk of water damage, and they need to have a thinner wall to ensure good insulation and proper air circulation. 

To prevent stress and damage in areas that are more frequently used, it is also recommended to have a thicker wall in these areas.

Number and size of windows/doors:

You may need to increase the thickness of drywall in your bathroom if there are a lot of windows or doors. For proper installation of drywall, it is necessary to use thicker drywall in areas where windows and doors are located to avoid stress on walls.

The layout of the studs in the wall:

Depending on the layout of the studs in your bathroom wall, the thickness of the drywall will also differ depending on the layout of the studs. 

When a wall has a lot of open space between the studs, it may be necessary for the drywall to be thicker to ensure that it will provide extra structural support.

The type of fasteners and the moisture content of the drywall:

The thickness of drywall also depends on the type of fasteners used and the moisture content. Tape of higher quality is generally required for proper installation of thicker drywall. 

Nevertheless, brittle drywall or drywall with a lot of moisture trapped inside may not withstand heavy use and will require thicker material.

What is the best drywall to use in a bathroom?

Several types of drywalls can be used in bathrooms, including gypsum board, mineral fiberboard, mud drywall, and green drywall. The various types of Dry Walls each offer their advantages and should be used accordingly depending on the bathroom’s needs.

Green drywall:

Drywall made from recycled materials is called green drywall. In areas prone to water damage like bathroom walls where water damage can be a problem, this product can be used because it has excellent moisture resistance.

Gypsum board:

A gypsum board is one of the most popular types of drywalls for bathrooms because of its relatively light weight and ease of installation. 

Even though the gypsum board is a good quality board in terms of thickness and moisture resistance, it may not hold up well to heavy use or weathering over the long run.

Mineral fiberboard:

Mineral fiberboard is another lightweight Drywall material that is popular for bathroom walls due to its excellent thermal insulation. Furthermore, mineral fiberboard resists moisture and decay, which makes it a good choice for areas with a high level of humidity.

Mud Drywall:

Dry mud drywall is made from clay and dried mud mixtures. Although this type of drywall is heavier than others, it’s moisture-resistant and thick, so it’s a good choice for bathrooms where water damage is a concern or the wall will be subjected to heavy use.

Tape Drywall:

The tape drywall version of drywall is made from thin sheets of a material that looks like paper and is placed on the wall. Although it’s not as durable as other types of Drywalls, the good thing about it is its lightweight and its ease of installation for bathrooms.

Final Thoughts

In conclusion, it is recommended that the bathroom be finished with a 1/2-inch (12mm) drywall and a 1/2-inch ceiling. For bathrooms, do not use regular drywall. You should use mud drywall, gypsum board, or green drywall for bathrooms. Select drywall based on your home’s substrate, age, and size.