Garage firewall voided...

By a studor vent? What say you?

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If there is a void behind the vent, the firewall has been breached.


I think “fire resistant wall assembly” is the correct term.
Residential construction does not have any actual “firewalls”.

Even though that opening is wrong, it will not typically change the 1 or 2 hour rating all that much unless a gan of gas is burning right at it.

If it is a void then yes, but a easy fix would be replace the grill with a piece of dry wall marked of course with valve behind this cover.

Would this be allowed since the valves must be visible?

The CA Building Code simply refers to it as a “rated separation,” but I think most of us understand that it’s not really a “firewall.”

I disagree. This opening will significantly reduce the rating of the assembly (if only at that location) unless it has been appropriately sealed behind the register cover.

Fire rated access door.

The door to the house is allowed to be only a 20 minute door in most areas.

If it was marked Valve inside would it not be clearly visible ? or as James state fire rated Access. One thing i have seen here is pipes are extended and then sealed around . Still a simply repair.

This may be of help here for some.

Design Specification for Tudor Vent

I know this is kind of reitated material for some of us, but may help others.

**Fire ratings in attached garage. **

There is a common assumption that a wall with a certain fire rating will require a door with an equal rating. While the door will generally need to be rated it oftentimes requires a lower rating. These are the numbers from the 2006 International Building Code.

First, exterior walls always allow reduced ratings in doors. Both 3 hour walls and 2 hour walls require a 90 minute door. A 1 hour exterior wall requires a 45 minute door.

Where you have a fire barrier with a 1 hour rating at a shaft, exit enclosure or exit passageway you will need a 1 hour door. For other fire barriers it is reduced to a 45 minute door.

Where you have a fire barrier with required rating over 1 hour the need for reduction varies. Both a 4 hour wall and a 3 hour wall require a 3 hour door. Both a 2 hour wall and a 90 minute wall require a 90 minute door. In the 3 hour wall they will allow you to use a pair of 90 minute doors, but only in that once instance.

A 1 hour smoke barrier requires a 20 minute door.

Fire partitions that are corridor walls allow reductions. For either a 1 hour wall or a 30 minute wall you’ll need a 20 minute door. With any other fire partitions a 1 hour wall requires a 45 minute door and a 30 minute wall needs a 20 minute door.

The International Residential Code specifies how garages must be separated from dwelling units in residential construction. There are rules for openings (doors), for penetrations and for gypsum board in the wall assemblies.

First, you cannot have a door directly from a garage into a room used for sleeping. Where you are allowed to have doors leading from the garage into the dwelling unit the doors need to be solid wood a minimum of 1-3/8" thick, solid or honeycomb steel a minimum of 1-3/8" thick, or have a 20 minute rating.

Where you have ductwork running from the house through the garage it needs to be a minimum of 25 gage steel and there can’t be any openings into the garage. All penetrations through a rating need to be properly fire rated.

The garage needs to be separated from the unit by a minimum of 1/2" gypsum board applied to the inside of the garage and that goes to 5/8" gypsum board where the garage is below the rooms. You also need to protect any structure in the garage that is supporting the dwelling with 1/2" gypsum board.

Penetration - An opening created in a membrane or assembly to accommodate penetrating items for electrical, mechanical, environmental, and communication systems.
Through-penetration - An opening that passes through the entire separating assembly.

Hope this helps:):smiley: