GA Fire Sprinkler cheat sheet

Light hazard: occupancy where quantity/combustibility of contents is low (offices, churches, schools); design density typically 0.10 gpm/ft² over 1,500 ft² (check current NFPA 13 figures).

Ordinary hazard Group 1: 0.15 gpm/ft² over 1,500 ft²; Group 2: 0.20 gpm/ft² over 1,500 ft² (density/area curves in NFPA 13 Figure 19.3.3.1.1).

Extra hazard Group 1: 0.30 gpm/ft² over 2,500 ft²; Group 2: 0.40 gpm/ft² over 2,500 ft² (NFPA 13 Figure 19.3.3.1.2).

Wet-pipe system: automatic sprinklers attached to piping containing water under pressure at all times; most common and fastest-acting.

Dry-pipe system: piping under air pressure; water enters after a sprinkler operates and releases air; require dry-pipe valve, air compressor, and accelerator/exhauster for large systems.

Preaction system: dry piping with detection; single-interlock releases water on detection only; double-interlock requires both detection and sprinkler operation; non-interlock releases on either.

Deluge system: open sprinklers/nozzles; all discharge simultaneously upon activation of detection; used for high-hazard or special protection.

Design area may be reduced for quick-response sprinklers (up to 40% for wet systems per NFPA 13 19.3.3.2.3) and increased for dry systems (30% increase per 19.3.3.2.5) and sloped ceilings.

Occupancy classification drives density/area, sprinkler spacing, and water supply duration; mixed occupancies use the most demanding classification or separation per NFPA 13.

Maximum coverage area per sprinkler: light hazard 225 ft² (standard spray), ordinary hazard 130 ft², extra hazard 100 ft² (NFPA 13 Table 8.6.2.2.1(a)); residential sprinklers have separate limits.

Maximum spacing: light hazard 15 ft, ordinary hazard 15 ft, extra hazard 12 ft (standard spray upright/pendent); sidewall sprinklers have reduced limits (e.g., 14 ft light hazard).

Minimum spacing between sprinklers on same branch line: 6 ft (NFPA 13 8.6.2.2.1) to avoid cold soldering; closer spacing allowed with baffles or calculation.

Sprinklers must be within 12 in. of ceiling (deflector distance) for standard spray; 1-4 in. for residential; 1-12 in. for extended coverage per listing.

Obstruction rules: sprinklers must be located within 12 in. horizontally of obstructions ≤4 ft wide; greater than 4 ft wide requires sprinklers under or split; use NFPA 13 Figure 8.6.5.1.1.

Hydraulic calculation: density × area = minimum flow; use Hazen-Williams: p = 4.52 Q^1.85 / (C^1.85 d^4.87) in psi/ft; C=120 for black steel, 100 for galvanized (check NFPA 13 Table 27.2.4.1).

Balance point: the sprinkler with highest demand (hydraulically most remote) determines required supply; add hose allowance (e.g., 250 gpm for light hazard) to supply demand.

Safety factor: NFPA 13 requires no specific safety margin, but many designers add 5-10 psi or 10% to account for uncertainties; verify with local requirements.

Pipe sizing: use schedule 40 steel for 1-in. and smaller; schedule 10 for 1¼-in. and larger; NFPA 13 allows listed CPVC, PEX, copper, and steel with specific listings.

NFPA 13D: one- and two-family dwellings and manufactured homes; design for 10-minute water supply duration; at least one sprinkler in each compartment; no attic/crawlspace sprinklers generally.

NFPA 13D requires a minimum of two sprinklers in the most demanding area; flow typically 10-20 gpm at 7 psi residual for listed residential sprinklers.

NFPA 13R: residential occupancies up to and including four stories above grade (e.g., apartments, condos); design for 30-minute duration; requires sprinklers in all habitable areas, closets, and some attics per 13R.

NFPA 13R design density: 0.05 gpm/ft² over the entire floor area (or 0.10 gpm/ft² over most remote 2 sprinklers, whichever greater); check current edition.

Residential sprinklers (NFPA 13R/13D) have lower design pressures (7 psi) and larger coverage (up to 20 ft x 20 ft for 13D) than standard spray.

NFPA 13R permits omitting sprinklers in small closets (<24 ft²), bathrooms (<55 ft²), and certain attics/crawlspaces if noncombustible or limited combustible.

NFPA 13D systems may be connected to domestic water supply; must have a bypass for maintenance; no fire department connection required.

Both 13R and 13D require a water flow test or approved source; 13D allows a storage tank with pump or pressure tank; 13R usually requires a dedicated water supply.

Weekly/monthly: inspect gauges (monthly), control valves (weekly/monthly), and alarm devices (quarterly for waterflow).

Annual: main drain flow test, waterflow alarm test, valve operation test, dry-pipe valve trip test, fire pump flow test (annual), and antifreeze solution test.

5-year: internal inspection of piping and sprinklers (or representative sample) for dry systems; gauge replacement or calibration every 5 years.

