Some Lake Norman homeowners winterize their own irrigation. Some hire a professional. Here's what the process actually requires — and where DIY approaches go wrong.
What Winterization Actually Involves
Irrigation winterization — specifically blow-out winterization, which is the appropriate method for Lake Norman's climate — requires forcing compressed air through each zone of the irrigation system to expel all water from the pipes, heads, and valves before freezing temperatures occur. Water left in the system expands when it freezes and cracks plastic pipe, fittings, and heads.
The Equipment Requirement
Blow-out winterization requires a compressor capable of delivering 20–50 CFM (cubic feet per minute) at moderate pressure for residential systems. The emphasis is on CFM — volume of air flow — not PSI (pressure). A standard shop compressor or portable home unit typically delivers 3–5 CFM, which is insufficient to move water through irrigation pipe. Using an undersized compressor at high pressure damages heads and valves without actually clearing water from the lines.
This is the most common DIY winterization problem: using an available compressor that delivers adequate pressure but inadequate volume, which results in water remaining in the system even though air was running through it.
Zone Sequencing
Each zone needs to be run separately with the compressor connected, until water has been expelled from all heads in that zone. Running the compressor too long on any zone (more than 2 minutes per cycle) can overheat plastic components. Multiple short cycles per zone are safer than one long run.
When DIY Is Reasonable
If you have access to a compressor that delivers 20+ CFM, understand the zone-by-zone process, and have a system without significant complexity (no backflow preventer that needs manual draining, no deep pipe runs that hold significant water volume), DIY winterization is feasible. For most residential Lake Norman systems, professional winterization costs $75–$150 — typically less than the cost of one cracked head replacement, and far less than a burst pipe repair in spring.
We offer irrigation winterization throughout Lake Norman — call 704-460-2019 in October or November to schedule before hard freeze season.
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