Closing a cottage for winter comes down to one priority above all others: getting every drop of water out of the plumbing before the first hard freeze. Everything else on the list, the cleaning, the furniture, the photographs for your insurer, matters too, but a pipe that splits in January is what turns a quiet off-season into an expensive spring.
In most of the country the window for this work runs from mid-September to Thanksgiving weekend, and the reason is simple. Once overnight temperatures start dipping below freezing at an unheated building, water sitting in a supply line, a trap or a hot water tank expands and finds the weakest joint. Cottage owners often lose a season to a slow leak that ran undetected for months, which is also why insurers treat seasonal properties differently from a primary residence. Policies on vacant or seasonal homes commonly require the owner to do one of three things over winter: drain the plumbing and shut off the water entirely, keep the heat above a stated minimum temperature, or arrange for someone to physically inspect the property at set intervals, often every three to seven days. Those conditions are not boilerplate. If a claim comes in and the condition was not met, the claim can be denied.
The other thing worth saying plainly before you start: a few of the jobs on a typical cottage closing list are not do-it-yourself jobs. Inspecting or repairing a roof, cleaning eavestroughs from a ladder, checking a chimney, and anything involving a propane line, a gas appliance or an electrical panel all belong to a licensed professional. The savings are not worth a fall from a ladder or a gas leak in a building nobody will visit for five months.
Step 1: Read your insurance policy before you touch anything
Find the vacancy or seasonal-occupancy clause and read what your insurer actually requires. Confirm the minimum temperature if you plan to leave heat on, the required inspection interval if you plan to leave water on, and whether you need to notify the company that the property is closed. Doing this first tells you which of the two paths below you are taking.
Step 2: Walk the property and photograph everything
Do a full circuit outside and a room-by-room pass inside, and take dated photos as you go. Note the condition of the roofline, foundation, windows, dock and outbuildings. If you spot damage to the roof, chimney or eavestroughs, book a contractor rather than climbing up yourself. The photo record does two jobs: it documents the condition you left the place in, which matters if you do file a claim, and it speeds up opening day next spring.
Step 3: Shut off the water at its source
Close the main shut-off valve. If you draw from a lake or well, shut down the pump, disconnect it and bring the foot valve and intake line inside or store them per the manufacturer’s instructions. Cut power to the pump at the breaker so it cannot run dry.
Step 4: Open every tap and drain the system by gravity
Open every faucet in the building, hot and cold, indoors and out, and leave them open for the winter so pressure cannot build in the lines. Open the lowest drain point in the system and let gravity pull the water out. Drain the pressure tank as well.
Step 5: Drain the hot water tank
Shut off power (or the fuel supply) to the tank first, then attach a garden hose to the drain valve at the base and run it outside or to a floor drain. Do not skip the power step. An electric element that fires in an empty tank will burn out.
Step 6: Clear what gravity leaves behind
Low spots and horizontal runs hold water even after draining, so finish the job one of two ways. The first is compressed air: connect a compressor to the system and blow the lines out fixture by fixture until only air comes through. Keep the pressure low. RV manufacturers, whose plumbing systems are winterized the same way, advise roughly 30 psi and warn against exceeding about 40 psi, because higher pressure can damage fittings and fixtures. The second option is non-toxic plumbing or RV antifreeze, the pink propylene glycol product sold for potable systems. Never substitute automotive antifreeze, which is poisonous and is not rated for drinking water lines. Many owners do both, blowing the lines out and then adding antifreeze to the traps.
Step 7: Deal with toilets, traps and water-using appliances
Flush each toilet and hold the flapper open until the tank empties, then sponge out what remains in the tank and bowl. Pour non-toxic antifreeze into every drain trap, including sinks, tubs, showers and floor drains, so the water sitting in the P-trap cannot freeze and crack it. Drain the dishwasher and washing machine, disconnect their supply lines, and add antifreeze to their pumps if the manufacturer calls for it.
Step 8: Have a licensed technician handle propane and fuel appliances
Shutting down, disconnecting or recommissioning propane tanks, furnaces, fireplaces, water heaters and ranges is work for a licensed gas fitter or HVAC technician. Book it rather than doing it yourself. You can safely clean the barbecue and store it under cover, but leave the tank disconnection and storage to the person who knows the code requirements in your province.
Step 9: Empty the fridge, freezer and pantry
Clear out all food, including anything in cupboards, and take it home or throw it out. Clean the fridge and freezer, then unplug them and prop the doors open so they do not grow mould over the winter. Seal any remaining dry goods in hard containers with tight lids. Mice will find a cardboard box.
Step 10: Set the heat or shut the power down deliberately
If you drained the system, you can shut the main breaker off, leaving only circuits you need for a security system or a monitored temperature sensor. If you are leaving water in the building instead, set the thermostat to the minimum your policy requires (commonly somewhere between 10 C and 15 C) and confirm someone will be checking on it. A wifi-connected temperature and water sensor is a worthwhile addition either way, as long as you also leave the internet connection running.
Step 11: Store gear and secure the building
Bring in patio furniture, cushions, barbecues, tools, kayaks and anything else that will blow around or fill with water. Pull the dock if your shoreline requires it. Close and lock all windows and doors, draw the blinds, and remove or hide anything valuable that is visible from outside. Leave a laminated copy of your closing checklist near the main shut-off so next year’s version of you knows exactly what was done.
Done properly, closing a cottage is a half-day job for most buildings, and the plumbing portion is the part that repays the care. Work through it in order, resist the urge to rush the draining, and hand off the roof, gas and electrical items to the people licensed to do them.
Sources: Ratehub.ca cottage winterization checklist; Sonnet Insurance; CAA-Quebec, Closing the cottage; Home Hardware closing guide; Keystone RV, winterizing plumbing with compressed air; Keystone RV, winterizing with non-toxic antifreeze.