Sprinkler replacement: quick-response sprinklers at 20 years, then 10-year intervals; standard response at 50 years, then 10-year intervals (NFPA 25 Table 5.4.1.1.1).

Main drain test: record static and residual pressure; compare to baseline; a drop of >10% indicates a supply problem or valve partially closed.

Dry-pipe valve trip test: annual; record time to trip and time for water to reach test valve; should be within 60 seconds for dry pipe (NFPA 25).

Fire pump annual flow test: test at 0%, 100%, 150% of rated flow; compare to baseline; churn pressure should not exceed 140% of rated.

Impairment procedures: tag system, notify fire department and occupants, provide fire watch if system out of service >4 hours (NFPA 25 Chapter 15).

Water flow test: measure static pressure, residual pressure, and flow; plot on semi-log paper; extrapolate to 0 psi to estimate available flow (N^1.85 graph).

N^1.85 formula: Q_r = Q_s × ((P_s - P_r)/(P_s - 0))^0.54? Actually use: Q_available at 20 psi = Q_flow × ((P_static - 20)/(P_static - P_residual))^0.54 (Hazen-Williams exponent 1.85).

Fire pump sizing: rated flow must not be less than system demand; rated pressure must meet demand plus safety margin; churn pressure ≤140% of rated.

Fire pump types: centrifugal (most common), vertical turbine, positive displacement; drivers: electric motor or diesel engine; diesel requires fuel supply for 1-hour (or per NFPA 20).

Standpipe classes: Class I (2½-in. outlets for fire department, 100 psi at top), Class II (1½-in. for occupant use, 100 psi), Class III (both).

Standpipe design: wet standpipes in heated buildings; dry standpipes in unheated; manual standpipes require fire department connection; automatic requires water supply.

Fire department connection (FDC): required for all automatic sprinkler systems except 13D; must be accessible and marked; check valve and drain required.

Water supply duration: light hazard 30 min, ordinary hazard 60-90 min, extra hazard 90-120 min (NFPA 13 Table 19.3.3.1.2); 13R 30 min, 13D 10 min.

Georgia requires a state fire sprinkler contractor license issued by the Georgia Fire Marshal's Office (Office of Insurance and Safety Fire Commissioner) under O.C.G.A. Title 25-12.

License categories: Fire Sprinkler Contractor (company) and Fire Sprinkler Technician (individual); contractors must employ at least one certified technician.

Qualifications: minimum 2 years documented experience in fire sprinkler installation for technician; pass NICET Level II or state exam; background check and fingerprinting.

Continuing education: technicians must complete 8 hours annually (or per rule) including code updates and safety.

Insurance: general liability ($500,000 minimum per occurrence) and workers' compensation required for licensure.

License renewal: biennial (every 2 years) with fee; expired license requires reinstatement and late fees.

Contractors must provide a certificate of liability insurance and list of employees; changes must be reported within 30 days.

Unlicensed practice is a misdemeanor; penalties include fines and cease-and-desist orders.

Georgia adopts the International Fire Code (IFC) and International Building Code (IBC) with amendments; NFPA 13, 13R, 13D, and 25 are referenced standards.

State Fire Marshal adopts codes; local jurisdictions may enforce with amendments; check local amendments (e.g., City of Atlanta, Fulton County).

Plan review: submit shop drawings, hydraulic calculations, and manufacturer's product data to the local authority having jurisdiction (AHJ) for approval before installation.

Permit required before installation, alteration, or repair of sprinkler systems; fees based on system size and occupancy.

Inspections: rough-in inspection after piping installed before concealment; final inspection after system complete and tested; hydrostatic test at 200 psi for 2 hours (or 50 psi above working pressure).

As-built drawings and hydraulic calculations must be provided to owner and AHJ after completion; NFPA 13 requires contractor to provide these.

Georgia requires a Certificate of Occupancy before building use; sprinkler system must be operational and inspected.

Appeals of AHJ decisions go to local board of appeals or state fire marshal; time limits apply.

Personal protective equipment (PPE): hard hat, safety glasses, gloves, steel-toe boots, and hearing protection when using pipe cutters or threading machines.

Fall protection required when working at heights >6 ft (OSHA 1926.501); use ladders, scaffolds, or lifts properly; inspect before use.

Lockout/tagout (LOTO) procedures required when servicing or maintaining equipment with hazardous energy; follow OSHA 1910.147.

Pipe cutting and threading: use proper tools; keep hands clear; support pipe securely; thread cutting oil required for steel pipe.

Soldering copper: use lead-free solder; ventilate area; fire watch required when soldering near combustibles; keep fire extinguisher nearby.

Pressure testing safety: never exceed test pressure; use calibrated gauges; barricade area; do not stand in line with test caps.

Housekeeping: keep work area clean; store materials properly; avoid trip hazards; dispose of debris daily.

Excavation safety: call 811 before digging; use trench boxes or sloping for trenches >5 ft deep; competent person required.