Garage floor same level as house a safety concern?

I inspected a single story house with an attached garage built in 1961 in OH. I have a question about a saftey concern with the fuel vapors traveling into the basement. See photo attachment. At the door from garage to the house is a stair landing. The main house is 3 risers up and the basement is 10 or so risers down. Also, the wall between the house and garage was constructed of wood studs and painted fiberboard. This is what I reported: *Although this house was likely built according to code there is a present issue that the owner should be aware of. The issue is that the garage floor is at the same level as the house and there is a potential for gasoline vapors traveling down into the basement should they become present in the garage. As a minimum the owner should ensure the weather-stripping and sweep is very tight fitting and will prevent vapors from traveling into house. Additional considerations would be the addition of taped drywall and a 20 minute fire door that leads into the house. See excerpt from National Assoc. of Certified Home Inspectors. *Did I report this correctly? And at what point do you think there is not a problem with the difference in height between the garage and the main house floor? I assume the garage floor needs to be 18" below the main floor to be considered safe.


I wouldn’t be very concerned about the garage and the main level being very close to the same height. The pic looks like there is a weather strip type threshold in place, I believe the 18" rule would be more applicable to ignition sources like water heaters. In my area almost all slab homes have a similar transition from the garage to the home with only 1 or 2 inches difference between the garage floor and the main floor.

hello Terry
I don’t know where you are from. But what i see in the pic is a door to the house that is a wooden door and a screen door that is in front of it. I don’t know of a level that needs to be as far as fumes entering the house. I have never heard of that and inspected many slab homes that were none or little height difference. But if the basement is a living area the door does not appear to be fire rated and the screen door to the same area does not meet fire safety because of the glass. If there is a fire rated door to the house living area to the left than that area is ok.

The 18 inches is for gas fired water heaters or furnaces. It is wise to have a 2-3 inch step from the garage to the house to prevent water intrusion.

Some of my concern is that within about 8’ of the bottom of the basement steps is a NG furnace and NG HW tank. And a finished space is just adjacent to bottom of stair as well. [The house is in Ohio] Go Bucks!

Thanks for the input!


I would be concerned that the door was not a rated fire door and had no spring hinge.

The door looks like it is a solid wood door so I would think that would contain a fire long enough. If it was hollow core then it should be changed out.

AS for being level, I always recommend weather stripping and a self closing devise on the main door due to carbon monoxide from cars that are idling in the garage. This poison is heaver than air which will settle at the floor of the garage and can be pulled into the home several ways.

Always carry a steel ball to check that the floor slopes to the vehicle door.:slight_smile:

When I find issues with the garage door into the home it’s usually a lack of a fire rated door and no spring hinges or spring hinges are not adjusted to close the door. Many times during the construction of the home the tradesman relieve the spring tension on the door hinges to prevent damage to the door and it doesn’t get reset.

garage floor can be at same level according to most codes, it does need to slope though towards the outside.


I have found many municipalities do not require that the attached garage door self-close (go figure). Has that been your experience, also?

I quote national fire safety requirements.

shouldnt the storm door hing on the same side as the entrance door?