Quick answer: In Ontario, spring is for checking winter damage and drainage, summer is for cooling, ventilation and exterior materials, fall is for gutters, heating equipment and shutting down exterior water lines, and winter is for ice damming, condensation and alarm checks. Add a walkthrough after any severe storm. Most expensive home repairs start as a maintenance item that got skipped for two or three seasons.
Ontario runs a house through four different climates a year. Ice, thaw, heat, humidity, and then back again.
Most of what goes wrong is predictable. A gutter fills, water overflows at the same corner every storm, the soil there erodes, the grading reverses, and three years later the basement takes water in a heavy spring rain. Every step of that was visible and cheap to fix. The last one is neither.
Here is what to look at, and when.
Spring: check what winter did
Spring is the audit. You are looking for damage that happened while you were not outside much, and for the water that comes with the thaw.
Outside
- Walk the perimeter and look at grading. Soil settles over winter, and a slope that once fell away from the house can reverse.
- Check that every downspout still has its extension and discharges well away from the foundation, onto a permeable surface where possible.
- Clear gutters of the debris that came down late in the fall, and look for sagging sections and separated joints.
- Look up at the roof from the ground. Missing tabs, lifted shingles, granules collected at the bottom of the downspout, and damaged flashing all show up now.
- Check masonry for spalled brick and failed mortar, which is what freeze and thaw does over time.
- Inspect decks, stairs, railings, and guards. Push on them. Winter loosens things.
Inside
- Go through the basement or crawl space carefully. Damp corners, staining, efflorescence, or a musty smell after a thaw all mean water found a way in.
- Check window wells for standing water and debris.
- Test the sump pump by pouring a bucket of water into the pit. If it does not start, you want to know in April, not during the first summer storm.
- Turn on the exterior hose bibs after the freezing risk has passed, and then go check the wall inside for leaks. A split frost free bib often only shows itself when you open the valve.
Summer: cooling, ventilation, and exterior materials
Summer is when the cooling and ventilation systems earn their keep, and when it is comfortable enough to do exterior work.
- Replace or clean HVAC filters on the manufacturer's schedule. This is the highest value five minute task in the house.
- Clear vegetation, fencing, and debris from around the outdoor condenser or heat pump. It needs airflow on all sides.
- Run the air conditioning before you need it. Weak cooling, short cycling, or unusual noise is a call to a licensed HVAC contractor in June, not during a heat warning in July.
- Check that bathroom fans and the range hood actually move air. Hold a piece of tissue up to the grille. If it does not hold, the fan is not doing anything for your humidity.
- Confirm the dryer vents outside and clean the duct. Lint restriction is both a moisture issue and a fire issue.
- Inspect and reseal exterior caulking at windows, doors, and penetrations.
- Look at decks and balconies structurally, not cosmetically. Check the ledger connection to the house, fastener corrosion, and any rot at posts where they meet concrete.
- If the property has a pool, well, or septic system, book the appropriate seasonal service. These are not items to defer.
Fall: get ahead of winter
Fall maintenance is the highest return work of the year, because everything you skip now gets tested in January.
- Clean gutters after the leaves are down, not while they are still falling. Then check that water actually flows through and out.
- Review the roof from the ground or another safe vantage point. If it is steep, high, or otherwise unsafe to access, a drone roof inspection is the sensible option. Trim back any branches touching the roof surface.
- Have the heating system serviced by a licensed contractor before the first cold snap. Book early, since availability disappears in November.
- Replace the furnace filter and check that supply and return vents are not blocked by furniture, rugs, or storage.
- Shut off and drain exterior water lines, and disconnect hoses. A hose left attached is a common cause of a burst pipe inside the wall.
- Check weatherstripping and door sweeps. Air leakage costs comfort and drives winter condensation.
- If the home has a wood-burning fireplace, stove, or insert, this is the time for chimney service and, where applicable, a WETT inspection. Some insurers require WETT documentation for wood-burning appliances, so check your policy before you need to.
Winter: ice, condensation, and safety
Winter reveals things no other season will.
- Watch for ice damming at the eaves, oversized icicles, and uneven snow melt on the roof. Those patterns point at heat loss into the attic and inadequate ventilation.
- Look for condensation on windows and cold exterior walls, especially in bedrooms and closets on north facing walls. Persistent condensation means indoor humidity is too high for those surfaces.
- Keep snow clear of exhaust terminations, fresh air intakes, gas meters, dryer vents, and basement windows. A blocked high efficiency furnace vent is a genuine safety issue.
- Check alarms. Smoke alarms are required on every storey and outside all sleeping areas. And as of 1 January 2026, under Ontario Fire Code amendments in O. Reg. 87/25, homes with a fuel-burning appliance, a fireplace, or an attached garage need a carbon monoxide alarm adjacent to each sleeping area and on every storey, including storeys without bedrooms. Test monthly and replace units on the manufacturer's schedule. Details are in the TSSA summary.
- Do not close off unused rooms completely. Cutting heat and airflow to a room raises the risk of frozen pipes in an exterior wall and creates a cold surface for condensation.
After severe weather
Storms have become the reason for a lot of unplanned repairs in this region. A short walkthrough afterward is worth doing every time.
Check the basement first, then the attic, then the roof edge and exterior walls, then drainage paths and the sump pit. Look for new staining, water entry, lifted or missing exterior materials, and any new odour.
Landlords and property managers should log weather related complaints with dates and photos. Commercial and investment property owners should also treat roof and drainage performance as a budget line, since deferred roof maintenance shows up later as tenant issues and interior damage.
Keep the records
Maintenance records are worth real money at three moments: when you sell, when you make an insurance inquiry, and when you are trying to work out whether a problem is new.
Keep invoices for HVAC service, roofing, waterproofing, and electrical work. Keep permits and any Electrical Safety Authority documentation. Keep photos of anything you are monitoring, dated, from the same angle each time. Keep past inspection reports.
Buyers ask for this. Insurers ask for this. And when a stain reappears in the same corner three winters later, you will want to know exactly what was done the first time.
When a maintenance inspection makes sense
A home maintenance inspection is worth booking when the house is older and has not been reviewed in years, when you are planning renovations and want to know what should be corrected first, when you have noticed comfort or moisture problems you cannot pin down, or when you own rental or commercial property and need a prioritised list rather than an opinion.
It is also useful after a purchase, when the original inspection flagged items to monitor. Monitoring only works if someone actually goes back and looks.
The point is not to make every small thing sound urgent. It is to sort what needs doing now from what can be planned for next year, and from what just needs watching.
Frequently asked questions
How often should an Ontario home be professionally inspected?
There is no rule. A practical approach is a professional maintenance inspection every three to five years for an average home, more often for older properties, rentals, or any building where problems have already appeared.
What is the single most important seasonal task?
Managing water at the exterior. Clean gutters, extended downspouts, and positive grading prevent more expensive damage than anything else on this list.
When should I have the furnace serviced?
Early fall, before the heating season starts. Booking in September or early October usually gets better availability than waiting for the first cold week.
Do I need a WETT inspection for my fireplace?
It is not required by law for every homeowner, but many insurers require WETT documentation for wood-burning appliances, and it is commonly requested during a real estate transaction. Check your policy wording.
Are carbon monoxide alarms required on every floor in Ontario?
As of 1 January 2026, yes, for homes with a fuel-burning appliance, a fireplace, or an attached garage. Alarms are required adjacent to each sleeping area and on every storey, including storeys without bedrooms.
