Hi all,
I am planning on placing a basement under an existing home and have run into a few road blocks. I have reviewed the threads on adding basements which have been quite useful. But this question is related to fire code. I’ll provide a little background in order to provide the reader with some pertinent info.
The house (cabin) is 512 sq ft (16 ft x 32 ft). The existing cabin walls are 3 in. milled logs (1964 cedar log kit). There is no wall cavity in the existing cabin, just 3 in. of solid wood. Therefore all plumbing or electric either runs under the existing floor or on the wall surface.
The new basement will be within the original footprint. The new basement will most likely be completed using ICFs. The new basement will be completely open, trusses will span the 16 ft wide space. I will have some partition walls for a closet and bathroom.
The water supply for the community is a spring fed system with a pretty low rate of flow (10 gpm). The community water system has two 10,000 gal storage tanks. The water system only runs 6 months of the year (spring through fall). I have installed 5,000 gal of winter water storage on my property (buried poly tanks).
I have been told by the Fire Marshall that the hydrants in the community do not meet fire code (they are 3 in. hydrants). Because the hydrants do not meet code, I was first notified that I would have to install automatic sprinklers. However, since the new construction is within the original footprint, and the cabin is small, I have permission from the Fire Marshall to use area separation (1 hr burn between the new basement and the existing cabin above) as an equivalency as long as the Building Official will sign off on using area separation.
The building official has suggested to solutions:
1) have a flow test completed on the water system, if the system can provide 1,000 gpm, then there isn’t any issue with sprinklers or area separation (1,000 gpm is based on the fire code requirment of flow for residential structures 0-3,600 sq ft in size)
I have reservations with this solution because the water system only contains water 6 months out of the year, the two 10,000 gal storage tanks are empty in the winter, and a fire truck would never reach the site in the winter anyway (Utah winter, up to 300″ of snowfall each year at site), and after all the fuss I would likely be back at the Fire Marshall’s desk explaining that system may flow 1,000 gpm, but only 6 months out of the year. Then I would be back at the starting point (sprinklers). Plus, I would like to have permit in hand by spring and waiting to complete a flow test until spring (when the water system is running again) would likely push the project into next year.
2) if area separation is used, I will have to find a way to not penetrate the drywall between the basement and the existing upper level or use collars around all penetrations.
Wiring and plumbing will need to be routed from the basement to the existing upper level and neccesitates penetration. Does anyone have any creative ideas on how to handle this situation? I will be digging into the code books shortly, but wanted to post this in order to get some feedback from experienced individuals like yourself before I start searching the books. If you require additional information or more background, send me your questions and I will clarify.
Thanks,
Rob
Replies
If you go to http://www.UsG.com they list appropraite fire rated assemblies. they are really no that difficult and usually involve just a second layer of type-x gyp board. at every penetration, a fire rated caulk is needed. Hilti has the most used system for caulking. A 1-hour rating is the least restrictive, you should not have any trouble or much expense.
I personally would avoid a domestic fire system at all costs. It would probably need a backflow preventer and a yearly test and certification.
Dave
Where do you live, or more specifically, what code governs the work? How close to your property lines is the structure? Are there local ordinances more restrictive than the state building code?
Pending that information, I doubt the code will require either a fire separation or a sprinkler system, regardless of hydrant size/ flow rates. There are plenty of houses in this country working off a well, with no hydrants in the vicinity. They don't typically have sprinkler systems.
I would contact the local bldg materials supplier that may sell firestopping materials. Talk to them and ask for they're fireproofing guru. This person shou;d be able to explain code in laymans terms and offer solutions to your predicament.
My experience tells me that 4PCF rock wool batting and fire caulk (3M) should get you approved by the inspector/fire marshal. If not, he knows something I don't.
Best Regards
The fire ceilings I have seen detailed are all surface mounted. So all the piping, wiring, everthing goes direcly below the fire wall/dry wall. Then, a second ceiling is "hung" from the first, with nipples for the sprinkers. This way there is no perforations into the fire wall.Regards,
Boris"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
I agree. The FD made "suggestions". It sounds like there is no practical possibility to satisfy their "suggestions". I doubt if they can justify stopping or requiring you to comply with their suggestions.Then there is the dry sprinkler system. The system is dry until activated, then operates out of a reservoir. Usually just long enough for the FD's calculated response up time. Then they will either hook into and service your system with their pumper or fight the fire with their equipment.With or without, sounds like you only have a 50/50 chance, at best of being successful. However, on the bright side, the possibility of an internally started fire is miniscule.Never serious, but always right.
Sounds to me like a one hour rated ceiling assembly, possibly required to extend a few inches out from under the existing structure to slow flames climbing up the exterior, and some care in treating the penetrations needed to get services into the structure above would take care of this.
No big deal.
As I remember it, be sure to check this, two layers of 5/8" X-rated rock hung on RC-1 channels will get you to 1 hour rating. Piece of cake on a small structure.
The penetrations will be slightly more complicated but not overly so. Mostly drilling slightly oversized holes for the runs and filling with sufficient intumescent caulk or putty to take up any space created by any insulation or pipes melting or shifting.
Larger penetrations may need a sheetmetal shield designed to hold greater quantities of putty in place. You can buy purpose built units for these jobs, probably easier but not cheaper for larger holes, or assemble what you need. As penetrations get larger inspectors tend to like to see the bought units.
Rob, unless you're planning on having a separate living suite in the new basement - i.e. tenants downstairs - I'm wondering why you would need either level of fire protection. Single family houses do not require fire protection between the basement and the upstairs.
If your cabin is located in a forested area, I'd spend my time figuring out how to minimize the risk of the cabin going up during a forest fire...
Hi All,
Thanks for the info. I've got to check into some of the details/approaches and additional issues mentioned in the responses, but it all sounds doable. Thanks for the assistance, and of course, if anyone else wants to throw in their ideas, I'll keep reading.
Thanks,
Rob