Preparing Commercial Roofs for Queensland Storm Season: An Owner's Checklist

Queensland's storm season runs from October through March, and the pattern repeats every year: the first severe cells arrive, roofs that were marginal in September fail in November, and roofing contractors spend the wet months on emergency make-safes instead of planned work. The roofs that come through cleanly are almost never lucky; they are maintained. This checklist is what a thorough pre-season preparation covers on a commercial building.

1. Clean the drainage system completely

Gutters, box gutters, sumps, rainheads, downpipes and overflow devices, all of them. A roof drainage system is sized as a chain, and one blocked sump takes the whole chain offline in peak rainfall. Box gutters deserve particular attention because they overflow into the building rather than over the edge. Confirm the overflows are actually clear: an overflow that was flashed over or meshed shut during earlier works is a flood waiting for its storm.

2. Check fixings and sheet security

Wind damage usually starts at a fastener. Cyclic loading works screws loose over years, and a sheet that flutters in a gust becomes a sail once the first fixing lets go. The pre-season check looks for backed-out screws, corroded fastener heads, deteriorated seals under screw heads, and fatigue around fixing points, with particular attention at ridges, edges and corners where wind pressures concentrate. Buildings in cyclonic regions have specific fastener patterns designed for their wind class; the inspection confirms the as-built pattern is still intact, not what it has eroded to.

3. Inspect sheets, laps and flashings

Surface rust, lifted laps, cracked or displaced flashings, and previous patch repairs all get examined. Flashings fail before sheets: ridge cappings, barge flashings, apron flashings at walls and parapet cappings take the brunt of wind and thermal movement. A flashing that has lifted 10 millimetres is a minor fix in October and an open roof edge in a December gust front.

4. Renew tired penetration seals

Every pipe, flue, conduit and plant penetration through the roof relies on a boot or sealant detail with a finite life. UV-aged silicone that has split or debonded will pass a dry-day glance and fail in wind-driven rain. The pre-season pass re-seals or replaces the marginal details while the roof is dry, which is also when sealants cure properly.

5. Skylights, vents and ridge ventilators

Polycarbonate skylights become brittle with UV age and shatter under hail. Check for cracking, crazing and insecure fixing, and replace units that have gone chalky. Vents and ventilators are inspected for loose cowls and corroded bases, both of which become projectiles in severe wind.

6. Test the drainage under load

A hose run into each gutter section proves what visual inspection cannot: that water actually reaches the downpipes and leaves the site. Slow drainage points to silted lines or flat grades below ground, problems that surface as roof flooding even when the roof itself is clean. Where leak history exists, pre-season is the right time for proper leak detection rather than waiting to chase water through a live storm.

7. Manage trees and loose items

Overhanging branches abrade roof surfaces and feed the gutters with debris all season. Anything loose on the roof, redundant plant, leftover materials, unsecured walkway mesh, gets removed or fixed down. After a storm, half of the damage on neighbouring roofs is often from items that took flight from somewhere else.

8. Document the roof's condition

Photograph the roof, the gutters and the plant areas, and file the inspection report with the date. If a storm claim follows, the insurer's first questions are about maintenance, and a documented pre-season inspection answers them. Insurers can and do reduce or decline storm claims where damage traces to long-term lack of maintenance rather than the storm itself; the records are the difference between those conversations.

9. Have an emergency response plan

Even well-maintained roofs can take hail or a microburst. The plan is simple: who calls whom, which contractor attends make-safes, where the isolation points are for services, and what tarping or temporary weatherproofing can be deployed fast. Buildings with a standing roof maintenance arrangement get priority response in storm aftermath, when every roofer in the city is triaging calls; buildings ringing cold join the queue.

10. Know your roof's wind class assumptions

Every roof was designed to a wind load, and alterations erode the design quietly. New rooftop plant changes local wind behaviour, extra penetrations interrupt fixing patterns, and replacement sheets fixed with fewer screws than the original schedule carry less capacity than the design assumed. Owners do not need to become engineers; they need to know that the fixing schedule on the drawings is a safety document, and that any roof work done over the years should have matched it. Where the building's history is murky, a fastener audit during the pre-season inspection closes the question for a modest cost, and it is precisely the kind of record an insurer responds well to after a wind event.

Timing

Book the inspection for September or early October. Contractors have programme capacity then, repairs can be done in dry weather, and sealants and coatings cure properly. By mid-November, severe weather is already arriving across Brisbane and the Gold Coast, and the window for planned work has closed for the season.

Allied Commercial runs pre-season roof inspections and storm make-safe response for commercial buildings across south-east Queensland. To get your roof checked before the season, book an inspection.