STANDARD ON WATER SUPPLIES FOR SUBURBAN AND RURAL FIRE FIGHTING

WATER SUPPLY DETERMINING FACTORS EXTENT OF EVOLUTIONS SIZE OF and TYPE OF STRUCTURE CONTENTS METHOD OF ATTACK EXPOSURES RESERVES

NFPA 1403: 4.2 Structures and Facilities 4.2.23 The lead instructor shall determine the rate and duration of water flow necessary ..., including the water necessary for control and extinguishment of the training fire, the supply necessary for backup lines to protect personnel, and any water needed to protect exposures.

NFPA 1403: 4.2 Structures and Facilities 4.2.23.1 The minimum water supply and delivery for the live fire training evolutions shall meet the criteria identified in NFPA 1142, Standard on Water Supplies for Suburban and Rural Fire Fighting.

Definition: 4.1.5 (1) Exposure Hazard STRUCTURE WITHIN 50 FEET and 100 SQUARE FEET OR LARGER. (2) If class 3 or 4 OH, within 50 ft of another building, it is considered an exposure hazard regardless of size. What is an exposure really? (Anything that we don’t want to damage)

CLASSIFICATION OF OCCUPANCY HAZARD Chapter 5 CLASSIFICATION OF OCCUPANCY HAZARD WHAT OCCUPANCY TYPE IS THE MOST LIKELY TO BE USED IN LIVE FIRE TRAINING?

Occupancy Hazard Classification 7 5.2.5.1 Light hazard occupancy NFPA 1142 5.2.5 Occupancy Hazard Classification 7 5.2.5.1 Light hazard occupancy Dwellings

Classification Of Construction 6.2 .... structures shall be classified by type of construction and shall be assigned a construction classification number.

Dwellings Classification Of Construction 6.2.1 Type V (Wood Frame) Construction Classification Number 1.5 Dwellings

FOR ALL EXPOSURE HAZARDS MULTIPLY TOTAL BY: Chapter 4 Minimum Water Supply = (TOTAL CUBIC FT) x (CONST CLASS OCCUP 1.5) x ( Exp. Factor 1.5) (CLASS # 7) PER 1142 - FOR ALL EXPOSURE HAZARDS MULTIPLY TOTAL BY: 1.5

NFPA 1142 4.2 SINGLE STRUCTURES WITHOUT EXPOSURE HAZARDS (2000 gal. minimum) 4.3 SINGLE STRUCTURES WITH EXPOSURE HAZARDS (3000 gal. minimum)

NFPA 1403 50% Reserve SINGLE STRUCTURES WITHOUT EXPOSURE HAZARDS (3000 gal. minimum) SINGLE STRUCTURES WITH EXPOSURE HAZARDS (4500 gal. minimum)

Determining Minimum Water Supplies 4.6 The fire department shall develop the capability to deliver the amount of water determined in accordance with Sections 4.2 through 4.5 to the incident scene at the rate shown in Table 4.6.1

Total Water Required: Rate Capability: Table 4.6.1 Total Water Required: Rate Capability: < 2,500 2,500 - 9,999 10,000 - 19,999 > 20,000 250 500 750 1,000 Table put back in the 2007 edition Was an exception in 2002 (old 1231)

What if the exposure is larger than the structure being burned? Calculate water supply based on the larger structure

Multiple Exposures? NCFRC Exception Add .5 for each Exposure Example: 2 Exposures 1.5 1st Exposure + .5 2nd Exposure 2.0 Exposure Factor

3 Exposures = 1.5 + .5 + .5 = 2.5 (1) (2) (3) 4 Exposures = 1.5 + .5 + .5 + .5 = 3.0 (1) (2) (3) (4)

Determining Minimum Water Supplies Go back to NFPA 1403: 4.2.23.2 A minimum reserve of additional water in the amount of 50 percent of the fire flow demand in 4.2.23.1 shall be available to handle exposure protection or unforeseen situations.

Practice Time! See if your calculations are the same! (Remember – calculate gable roofs as ½ the height from the attic floor to the ridge pole)

50% additional reserve per NFPA 1403: 11,573 Total Gallons Exposure 50’ 50 x 24, 2 stories with gable roof, 8’ from attic floor to ridgepole 2 story w/gable roof 8’ ceilings 8’ to ridgepole 24’ 50 X 24 = 1,200 square ft. Height = 8 + 8 + 4* = 20’ 1,200 x 20 = 24,000 cubic ft. (Dwelling) Exp. OCCUP HAZ CLASS = 7 (divide by 7) 3429 GAL. CONST CLASS = 1.5 (multiply by 1.5) 5144 GAL. Go to Table 4.6.1 Table 4.6.1 shows: 500 GPM Must be capable of flowing 500 GPM for about 15 minutes. (7715 gal / 500GPM) 50% additional reserve per NFPA 1403: 11,573 Total Gallons 1 EXPOSURE HAZARD (multiply by 1.5) 7715 GAL. Exposure

65’ 1 story w/gable roof 8’ ceilings 8’ to ridgepole 30’ Dwelling Exp. 65’ x 30’ = 1,950 square ft Height = 8’ + 4* = 12 ft. 1,950 x 12’ = 23,400 cubic ft 1 story w/gable roof 8’ ceilings 8’ to ridgepole 30’ OCCUP HAZ CLASS = 7 (divide by 7) 3343 GAL. CONST CLASS = 1.5 (multiply by 1.5) 5014 GAL. Exp. Go to Table 4.6.1 750 GPM Flow for about 14 minutes (10,029 gal / 750 GPM) Dwelling 2 EXPOSURE HAZARDS (multiply 1 + .5 + .5) 10,029 Gallons 50% additional per NFPA 1403: 15,044 Total Gallons Exposures

52’ 44’ 2 story w/ mansard roof 10’ ceilings Dwelling 36,772 Gallons 52’ x 44’ = 2,288 square ft Height = 10’ + 10’ + 10* = 30’ 2,288 x 30’ = 68,640 cubic ft Exp. 52’ 44’ 2 story w/ mansard roof 10’ ceilings OCCUP HAZ CLASS = 7 (divide by 7) 9806 GAL. CONST CLASS = 1.5 (multiply by 1.5) 14,708 GAL. Exp. Exp. Dwelling Go to Table 4.6.1 1000 GPM Flow for about 37 minutes (36,772 gal / 1000 GPM) 3 EXPOSURE HAZARDS (1.5 + .5 + .5 = 2.5) 36,772 Gallons Exposures 50% additional per NFPA 1403: 55,158 Total Gallons

Remember! Calculate Square Footage Calculate Cubic Footage Occupancy Hazard Class Construction Class Exposure factor Required GPM Minutes Flow Sustained 1403 Reserve