Roof leak repair in Melbourne that starts by finding where the water actually gets in

Under every tile or metal roof is a layer of sarking, a foil or membrane sheet laid over the rafters, and under that a grid of timber battens. When water gets past the roof covering it lands on the sarking and runs downhill. It follows the batten it meets, pools against a rafter, finds a nail hole or a lap in the foil, and drops onto the ceiling plaster from there. On a shallow-pitched roof it can travel several metres sideways before it lands. The stain marks where the water came out of the roof cavity. It says very little about where it went in.

That is why a repair aimed at the stain fails. Someone climbs up, finds a tile roughly above the wet patch, seals it or swaps it, and the ceiling is wet again after the next decent rain because the real entry point is two metres uphill on the other side of a valley. We see the results of that approach every week: three layers of silicone around one vent, a new tile in a field of sound tiles, and a leak that never stopped.

Leak detection on a roof is a process of following the water backwards. The crew starts at the stain, finds the wet timber above it in the roof space, traces the run uphill along the batten to the highest wet point, and then goes onto the roof directly above that spot. More often than not the fault is there, and it is small.

Most leaks we trace end at one of a short list of faults, and the roof type narrows it fast. On tile roofs the common entry points are a cracked or slipped tile, a valley iron rusted through under a bed of leaves, ridge capping whose mortar has crumbled and let the caps lift, and torn or perished sarking that no longer carries wind-blown water to the gutter. On metal roofs it is fixings: screws that have backed out, rubber washers perished by the sun, an open lap between sheets, or rust along the lower edge where the sheet sits in wet gutter silt.

On either roof the joins fail first. Wall flashings pull away from mortar chases, penetration flashings around exhaust cowls, flues and whirlybirds lift or were never fitted with a back tray, and skylights leak at the flashing far more often than at the glass. Anything added after the roof was built is suspect: solar conduits, aerial mounts, a new ducted heating flue.

And a good share of ceiling leaks are not roof leaks at all. A blocked gutter or box gutter fills, backs up under the bottom row of tiles or the sheet edge, and comes in over the wall plate. The ceiling is wet, the roof is fine, and the fix is a gutter repair or a clean. We check the gutters on every leak call for that reason.

Once the entry point is found the repair is usually specific and small, and it goes to the trade that owns it. Flashing faults, rusted valleys, loose fixings and metal sheet repairs are carried out by licensed roof plumbers. Cracked tiles, slipped tiles and ridge capping are handled by roof tilers. If the leak is at a skylight, the flashing and seal are re-done. If it is at a chimney, our chimney flashing repair crew takes it, because chimney leadwork is its own job.

Each of those repairs has its own page with the detail: roof flashing repair, valley iron replacement, ridge capping repair, roof tile replacement, Colorbond and metal roof repair and skylight leak repair. You do not need to know which one you have before you call. Describe where the water shows up and what the roof is made of, and the office sends the right person.

While the crew is up there they look at the rest of the roof, because a roof with one rusted valley usually has a second one on the way. Anything they find is photographed and goes in the same report, and it is your call whether to fix it now or later. The firm price covers the scope the office confirmed and nothing gets added without your say-so.

You cannot see your own roof, so the record matters. On every leak job the crew photographs the wet timber or plaster inside, the entry point on the roof before it is touched, and the repair when it is done. You get all three sets. If the roof space is accessible, the run of the water along the batten is photographed too, so you can see for yourself why the fault was not above the stain.

That report has a second use. A slow leak is usually traced to a fault that has been developing for a while, and how an insurer treats that is a question for them and your policy, not for us. We do not label a leak to suit a claim and we never promise what an insurer will do. What we can do is document the cause plainly, in dated photos and a short note, so that if you choose to claim you are handing over a record rather than a description. If the leak started with a storm – a sheet lifted, tiles cracked by hail, a branch through the roof – our storm damage roof repair page covers the make-safe and the report in more detail.

Every leak job comes with a free estimate over the phone, a firm price from the office before any work, no call-out fee, and payment after the job. If it turns out to be a gutter and not the roof, we say so and fix the gutter.