Laying out spray heads on a 30 by 60 foot lawn strip.

Spacing: 15 ft on-center (head-to-head coverage).

• Run two rows down the 60-ft length, 15 ft from each long edge (15 ft apart).
• Heads every 15 ft along each row (5 heads per row = 10 heads total).
• This gives 100% overlap (radius = spacing).

Nozzles: 15-ft radius, matched-precipitation-rate (MPR) nozzles (e.g., Rain Bird 15-VAN, Hunter 15A, Toro 570-15).

• Use quarter-circle (90°) on four corners.
• Half-circle (180°) on eight perimeter heads.
• Full-circle (360°) if any interior heads (none needed here).

Pressure: Operate at 30 psi at the head (check nozzle chart; most 15-ft MPR nozzles deliver ~1.85 gpm @ 30 psi).

• Verify with a pitot gauge; adjust regulator or use pressure-compensating screens if >10% variation.

Layout check:

• 60 ft ÷ 15 ft = 4 intervals → 5 heads/row.
• 30 ft width ÷ 2 rows = 15 ft row spacing = head-to-head.
• All arcs sum to 360° per zone → matched precipitation.

Code/Standard: ASABE/ICC 802-2014 (landscape irrigation) requires head-to-head spacing ≤ radius; MPR nozzles for uniform application.

Pipe/Valve: 1-in. lateral (Class 200 PVC or poly) feeds 10 heads × 1.85 gpm ≈ 18.5 gpm. Use 1-in. valve; size mainline for ≤5 ft/s velocity.

Pro tip: Flag locations, run a catch-can test (tuna cans) after install; adjust arcs/pressure until CU ≥ 85%.

For a 30 ft × 60 ft lawn strip (1,800 sq ft), you’re likely dealing with a rectangular area best served by rotary or spray heads depending on water pressure and flow. Assuming standard residential irrigation (30–50 psi, 10–15 GPM available), here’s a practical, code-compliant layout:

Spacing & Nozzle Selection (Per Irrigation Association & Manufacturer Guidelines)

• Use 15-ft radius spray heads (common for strips): → Space heads 12–14 ft apart (80% of radius for head-to-head coverage, per IA best practices and most manufacturer specs like Hunter, Rain Bird, or Toro). → For a 30-ft width: Place 2 rows of heads, spaced 15 ft apart (centerline to centerline), running the 60-ft length. → Along the 60-ft length: Space heads every 14 ft → 60 ÷ 14 ≈ 4.3 → 5 heads per row (at 0’, 14’, 28’, 42’, 56’ — adjust ends to avoid overspray onto hardscape). → Total: 10 heads (2 rows × 5).

• Nozzles: → Use adjustable arc nozzles (e.g., Hunter MP Rotator, Rain Bird 5000 Series, or Toro Precision Series) set to:
• End heads: 90° arc (quarter circle) — spray inward only.
• Middle heads: 180° arc (half circle) — spray along the strip.
• Avoid full-circle nozzles on edges to prevent water waste on sidewalks/driveways. → Flow rate: Typically 0.5–1.5 GPM per head at 30 psi — check your zone’s GPM capacity to avoid overloading.

Critical Notes:

• Check pressure & flow: Measure static pressure and calculate GPM available (bucket test). If <10 GPM, consider drip irrigation or micro-sprays for efficiency.
• Avoid misting: If pressure >45 psi, use pressure-regulating heads or install a regulator.
• Overlap: Ensure 100% head-to-head coverage (no dry spots).
• Code: Follow local water conservation ordinances (many restrict spray heads in narrow strips; some require drip or bubblers).
• If unsure: Consult a licensed irrigator — improper design causes runoff, waste, or code violations.

Bottom line: 10 heads, 14 ft spacing, adjustable arc nozzles (90°/180°), pressure-regulated if >40 psi. Verify GPM and pressure first. (Sources: IA Technical Manual, Hunter/Spec Sheets, IPC Section 608.3)