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Attic Access Requirements | 5 Things You Should Know

Lets get straight to the point.

The attic access requirements for residential structures can be found in Section R807.1 of the 2018 International Residential Code.

Due to the likelihood of requiring access to the attic space for repairs and maintenance during the life of a home, the code establishes the minimum requirements for attic access to ensure it is functional and safe.

In addition to this, it is a convenient way for fire department personnel to gain entry into a concealed space, such as an attic, and address any potential fire hazards.

Therefore let us cover the 5 main things you should know when it comes to attic access openings per the International Residential Code.

1. Attic Access Requirements

When is an Attic Access Required?

Section R807.1 requires buildings with combustible ceiling or roof construction to have an attic access opening to the attic areas that have a vertical height of 30 inches or greater over an area of no less than 30 square feet.

Attic Access Area
Illustration: © Building Code Trainer, 2021

It is important to note here that the vertical height is measured from the top of the ceiling joist to the underside of the roof rafter.

2. Attic Access Location

Where should the Attic Access Opening be Located?

The opening for the attic access must be located in a hallway or other area that has readily accessible.

This can be either in the ceiling or in a wall that opens into the attic area.

3. Attic Access Size

What is the Minimum Size of an Attic Access?

The code requires the rough framed opening of the attic access to be not less than 22 inches by 30 inches.

When located in a wall, the width must not be less than 22 inches and the height not less than 30 inches.

Attic Access Size
Illustration: © Building Code Trainer, 2021

When located in a ceiling, a minimum unobstructed headroom clearance must be provided.

4. Attic Access Head Clearance

What Clearance is Required Above an Attic Access Opening?

The code requires the minimum unobstructed headroom in the attic to not be less than 30 inches above the access. This is measured vertically from the bottom of the ceiling joist.

Attic Access Clearance
Illustration: © Building Code Trainer, 2021

5. Mechanical Equipment in Attic Area

What is the Attic Access Requirement when Mechanical Equipment in located in the attic?

To understand what the attic access requirement is for mechanical equipment located in the attic, the code directs us to the mechanical code section found in the residential code.

Section M1305.1.2 specifies the clearances required to access the appliance located in an attic for maintenance how a key take away from this section related to the opening itself is to make sure it is large enough to allow for the removal of the largest appliance.

This is to account for the fact that an appliance might need to be replaced over time therefore if one is provided in the attic area, the attic access opening serving this space must be large enough to remove the old appliance.

So this sums up the basic code requirements for attic access openings.

For more information regarding detailed requirements, be sure to check out Section R807 of the 2018 International Residential Code (IRC).


Reference Source – 2018 International Residential Code – [Buy on Amazon]

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