What is the code for exterior wall thickness?

Author: Ramona Wintheiser  |  Last update: Tuesday, October 21, 2025

The minimum thickness of exterior walls in one-story buildings shall be 10 inches (254 mm). The walls shall be laterally supported at intervals not exceeding 24 feet (7315 mm). The minimum thickness of interior load-bearing walls shall be 8 inches (203 mm).

How thick do exterior walls have to be?

Standard ICF external walls need six inches of concrete. However, areas susceptible to high winds require concrete thickness of at least 8 inches. The engineering tables review several characteristics of the building's design and location when establishing the concrete core size and the rebar layout.

What is the minimum thickness of outer wall?

For residential purposes the external walls requirement as per Building bye-laws is 200mm block work or 230mm brick work or 150mm RCC wall. All internal walls can be 100mm in block work or 115mm brick work.

How thick should exterior wall sheathing be?

9 and this section on all sheathable exterior wall surfaces, including areas above and below openings. Structural sheathing panels shall consist of minimum 7/16-inch-thick (11 mm) oriented strand board or 15/32-inch-thick (12 mm) plywood.

What is the minimum wall thickness?

The minimum nominal thickness of flat walls shall be 4 inches (102 mm) ...

A lesson about Wall Sheathing in Residential Construction - TEACH Construction Trades Training

How many inches thick is a standard wall?

Typical interior walls are framed with 2x4s. This makes walls about 4½ inches thick (3½ inches of wood covered on both sides by ½-inch-thick drywall). Read on to learn all about types of walls, must-know tips for window and door openings, and measurements for typical wall materials.

Is 7/16 OSB good for exterior walls?

Wall Impact Resistance - Ensure that all exterior walls are constructed using a wall system that provides, at a minimum, the resistance to wind pressures and debris impact provided by 7/16-in. -thick OSB wood structural panels attached to wood wall framing.

What is the most common exterior wall sheathing?

Five common structural exterior sheathing options include wood-based, gypsum, glass mat, cement board, and Barricade® Thermo-Brace®. Plywood sheathing is made from whole sheets of wood that are cross-laminated, which give the boards strength and stiffness.

How thick is a modern external wall?

A solid brick wall is usually about 22 cm thick, a cavity wall between 27 cm and 30 cm thick, and a solid stone wall could be as much as 50 cm. The age of your home can also be a good indicator. As a general rule, if it was built before the late 1920s it is unlikely to have a cavity.

Is there a code for masonry structures?

IS 1905: Code of Practice for Structural use of Unreinforced Masonry.

What is the minimum wall thickness for a load-bearing wall?

1) Minimum thickness of load bearing RCC wall should be 100 mm. 2) If the story height is equal to length of RCC wall, the percentage increase in strength is 10. ∴ If the storey height is equal to length of RCC wall, the percentage increases in strength is 10.

Should exterior walls be 2x4 or 2x6?

While 2×6 walls are more structurally sound, they are rarely needed. 2×4 construction is strong and structurally sound, especially when working with a custom home builder that uses premium materials.

What is the thickness of a commercial exterior wall?

6 to 12 Inches (Exterior Walls)

Exterior walls typically range from 6 to 12 inches in thickness and play a crucial role in a building's thermal envelope. Thicker exterior walls are beneficial because they allow for the use of denser insulation materials that provide higher R-values.

What is the standard drywall thickness for exterior walls?

Drywall (when installed) should be the same size on all walls in the house. 1/2” drywall is the standard. If it is on an addition that separates two homes, the one wall joining them should be fire rated 5/8”.

Should I use plywood or OSB for exterior walls?

That, in a nutshell, is the one big advantage plywood holds over OSB. The greater ability a wall has to dry, the more durable it will be, and everyone agrees that more moisture will pass through plywood.

Which is stronger, 3/4 plywood or 3/4 OSB?

Strength. OSB and plywood are very similar in terms of strength, but plywood is stiffer than OSB by a factor of approximately 10%.

How long will an OSB board last outside?

The service life of OSB is indefinite (expect 50 years or longer) if it is used and protected properly. 2. OSB should not be used where it is permanently exposed to the outdoor environment unless panels are qualified as Exterior (e.g. siding) and recommended coating is periodically renewed.

Are exterior walls 16 or 24?

Research has shown exterior framed walls can be adequately supported by 2x6 studs spaced 24-inches on-center. This wider spacing reduces the number of studs in the wall, thus reducing thermal resistance and increase the amount of space available for insulation.

What is the sheathing is applied to exterior walls?

Exterior sheathing is a board or panel made from various materials, installed over the exterior walls of a building. Its primary functions include lending structural stability and insulating the home. Let's dive into the layers that make up your home's exterior.

Are 2x6 exterior walls code?

2 x 4 framing is generally code compliant. Here at Medeek Design we typically only specify 2 x 4 studs @ 16" o.c. spacing, for small sheds and garages with a building widths less than 16 feet. All other larger structures are generally called out with 2 x 6 exterior studs @ 16" o.c. unless specified otherwise.

How thick are residential exterior walls?

Generally, exterior walls in residential buildings range from 4 to 12 inches, depending on the materials used and the climate. For example, traditional wood frame walls typically have a thickness of 6 inches, while masonry walls can be thicker, often reaching up to 12 inches or more.

What is the bottom 2x4 of a wall called?

The bottom plate is the lower horizontal framing member of a stud wall.

Do studs run vertically or horizontally?

Stud boards run vertically through the walls, from the ceilings to the floors. Inside your house, they're covered in drywall or plaster, so they aren't immediately visible. You might wonder, "How far apart are studs?" These framing boards are usually spaced 16 inches or 24 inches apart during construction.

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