Fire and Safety Considerations

[muir]

In the fusing thread there was a rather dramatic picture of a trailer on fire. This timely posting coincided with my own thought process arriving at the issue of fire resistance and safety in general.

I've been looking at the plywood / foam / plywood sandwich construction technique, and one issue is that the foams used tend to be non-fire resistant, and the labeling indicates that in residential applications the foam should be protected by a non-combustible interior material.

Looking at the materials used to build these trailers, most of the stuff looks like fuel.

It seems like using exterior aluminum skin would help, as at least there is a barrier that reduces oxygen flow, and the skin isn't fuel in its own right.

I'm curious what techniques and strategies folks are using to make their trailers safe. Are there particular codes that one should try to meet?

I note that there are fire resistant paints that one could use on the interior, such as this one: http://www.firetect.com/wt102.htm
These products tend to be expensive, unfortunately.

I'd also like to hear what people feel are requirements for secondary egress, smoke/fire detectors, etc.

Thanks for any insights.

-Scott

[bdosborn]

I think I would start with the NFPA:

NFPA 1192
Standard on
Recreational Vehicles
2002 Edition
Chapter 6 Fire and Life Safety Provisions
6.1 Interior Finish and Textile or Film Materials.
6.1.1 Interior Finish Flame Spread Limitation. Interior finish (as defined in 3.3.17) of walls, partitions, ceilings, exterior passage doors, cabinets, habitable areas, hallways, and bath or toilet rooms, including shower/tub walls, of recreational vehicles shall be of materials with a flame spread classification that does not exceed 200 when tested in accordance with NFPA 255, Standard Method of Test of Surface Burning Characteristics of Building Materials. An alternate method of testing for cabinet door and drawer faces, exposed cabinet bottoms and end panels, and tub/shower walls shall be permitted to use ASTM E 162, Standard Test Method for Surface Flammability of Materials Using a Radiant Heat Energy Source, to establish the flame spread rating not to exceed 200.
Exception: The flame spread limitations of 6.1.1 shall not apply to moldings; trim; furnishings; windows, door, or skylight frames and casings; interior passage doors; countertops; cabinet rails; stiles; mullions; toe kicks; and padded cabinet ends.
6.1.2 Combustibility of Textile or Film Materials. Where the walls, partitions, or ceilings consist of textile or film materials, such as tent fabric, insect screening, flexible plastic weather protection, and so forth, they shall conform to the requirements of 49 CFR 571.302, paragraphs S4.3 and S5 of Federal Motor Vehicle Safety Standard No. 302, “Flammability of Interior Materials.”
6.1.3 Use of Cellular Foam or Foamed Plastic Materials. Cellular foam or foamed plastic materials shall not be used for interior finish (as defined in 3.3.17) in recreational vehicles.
Exception No. 1: Cellular or foamed plastic materials shall be permitted on the basis of fire tests that substantiate their combustibility characteristics, for the use intended, in actual fire conditions.
Exception No. 2: Incidental use of cellular or foamed materials for molding, trim, splash panels, and on doors shall be permitted.
6.1.4 Mirrors. All interior mirrors with an exposed area exceeding 431 in.2 (278,064 mm2) shall comply with ANSI Z97.1, Safety Glazing Materials Used in Buildings—Safety Performance Specifications and Methods of Test, or equal requirements and shall be so identified by the manufacturer of the mirror.
6.2 Recreational Vehicle Exit Facilities.
6.2.1* Minimum Exit Facilities. Recreational vehicles shall have a minimum of two exits located remote from each other and so arranged as to provide a means of unobstructed travel to the outside of the vehicle. Each bedroom or area designed for sleeping shall have at least two unobstructed paths to exit. The path to exit shall not require passing any designated exit to gain use of another designated exit except where any part of a bed in its normal sleeping configuration is within 24 in. (610 mm) of the plane of the nearest designated exit as projected across the vehicle. (See Figure A.6.2.1.)
6.2.2 Alternate Exits in Motor Homes and Truck Campers. The alternate exits in motor homes and truck campers shall be located on a wall other than that wall where the main vehicle exit door is located or shall be located in the roof. Use of the driver’s door as an alternate exit shall be permitted provided that the driver’s seat locks only in the forward position and arm rests, if any, are retractable and nonlockable when in the arm rest position. The distance between the upright portion of the seat in its extreme forward position and the nearest point of the steering wheel shall be not less than 12 in. (305 mm).
6.2.3 Access to Alternate Exits. The path leading to an alternate exit, other than that stated in 6.2.2, shall be not less than 13 in. (330 mm) wide at the narrowest point and as a minimum shall extend vertically from the supporting surface below the alternate exit to the top of the alternate exit. The supporting surface shall be not more than 3 ft (0.9 m) below the bottom of the alternate exit and shall be capable of supporting a weight of 300 lb (136 kg). Recreational vehicles that contain a designated roof alternate exit shall be provided with a ladder or equivalent device for descending from the roof.
6.2.4 Operation of Exits. The latch mechanism of any required exit facility shall be operable by hand and shall not require the use of a key or tool for operation from the inside. No more than 20 lb of force (89 N) shall be required to open a required exit.
6.2.5* Size of Alternate Exits. The alternate exit, if not an exterior passage door, shall provide an opening of sufficient size to permit unobstructed passage, keeping a major axis parallel to the plane of the opening and horizontal at all times, of an ellipsoid generated by rotating about its minor axis an ellipse having a major axis of 24 in. (610 mm) and a minor axis of 17 in. (432 mm). (See Figure A.6.2.5.) An exterior passage door if used for an alternate exit shall provide an unobstructed opening with a minimum horizontal dimension of 18 in. (457 mm) and a minimum vertical dimension of 48 in. (1.2 m).
6.2.6 Marking of Alternate Exits. Alternate exits other than exterior passage doors shall be identified by a waterproof label with the word “EXIT” in 1 in. (25.4 mm) minimum red letters on a contrasting background. The label shall be placed on the interior wall surface above or below the exit or on the interior ceiling surface, within 8 in. (203 mm) of the opening in an unobscured visible location or shall be installed on the interior of the exit frame or the movable portion of the exit approximately midway between the sides.
6.2.7 Identification of Alternate Exit Handles. Handles that must be operated to open alternate exits shall be colored red.
Exception: Exterior and interior passage door handles shall not need to be colored.
6.3 Fire Detection Equipment.
6.3.1 Smoke Alarms. At least one integral battery-operated smoke alarm shall be installed in each fifth wheel, travel trailer, truck camper, or motor home.
Exception: A fifth wheel or travel trailer that has only interior lighting capable of being powered only by a 120-V or 120-V/240-V external power supply shall be permitted to be equipped with a 120-V operated smoke alarm with battery backup that shall be on a branch circuit supplying lighting and receptacle outlets that shall not have ground-fault protection.
6.3.2* Smoke Alarm Listing Requirement. The smoke alarm shall be listed and marked on the device as being suitable for installation in recreational vehicles under the requirements of UL 217, Standard for Single and Multiple Station Smoke Alarms.
6.3.3 Installation of Smoke Alarm. The required smoke alarm shall be installed in accordance with its listing but not within the separate sleeping areas. The required smoke alarm shall be installed a minimum of 6 in. (152 mm) from all exterior walls measured edge to edge and away from the direct flow of air from heat and air-conditioning outlets.
6.3.4 Operational Check Warning Label. A permanent warning label with the word “WARNING” with minimum ¼ in. (6 mm) high letters and body text with minimum in. (3 mm) high letters on a contrasting background shall be affixed in a visible location on or within 24 in. (610 mm) of the smoke alarm and read as follows:
WARNING
TEST SMOKE ALARM OPERATION AFTER VEHICLE
HAS BEEN IN STORAGE, BEFORE EACH TRIP, AND
AT LEAST ONCE PER WEEK DURING USE.
FAILURE TO COMPLY MAY RESULT IN
SERIOUS INJURY.
6.4 Other Considerations.
6.4.1 Provisions for Portable Fire Extinguishers. Each motor home shall be equipped with a listed portable fire extinguisher with a minimum rating of 10-B:C. Each recreational vehicle equipped with fuel-burning equipment (other than the prime mover engine) or 120-/240-V electrical system shall be provided with a listed portable fire extinguisher with a minimum rating of 5-B:C as defined in NFPA 10, Standard for Portable Fire Extinguishers. The fire extinguisher shall be installed in accordance with its listing and Section 1.6 of NFPA 10 and shall be located within the recreational vehicle interior as near as practical to the primary means of exit.
Bruce

