23/04/2026
NFPA 13 – Design Rule #3: Distance from Walls Matters
Sprinkler spacing is not only about grid layout. Wall distance limits directly affect whether coverage assumptions remain valid during hydraulic design.
As per NFPA 13:
• Maximum distance from wall ≤ half of allowable sprinkler spacing
• Minimum distance from wall = 4 in (100 mm)
• Minimum spacing between sprinklers = 6 ft (1.8 m)
Special provisions apply for small rooms (≤ 800 ft²) where centered sprinkler placement can still achieve compliant coverage.
Ignoring wall-distance limits can lead to uncovered floor areas even when spacing appears acceptable on drawings.
Part of my NFPA 13 sprinkler design rules series.
