Key Things to Know About Sprinkler System Winterization
In Canada, winterizing your sprinkler system isn’t just a maintenance “suggestion”—it is a survival necessity for your plumbing. Given the deep frost line in most Canadian provinces, water left in underground pipes will expand as it freezes, leading to shattered PVC, cracked valves, and a very expensive repair bill in the spring.
Finding the Golden Window for Your Region
In Canada, the goal is to have your system shut down before the first hard frost. While the ground takes time to freeze deep down, the vulnerable parts (backflow preventers and copper pipes coming out of your house) can freeze during the first overnight dip below 0°C.
- The Prairies (AB, SK, MB)
Aim for mid-to-late September. Alberta is notorious for “September surprises” where temperatures can plummet overnight.
- BC Coast (Vancouver / Victoria)
You have more breathing room, often into early November, but don’t skip it—coastal freezes can still crack exposed backflow devices.
- Ontario and Quebec
Aim for early-to-mid October. Canadian Thanksgiving is the traditional “final deadline” for most homeowners in the GTA and Montreal.
At Water Your World, we service the GTA and surrounds, and our winterization services are scheduled starting on 1st October.
Critical Components to Protect
It’s not just about the pipes. Certain parts of your system are more delicate than others:
- The Backflow Preventer
This is usually the most expensive part of your system. Because it is often located above ground or near the surface, it is the first thing to burst.
- Main Shut-off Valve
This is typically inside your basement or crawlspace. You must ensure the water is turned off here, and the “bleeder” cap is opened to drain the small amount of water between the indoor valve and the outdoor line.
- The Controller (Timer)
Most modern controllers can simply be turned to the “Off” or “Rain Delay” setting. This keeps your programming saved for next year without trying to activate valves in the winter.
Professional vs. DIY - Why Understanding Your Winterization Needs is Essential
Many Canadian homeowners own a small air compressor for filling tires or using nail guns. These are usually insufficient for winterization.
The secret to a safe blow-out isn’t high pounds per square inch, or PSI, which deals with pressure; it’s high cubic feet per minute, or CFM, which is about volume.
The Danger
If you use a small compressor, you might have high pressure but not enough “wind” to push the water out. The air will simply bubble over the water, leaving a puddle at the bottom of the pipe that will freeze and crack it.
The Pro Advantage
Professionals use “tow-behind” industrial compressors that provide high CFM at a safe, low PSI (usually 50–80 PSI). This creates a “wall of air” that clears the line without melting the plastic gears inside your sprinkler heads.
Quick Checklist for Homeowners
- Locate your indoor shut-off and turn it off before the first frost.
- Open the “test cocks” on your outdoor backflow preventer to release pressure.
- Book your winterization early. Canadian irrigation maintenance companies get backlogged quickly in October.
- Insulate any exposed copper. Use foam “pool noodle” style insulation for any pipes visible above ground.
Opting For Professional Winterization
For certainty and safety when shutting down your sprinkler system for winter, it is strongly recommended to schedule services with a professional irrigation company.
For fall shutdown and winterization in the Greater Toronto Area, you may book with Water Your World at +1 – 905 – 689 – 6168.
We serve the areas of Brantford, Toronto, Oakville, Niagara, Mississauga, Burlington, Hamilton, Flamboro, Guelph and other surrounding areas.
