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-   -   Do I have a Fire Rating Issues with Attached Garage (http://www.diychatroom.com/f19/do-i-have-fire-rating-issues-attached-garage-102724/)

Perry401 04-25-2011 09:20 PM

Do I have a Fire Rating Issues with Attached Garage
 
I am working on a house that has an attached garage. The ceiling over the garage is framed with joists 24" OC, with some sort of plaster board or cement board coated with 1/2 inch of plaster, apparently following building plans submitted to the city. The previous owner installed a huge, plywood door into the garage ceiling into the attic area above the garage, about 48 x 46 inches. This opens the garage area up for storage of equally huge items, such as canoes and large lawn furniture. This is a nice feature.

The walls on the main floor between the garage and adjacent living areas are 8 inch cinder block with 1/2 inch plaster applied directly on the gargage side. The living area side of these walls have 3/4 inch furring, some sort of mid-1940's drywall type boards, and finished with 1/2 inch plaster. The passage door between the garage and inside is a flat wood door. I have a copy of the approved building permit used to add the garage area. It indicates that this door was to be fire rated. The inspectional services never were called out for a final inspection -- only footer inspection, and I know of several places elsewhere in the house where the previous owner took short-cuts which were not to code.

Because of this, I do not know if the door is fire rated. The previous owner used the garage for storage and a workshop and never stored a car in it. He did keep the lawnmower, gasoline cans, solvents, etc. in the garage area, so I think he was only kidding himself if he thought the area did not need to follow aspects of the building codes.

In the attic area, there is no seperation between the attic above the garage and above and adjacent to second floor living areas. There are bedrooms on the second floor, along with attic access doors into the common attic area from these bedrooms.

I have a few questions:

1. Is the huge garage attic access door legal -- are their limits on size and/or does it need to be fire rated?
OR
2. Would it be better or necessary to install a fire-rated wall between the garage area attic and the living area attic? If I did this, could I keep the access door?
OR
2. Should I remove the garage attic access door altogether, using drywall and plaster to completely close the opening, and leaving access to the common attic only through the living space.

Concerning the pedestrian door into the garage -- How can I determine if the garage door is fire rated?

AndyGump 04-25-2011 10:54 PM

Look at the side of the door with the hinges, if it is fire-rated it will hve a red and white tag or some such tag stapled there.

As for the other issues it is a little difficult to determine what might be the best course of action without some kind of plan showing the details of the construction as is.

At least some pictures would be helpful.

Andy.

concretemasonry 04-25-2011 11:09 PM

The intent of a fire wall between a garage is a life safety issue to properly separate the garage from the living area with respect to allowing gasses, fumes and flame to spread and endange the inhabitants of the house.

Any opening in the wall (from garage floor to roof) violates the protection. This even applies to something like an small outlet to a large opening above the ceiling height since this is an easy opening to flame spread.

The man-door can be determined if it is adequate by a label on the jamb end of the door and may only require a new door to be hung. A large opening above the ceiling is a major destruction of the fire wall protection. The solutions were identified - close it up with a wall meeting the wall requirements or try to find a door that is appropriately labeled.

It is unfortunate that there was no local inspection done originally, since someone paid the cost included with the permit and the problems (except for DIY cheating) that future owners are faced with.

Dick

Perry401 04-26-2011 12:49 AM

There is no tag on the door -- I am familiar with these on steel doors, so I am assuming that the door is not fire rated. Changing the door should not be that big of a deal.

As far as plan drawings and/or photos, I do not have either in a format to share at this time -- I will try to explain verbally what I see as going on and what I see as inappropriate. If photos and/or drawings are still needed I will try to post them soon.

The house originally had a 2-bay attached garage. Part of the bay nearest the habitable part of the house was converted to use as a part of the kitchen in the late 1950's. This resulted in an "L" shaped garage. The garage door was changed to one car width and the space behind the extended kitchen was left with the original garage floor, etc.

Permit(s?) were pulled for this work, but as stated earlier, a final inspection was never done. Drawings for the permits consisted of a very crude plan view layout with written descriptions of walls, materials, etc. The permit athority returned a couple of sketchs of joist arrangement and other written notes. They required that the new walls surrounding the kitchen addition be constructed of cinder block, with a new footer placed below it through the existing concrete garage floor. So I am assuming that this wall is fire rated as high as it goes. I am assuming that at the time, the inspectional services did not see a need for the fire wall to extend above the height of the bottom of the attic flooring. However, nowhere in the plans is the large access door into the garage shown.

Prior to the building modifications, there was a cinder block wall that extended from the original footer/basement foundation all the way to the roofline. There was a door opening into the house through this wall. This wall was torn down in the area where the kitchen was expanded. New concrete block walls were installed as described above and extend to "about" the top of the floor joists above the kitchen, which are the same height as the "ceiling" joists in the garage area.

As the house was originally built, the garage area and the habitable part of the house were totally isolated from each other, with the exception of the pedestrian door. A fire in the garage would have to burn through the rafters and back down the other side of what I will call the "fire wall" between the house and the garage. Of course, fire could also penetrate the door between the garage and the house.

As I see it, today, the situation does not seem to be as stable. Firstly, the large access door from the garage into the attic provides little protection in it's current arrangement. A fire rated door might be better here, if one could be purchased, the use approved, etc.

Second, if a fire or fumes were to enter the attic area, there is no longer any seperation between the living portion of the house and the garage on the second floor level (where the attic is). A fire in the attic could spread horizontally to the second floor bedrooms and also burn downward from the attic to the first floor. Fumes or smoke in the attic could readily pass into the second floor bedroom area through the existing attic access doors.

I see houses all over the place with living areas over garages. I assume that these are relying on the drywall and/or plaster in the garage ceiling to provide an adequate fire barrier. I also see many houses with crawl-space access doors located in the garages -- but these are smaller openings -- barely big enough for a person to crawl through. Some access only the areas above the garages, but others access an attic which extends over the entire house.

While the ability to store large items in the garage attic is in some ways desireable, I am not opposed to closing the access door off entirely if this is needed to make things safe. It is probably the easiest fix if it would meet requirements.

I also could build a drywall on studs extension (or even extend the cinder block wall if structurally fesable) all the way up through the attic to the rafters to seperate the garage attic area from the attic areas above or adjacent to the habitable portions of the house. This however would require the existing roof rafters to penetrate the wall in some areas -- a fact that might make it harder to meet fire ratings. Of course the "fire wall" could be extended as described, and the roof rafters cut off so they don't go through the wall, but instead attach to it, but this would require a lot of thought and engineering to assure that the newly built wall could accept the load.

I hope this information further helps.

AndyGump 04-26-2011 12:58 AM

It is possible that you could create an envelope that is a fire barrier using 1/2" fire rated type 'X' GWB, taped and mudded of course, between the garage areas and the living areas on the vertical surfaces and 5/8" on the horizontal areas and this would suffice for code compliance.
Exactly how you would do that I don't know because I am not there or have a reasonably accurate plan to go by.
But it sounds like it could be done.

Andy.


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