The Myth of fire-rated walls and doors between the house and garage.

Home Inspector with Charles Buell Inspections Inc.

A common mistake that home inspectors make when inspecting single family residences is related to opinions stated about the separation between the home and the attached garage.  There comments often leave them "out on a limb" when repairs are called for.

Out on a limbI routinely hear erroneous statements about compromised “fire-rated surfaces” between the house and the garage.  Statements declaring that the surfaces between the house and the garage are not “1hr fire-rated,” or that the “1hr fire-rated surfaces” are in some way compromised,are very common in inspection reports.  The door or doors placed in this “separation” are also frequently misunderstood and incorrectly reported on.

The wall between the house and the garage---believe it or not---is NOT a fire-rated assembly and is referred to in the code as the “Garage/Home Separation.” 

Requirements to meet this “separation” requirement are really quite minimal compared to what would be necessary in an actual “fire-rated assembly”  (As would be required between multiple dwelling units like condos, townhouses and duplexes.) 

Typically ½” drywall is all that is necessary to meet the separation requirement.  If there is living space above the garage, the ceiling would have to be 5/8” type “X” drywall.  Again, this is not a “fire-rated assembly,” but merely what is required to meet the proper “separation” requirements.

Regarding the door between the house and the garage, all that is necessary is to install a door that meets the “separation requirements.”  There is nothing that says it has to be a “fire-rated door,” as frequently reported by home inspectors.  While this may seem confusing, if one looks at the code it becomes clear.  It also reveals the source of some of the confusion.

To meet separation requirements, the door must be one of three types of doors:  1. Solid wood door not less than 1-3/8 inches thick, 2.  Solid or honeycomb core steel doors not less than 1-3/8 inches thick, or 3.  A 20-minute fire-rated door.

The first two types are fairly self explanatory but the inclusion of the third type has lead to a great deal of confusion because a door that is a “20-minute fire-rated door” leads one to think that the doors in general, and thus the walls, have to somehow be “fire-rated.”  For a door to achieve a 20-minute fire-rating it has to go through testing procedures by Underwriters Laboratories and then it receives its “UL listing” as a fire-rated assembly.  One of the things that are required to meet the requirements to be listed as a 20-minute fire-rated assembly is for it to have a self-closure mechanism.  Since door types “1” and “2” do not “require” closure devices it is little wonder that some inspectors conclude that none of the doors require them----even though the type “3” door requires one in order to meets its UL listing.  Because the words “self-closure” do not appear in the code, some builders and home inspectors (and even jurisdictional inspectors) mistakenly take this to mean that no closers are required on any type of door between the house and the garage.

Since manufacturer’s requirements supersede code, it is a little disingenuous to conclude that code does not require them.

Required weather-stripping on these doors is covered in other parts of the code both for energy conservation and as a barrier to fumes and combustion by-products.

Hopefully this post will help clear up some of the confusion.


Charles Buell, Seattle Home Inspector


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Jay Markanich
Jay Markanich Real Estate Inspections, LLC - Bristow, VA
Home Inspector - servicing all Northern Virginia

I often hear the 5/8" drywall referred to as "fire block," which, of course, it really isn't. 

But is it anything like a splash block?

I'm surprised Kierkegaard didn't get on that one.  It's profound to contemplate...

Mar 22, 2011 08:33 AM #12
Charles Buell
Charles Buell Inspections Inc. - Seattle, WA
Seattle Home Inspector

Steve, yes---I think that is more accurate

Nutsy, glad to see you are your normal confused self

Jay, about as useful as a splash block

Mar 22, 2011 11:40 AM #13
James Quarello
JRV Home Inspection Services, LLC - Wallingford, CT
Connecticut Home Inspector

Like Steve I have changed the language in my report template to fire separation wall. Perhaps resistant would be better still.

With regard to CT I am not aware of of a requirement for a 1 hour fire rated door. It could be a requirement in some towns, but none that I know of. The 5/8 sheet rock is usually put in the ceiling only, not the walls.

Mar 22, 2011 09:05 PM #14
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Great post.  I never knew the 20-minute fire door thing required a self-closer.

Mar 22, 2011 09:34 PM #15
Steven L. Smith
King of the House Home Inspection, Inc - Bellingham, WA
Bellingham WA Home Inspector


I have this code book, put out by the code council, that explains all the stuff in human terms. Good book and it refers to it all as fire-resistance and I grabbed it when Nutsy and I realized how confused Mr Charles was by all of that, up until now.

Mar 22, 2011 11:39 PM #16
Pam Jank
Coldwell Banker Schneidmiller Realty - Coeur d'Alene, ID
Your Coeur d'Alene & North Idaho Real Estate Pro

Charles, Thanks for more great useful information and setting thigs straight ......

Mar 23, 2011 12:25 AM #17
Dale Ganfield
Leland, NC

Hi Charles, very informative.  I agree this is often a point of confusion from both sides of the inspection report.  Thanks

Mar 23, 2011 07:47 AM #18
Charles Buell
Charles Buell Inspections Inc. - Seattle, WA
Seattle Home Inspector

Jim, the requirements of a one hour fire rated door likely wouldn't be very attractive in a home :)

Reuben, thanks

Steve--a great resource you have there

Pam, you are welcome

Dale, I can't tell you how many times I hear people talk about "1hr fire-rated" in terms of the house/garage separation

Mar 23, 2011 09:59 AM #19
Stephen Stanczyk
Safe Haven Home Inspections - Puyallup, WA
Home Inspector - Puyallup WA

Pierce County allows 1/2" C or X rated drywall if the studs are 16"OC.    If they are greater than 16" OC, 5/8 X or C is required.


