How Thick Should Walls Be Overview
What is the standard thickness of an exterior wall?
In general, the standard thickness of an exterior wall is 6 inches. However, using this as a basis for comparing different states and building codes is not advisable because there are no universal guidelines for the thickness of exterior walls.

The exterior wall thickness may change depending on various factors, such as the local building codes, climate, and geological factors. For example, many homes in colder climates need an additional layer of insulation to stop the air from penetrating through the walls.
There’s no consensus on what the standard thickness of an exterior wall is, but generally, a common rule of thumb is to make them 6 inches thick for safety.
What is the standard wall thickness in a residential home?
There are no set standards for residential homes, but they usually range from 2 to 7 inches. The most common residential building material used for walls is drywall, which has a nominal thickness of 4 inches. However, some states or regions may require thicker walls depending on the climatic conditions.
Therefore, it should be noted that the thickness of walls in constructed residential buildings is not the same.
What is the average thickness of a wall?
Building codes usually require walls to be at least 4 inches thick, which translates to an average wall thickness of 5 inches. The variation ranges from 3 inches to 5-1/2 inches depending on the local building codes and climatic conditions.

How thick are exterior and interior walls?
Exterior walls subjected to the weather often need to be 7-1/2 inches thick. This is necessary because they need to absorb the direct impact of heavy rain, hail, winds, and snow. Because of these adverse conditions, the insulation quality is reduced by almost half compared to interior walls. The standard thickness of interior walls is 4 inches, the same as drywall. The exterior wall is thinner than the interior walls because they don’t need to hold as much insulation.
What is the depth of an exterior wall?
The depth of a wall can also vary widely depending on your location and preference. However, when it comes to standard sizes, an 8-inch wall thickness is standard in both residential and commercial construction. Some homes are constructed with walls that are as thick as 12 inches, while some buildings use walls that are as thin as 2 inches.
How Wide Should a Cavity Wall Be?
When it comes to cavity wall construction, a wide cavity has several benefits. First of all, it allows for a cleaner design of the air/vapor barrier. Secondly, a wide cavity allows for a wider shelf/relieving angle, resulting in thicker structural steel. However, this can cause the thermal transfer. Hence, it is important to determine the correct width and thickness of a cavity wall before beginning construction.
To determine the right width for cavity walls, it is necessary to calculate the cavity area. The width of the wall should be approximately half the thickness of the external walls. The depth of the cavity should be half an inch below the top of the wall. The height of the wall must be at least two inches above the level of the ceiling.
When it comes to construction, most brick, block, and stone structures contain a cavity inside. While this gap can seem like an oversight, it serves an important purpose. It helps to maintain the temperature in the house. In addition to providing the required insulation, a cavity wall can reduce energy consumption.

A cavity wall comprises two separate walls joined together by metallic ties. The outer part is usually made of brick or structural clay tile, while the inner wall may be reinforced concrete, structural clay tile, or concrete blocks.
How Thick Should Plywood Be For Walls?
When choosing the thickness of plywood, consider the final product. Although manufacturers will try to get the thickness right, a piece of plywood can sag due to sanding or the moisture it absorbs from the surrounding environment. To avoid this problem, it is a good idea to measure the thickness of the board using calipers.
Plywood sheets are typically available in 4-foot-wide sheets. However, you can also find them in 8-, 10-, or 12-foot-long sheets. The longer sheets can be installed vertically on a wall, eliminating horizontal seams in the middle. This can improve water resistance and insulation.
The American Plywood Association (APA) recommends that sheathings be stapled to prevent the sheets from splitting. If you’re using nails, make sure they’re spaced at least 6 inches apart. In addition, double-tapping should be used. This will ensure that the sheets will not warp, and it will also increase the strength of the walls.
When selecting plywood, consider the project and the materials you’ll need. Depending on the size and nature of your project, you may need to select different types of plywood. If you’re unsure of the thickness of a particular type, you can use test cuts of the material to ensure it fits properly. If you’re working with small pieces of plywood, you can use a sawhorse with adjustable legs. Read about the related article here.
Conclusion
The thickness of walls in a residential home is not the same as the thickness of exterior walls. It’s important to know what is required by each state and country when working with contractors if you want to get the best results possible.
The average thickness of a wall is varied a lot, depending on the region of the country where you live. In areas where you expect extreme weather, such as hurricanes in the southeast and tornadoes in the midwest, walls are often made super thick and reinforced. Learn more about how the walls should be here.