[muir]

Thanks Bruce, that is very informative.

I tried to follow up on your posting by researching the various standards, but I find they are almost all only available by purchase. The Federal Motor Vehicle Safety Standards can be found online, at least those parts referenced in NFPA 1192.

My further research on fire resistant paint coatings turns up several manufacturers of intumescent primers or paints. These seem to be the real thing - there are some "ceramic enhanced" paints which make claims about improved fire resistance, but they don't appear to have undergone the testing and approval that the intumescent products have.

The NFPA 1192 standard appears fairly relaxed about the flame spread rating of materials used in an RV. An FSR of 200 seems to allow for most of the materials folks are usually using. For a sample of ratings, see:
http://www.dps.state.la.us/sfm/planrevi ... atings.htm

I'm guessing one area to watch out for is the foams and fabrics used for cushions, etc.

Do you have any pointers to information regarding the codes that apply to the propane system on an RV (NFPA 58, perhaps)?

Thanks.

-Scott

[bdosborn]

I think that propane requirements are in chapter 3 of NFPA 1192. I'll post it tomorrow when I'm in the office, I didn't want to make my post to long. I think if your looking for a fire rating, you'll have to use steel studs and drywall to achieve any kind of meaningfull rating, not the best teardrop materials. I know there is a fire resistant paint that is used to give plywood telephone backboards a fire rating, but, its very expensive since I always get a phone call asking if its really needed. I guess I would question whether its better to use fire resistive construction or to invest in a good smoke detector. It seems like you could get out of the teardrop long before a fire posed a threat, assuming a smoke detector woke you up. I think fire resistive construction is used mainly for life safety, to give the occupants of a commercial or institutional type building time to exit the structure in an orderly fashion as opposed to trying to preserve the structure. But then again, I'm no architect (thank God)
Bruce

[muir]

I'm not really looking to build a trailer with a fire resistive rating, but I am trying to understand what is best, or at least common, practice.

I agree on the smoke detector as the first line of defense. I would certainly plan on that as well as propane and CO detectors, depending on the systems that were in the trailer.

I look forward to seeing what NFPA 1192 has to say about propane.

Thanks.

-Scott