How do I properly winterize an irrigation system before NB's freeze?

Winterizing your irrigation system in New Brunswick is absolutely essential and should be completed by late October — before the ground begins to freeze — to prevent the catastrophic pipe and fitting damage that frozen water causes in NB's -25°C to -35°C winter temperatures. Unlike milder regions where winterization is optional, failing to properly winterize in New Brunswick will almost certainly result in cracked pipes, split fittings, and broken backflow preventers that cost hundreds or thousands of dollars to repair in spring.

The standard winterization method in NB is a compressed air blowout, which forces all remaining water out of the system using an air compressor. You need a compressor capable of delivering 50-80 PSI at a minimum volume of 10 CFM (cubic feet per minute) for rotor systems, or 80 PSI at 20+ CFM for larger systems with multiple zones. Do not exceed 80 PSI, as higher pressure can damage PVC pipes, poly pipe connections, and sprinkler head mechanisms. Most homeowner-grade compressors are too small — you will likely need to rent a commercial compressor ($50-80 per day) or hire a professional.

The blowout process follows a specific sequence. First, shut off the main water supply to the irrigation system. Open the drain valve (if equipped) to release standing water from the main line. Connect the air compressor to the blowout fitting — this should be a permanent fitting installed on your system's main line, typically near the backflow preventer. Start with the zone farthest from the compressor and work inward, blowing each zone for 2-3 minutes or until no more water is visible from any head in that zone. Run each zone through the blowout cycle twice to ensure all water is expelled from low spots and fittings.

After the blowout, take these additional NB-specific steps. Remove and store any above-ground backflow preventers indoors for the winter — these contain rubber seals and brass components that are expensive to replace if frozen ($200-500 for a new backflow preventer installed). Insulate any above-ground pipe sections or valve boxes with foam insulation covers. Leave the controller powered on but set to the "off" or "rain" position to maintain programming — NB power outages during winter storms can erase schedules if the backup battery dies.

Most NB irrigation professionals charge $75-150 for a complete winterization service, which includes the compressor, blowout of all zones, draining the backflow preventer, and a visual inspection of the system. Given the potential cost of freeze damage (easily $500-2,000+ for burst pipes and cracked components), professional winterization is one of the best maintenance investments you can make. Book your appointment in early October, as NB irrigation companies fill their winterization schedules quickly and late October availability can be limited. If you are in a northern NB location like Bathurst or Campbellton (Zone 3b), aim to complete winterization by mid-October as freezing arrives earlier.

---

Find a Landscaping Contractor

New Brunswick Landscaping connects you with experienced contractors through the https://newbrunswickconstructionnetwork.com:

• Urban Landscaping Ltd ✓
• Hickory Dickory Decks Moncton ✓
• Leger Steel Roofing ✓