Storing a Trailer Outside for an Ontario Winter: Roof Checklist

Most of the roofs we repair in May did not fail in May. They failed in January, quietly, under snow, and nobody was there to see it. A trailer that winters outdoors in Ontario is on duty every single day of the season whether it moves or not, and the roof is the part doing the work. This is the checklist we give owners who ask how to get a parked unit through to spring dry.

Before it goes into storage

• Get the sealant checked and touched up while temperatures still let it cure. This is the whole game
• Wash the roof and clear leaves, needles, and sap from the surface, the slide-out roofs, and the gutters
• Bring the slide-outs in. A slide roof left out all winter is a snow tray with a seal along the top edge
• Photograph the whole roof from a ladder. In spring you will want to know what changed
• Check the vent lids and skylight domes for cracks. A yellowed, brittle lid is one hailstorm from a hole

Cover, tarp, or nothing?

A fitted, breathable RV cover keeps UV, snow, and debris off the roof and lets moisture out. It is the best option short of indoor storage, and it can add years to sealant life. A plastic tarp is the worst option, worse than nothing. It traps condensation against the membrane, it chafes the lap sealant at every point it flaps in the wind, and it is the most reliable way we know to grow mould in a stored unit. If a proper cover is not in the budget, leave the roof bare and manage the snow.

Whichever you choose, the cover goes on after the sealant check, not instead of it. A small crack in October spends five months under ice either way.

How much snow is too much?

Think weight, not depth. Powder in January is light. The same depth of wet March snow can weigh several times as much, and a thaw-and-refreeze turns either one into ice that no roof rake will move. The working rule is to clear it once it builds past a hand width, and always ahead of a warm spell. Use a roof rake with a soft edge from the ground or a ladder, pull the snow off rather than pushing it, and never chip at ice with anything hard. A shovel on an EPDM roof leaves gouges that leak in spring.

Warning signs the load has already stressed the structure: ceiling panels that sag or ripple, an entry door that suddenly sticks, and new cracks at the roof seams after a heavy fall.

Ice damming happens on RVs too

Any place snow melts and refreezes at an edge can build a dam that holds meltwater against the seam behind it. On a trailer that means the roof edges, the front cap transition, and the low side of a slide roof. Keeping the snow load down is most of the prevention. Where a dam forms anyway, do not attack it. Wait for the thaw and get the seam inspected, because meltwater that sat against a seam for a week has usually found a way in.

The freeze-thaw problem

Every shoulder-season night, meltwater in a hairline crack freezes and expands, prying the crack wider for the next cycle. Southern Ontario can run dozens of those cycles between November and April. This is why sealant fails faster here than manufacturer estimates suggest, and why the fall touch-up matters more than the spring one: it closes the crack before the cycling starts.

When spring comes

Book the inspection before the first trip, not after the first rain at the campsite. What winter opened is easiest to fix while it is still a sealant job. If you sent us fall photos, the spring visit starts with a plan and a comparison rather than a search from scratch. Even a seal needs extra water protection, and a trailer that spent the winter outside needs it most.