Getting a Roof Ready for Ontario's Spring Storm and Hail Season
Spring is when winter damage surfaces and convective weather arrives. A methodical walk-around in March and April finds the small problems while they are still small.
Spring is the busiest diagnostic season of the year for a roofer, for two reasons that arrive at once. The first is that everything winter did to a house becomes visible when the snow finally goes. The second is that Southern Ontario's convective weather season starts ramping up in late spring — squall lines, downbursts, heavy rain and hail — and it arrives on whatever condition the roof happens to be in. A couple of hours in March or April is the cheapest maintenance you will ever do.
What Spring Weather in This Province Actually Throws at a Roof
Spring is a transition between two very different air masses, and that contrast is what drives severe weather. Warm, humid air moving up from the south meets cold air still in place to the north, and the boundary between them is where storms organize. In practice that means fast-moving lines of thunderstorms, straight-line wind from downbursts that can do as much damage as a weak tornado, very heavy rain falling on ground that is still saturated or partly frozen, and hail. It also means large day-to-night temperature swings that keep working every joint on the building, and the last few freeze-thaw cycles of the season landing on materials already fatigued by winter.
The Walk-Around: Start From the Ground
Most of a useful spring inspection is done from the lawn with a pair of binoculars, which is both safer and more informative than people expect. Walk the whole perimeter and look up at every elevation, then walk it again looking at the bottom two metres of the building.
- ✓Roof surface: on shingles, look for lifted or missing tabs, dark patches where granules have washed off, and any course that looks out of line. On metal, look for panels that have shifted, seams that look open, dented or distorted trim, and fasteners that stand proud on exposed-fastener systems.
- ✓Ridge and hips: caps and closures are the first thing wind finds. Check that the ridge line is straight and that nothing has lifted.
- ✓Eaves: look for damage from ice, and for eavestrough that has been pushed out of alignment or pulled away from the fascia by ice or sliding snow.
- ✓Flashings: chimney, wall intersections, skylights, plumbing stacks and vents. Look for lifted metal, failed sealant and any counter-flashing that has come out of its reglet.
- ✓Soffit and fascia: panels that have come out of their channel, staining that suggests water has been running where it should not, and any sign of animal entry, which is very common in late winter.
- ✓Siding: check the lowest courses for impact and salt damage, and check that trim, corners and the starter strip are all still fully engaged.
- ✓Fences and gates: look for posts that have heaved, panels that have racked, and gates that no longer close square.
- ✓The ground itself: granules washed out of the downspout outlet, pieces of trim in the garden, and where the water from your downspouts is going now that the ground has thawed.
Eavestroughs First
Clearing rainware is the highest-value spring task on almost every house. Over the winter troughs collect leaves that blew in after the fall cleaning, grit and granules washed off the roof, and shingle debris from ice movement. A blocked trough backs water up under the roof edge, overflows against the fascia and soffit, and dumps concentrated water against the foundation exactly when the ground is saturated and least able to take it. While you are up there, check that downspouts run free, that the hangers are still holding the trough at the right slope, that seams and end caps have not been opened by ice, and that discharge is carried well away from the foundation rather than emptying beside it.
Hail: What It Does to Different Surfaces
Hail does not damage every roof the same way, and knowing the difference matters for deciding what to do next. On an asphalt shingle, a hailstone impact bruises the mat — it fractures the reinforcing beneath the surface and knocks granules loose. The bruise may not leak that day or that year, but the granule layer is the shingle's ultraviolet shield, and once it is gone from a spot, the asphalt beneath ages far faster. Hail damage on shingles is progressive: it starts a clock. On a metal panel, a hailstone that strikes hard enough leaves a dent. A dent in a panel is a deformation of a continuous sheet, not a breach of a protective layer. Flat, broad pans dent more visibly than profiles with striations, ribs or stiffening beads, which is one of the practical reasons those features exist. Softer metals such as aluminum and copper deform more readily than steel of the same thickness.
Cosmetic Damage Versus Functional Damage
This is the distinction to hold onto after a storm. Functional damage means the roof's ability to keep water out has been reduced: a fractured shingle mat, a torn or displaced panel, a split seam, a punctured surface, damaged flashing, or a fastener that has been driven through. Cosmetic damage means the roof still performs but does not look the way it did: dimpling in a flat pan, minor dents in trim, scuffing. Both are worth documenting; only one is urgent. On soft-metal elements such as aluminum eavestrough and some trims, visible denting after a hail event is common while the roof panels themselves are unaffected. Have someone competent look at it rather than deciding from the driveway, and be cautious about anyone who knocks on the door after a storm and tells you the roof is finished.
Photograph the roof, the elevations, the trim and the fences every spring while everything is in good order. A dated set of before photographs is the most useful thing you can have when you later need to show what a storm did, and it takes ten minutes.
Wind Preparation, Briefly
The wind-related items on a spring list are all about the edges. Confirm that ridge caps, rake and gable trim, drip edge and any counter-flashing are still tight and mechanically held rather than relying on old sealant. Check that soffit panels are fully seated, because a blown-out soffit lets wind pressurize the attic. On exposed-fastener roofs, look for screws that have backed out or gaskets that have deteriorated, since each one is both a potential leak and a loose point in the fastening pattern. Finally, deal with overhanging limbs and any dead wood within falling distance of the house, because spring wind will find it.
Frequently Asked Questions
Should I get up on the roof myself in the spring?
Preferably not, and particularly not on a metal roof, which is slippery, easy to damage with the wrong footwear and unforgiving of a slip. Almost everything on a homeowner's spring list can be checked from the ground with binoculars or from a properly footed ladder at the eave. Anything that needs a closer look is worth a call.
How do I know whether hail actually damaged my roof?
Look at the softer, more obvious targets first: aluminum eavestrough and downspouts, vents, flashings, air conditioner fins, and painted metal trim. If those are marked, the roof took the same impacts. On shingles, look for scattered dark spots where granules have been knocked loose. On metal, look for dents and for any distortion at seams and panel edges. Then have it assessed by someone who does not benefit from the answer being yes.
Do dents in a metal roof need to be repaired?
It depends entirely on whether the panel and its coating are intact. A shallow dent in the middle of a pan with an undamaged finish is a cosmetic matter. A dent that has creased a seam, distorted a panel's engagement with its clips, or broken the coating is a different situation and should be looked at. The judgment is about performance, not appearance.
What is the single most important spring job?
Clearing the eavestroughs and confirming the downspouts discharge well away from the house. More spring water damage in Southern Ontario comes from water that was not carried away from the building than from anything that happened on the roof itself.
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