I just went through this on a new construction phase.  HVAC techs installed regular 1/2" on the walls and ceiling around the gas furnace and main duct.  They didn't much care when I called them on it.  The AHJ just happened to be on site so I asked what the county was requiring.  Then he went to 6 other homes under construction with the same company hvac trucks parked in front.  Oops.....

Mar 23, 2011 11:55 PM #20
Charles Buell
Charles Buell Inspections Inc. - Seattle, WA
Seattle Home Inspector

Stephen, so are you saying that Pierce County has amended the code to make the code more strict?  Interesting.

Mar 24, 2011 12:47 PM #21
Don Agel Owner Agel's Home Inspections Fayetteville NC

A 20 minute window of time before the fire/smoke can breach through the walls/doors/ceilings that separate the attached garage from the living space and consuming the house and occupants is nothing to try to belittle and do a code play on wording. The whole design of the separation is to give you 20 minutes rather than 3. Place an interior door in the entry opening between living space and garage and you not only allow for the infiltration of toxic fumes from exhaust and stored fuels/chemicals but you breach the 20 minute window. Even an improperly installed fire rated entry door unit can allow for a decrease to the time. The comments that the solid wood or metal door units are not fire rated is not exact as they have also been tested to determine the amount of time taken before they become compromised and were found to be comparable to the 20 minute fire rated units on the mass market today. Sorry that the written word in the code book doesn't play to all intellectual levels such as many directions on prepared food packaging. I am angered that people would try to dumb up the general public on the importance of this separation. Can you fully wake up in a smoke filling house with flames breaching through an improper separation and not only wake your family but try to escape in three to five minutes? Most homes have no smoke-heat detection installed in the garage. 20 minutes not only gives you a "chance" at a safe egress but allows time for emergency officials to arrive and try to save whats left. Human life is more important than trying to save some money during construction and argue about code wording when you are missing the big picture as to why there is a separation requirement. JFYI, non-rigid/unsealed ducting not allowed in garage, all penetrations to be sealed with fire retardant sealants, no non-fire rated attic access allowed in the ceiling of the garage that does not meet 20 minute minimum rating, and no ceiling accesses installed in the garage if a room for sleeping is directly above. I pray that the ignorance that some of you are spreading hasn't already caused the lives of loved ones that could have been spared!


Dec 31, 2011 11:39 AM #22
George Mitchell

Do not ever assume that the door you bought is a fire rated doors. Always look for the label and if it was not there conduct some testing.

Jul 24, 2013 06:04 PM #23
Matt weber

It's Underwriters Laboratories not United...


Aug 22, 2013 03:19 PM #24

As a general rule, the building standards in place at the time a residential building was approved under and built is the correct building standard for construction that a building need to be maintained to. Just because a new version of a building or residential code comes out, that doesn't necessarily mean all existing homes need to comply is the newer code requirement.

The correct answer is to apply the version of the code the building was approved under for the required construction standard for a particular building that's use (occupancy) or configuration is not changing and not necessarily the newest or current codes. Of course, is there are specific retroactive building standard required by law, then the it would be appropriate to apply those current building standards then.

Aug 22, 2014 04:52 PM #25

My parents purchased a 1 acre lot with an existing shop with an apartment upstairs. My mom has Alzheimer's so they want to add a bedroom and bathroom down in the garage area. They are also adding an elevator to assist with getting my mom upstairs. They are using 5/8 inch drywall and fire rated doors for the elevator door and the door into the downstairs bedroom. There is also a large window in the downstairs bedroom as a means of egress. King Co planning told us that we would have to add a hallway from the bedroom to the exterior so you wouldn't have to go through the garage to access the bedroom. Is this correct?

Oct 14, 2014 01:49 PM #26
Charles Buell
Charles Buell Inspections Inc. - Seattle, WA
Seattle Home Inspector
Hi Heather, among other requirements a bedroom cannot have access from the garage, and perhaps that is what the hallway is all about.
Oct 14, 2014 02:11 PM #27

Question, I had an inspection done on my home in NC and I am missing my "Fire Rated" Label on my service door between my Garage and Living area. How might I prove to the inspector that it is in fact a fire rated door? I remember there being a label of some sort there at one point but now it no longer exists. Any help would be appreciated.

Nov 06, 2014 12:12 PM #28

Depending on the building code standard that your home was built under, the door between the house and garage doesn't necessarily need to be fire rated. A rated door or a 1 3/8" solid core wood door that self closes and latches would have been acceptable.

For instance, assuming your house was built recently use International Residential Code as the basis for building standards, you want to look under Section R302.5.1

It will read something close to this (this one has California Amendment language added to it):

R302.5.1 Opening protection. Openings from a private
garage directly into a room used for sleeping purposes
shall not be permitted. Other openings between the garage
and residence shall be equipped with solid wood doors not
less than 1 3 / 8 inches (35 mm) in thickness, solid or honey-
comb-core steel doors not less than 1 3 / 8 inches (35 mm)
thick, or 20-minute fire-rated doors, equipped with self-
closing and self-latching devices.

Exception: Where the residence and the private garage
are protected by an automatic residential fire sprinkler
system in accordance with Sections R309.6 and R313,
other door openings between the private garage and
the residence need only be self-closing and self-latch-
ing. This exception shall not apply to rooms used for
sleeping purposes.

Nov 06, 2014 12:36 PM #29
Larry Wolf

Can a garage entry door be a double door?

Apr 08, 2015 04:32 PM #30
Charles Buell
Charles Buell Inspections Inc. - Seattle, WA
Seattle Home Inspector

Larry, I do not see why it could not be as long as it meets the requirements for house garage separation.  I suppose both segments would have to be self closing.

Apr 09, 2015 04:35 PM #31
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