Why does water get in when the tiles still look fine?

Tiles overlap. They do not seal a storm

A tiled Melbourne roof sheds water down the face of each unit and off the nose onto the course below. In ordinary rain that is enough. In a wind-driven southerly, water is pushed up the lap, through a hairline at the ridge, or off a saturated valley. Sarking — the foil or heavy underlay over the rafters, under the battens — is there to catch that water and let it run to the eave. When people say the roof leaked even though the tiles look tidy, they are often describing a second line that was never renewed when the face was painted.

The layer also cuts dust and a share of heat, which is why it gets mentioned beside insulation. The leak job is the one that stains a ceiling. Roof Revival Melbourne separates those reasons so a quote for new sarking is not bundled into a colour you did not need, and a colour is not sold as if it repaired a tear you cannot see from the driveway.

Older roofs vary. Some interwar and post-war tile roofs have no sarking at all. Some have a paper that has cracked and dropped. Some later roofs have foil that has been walked through, cut for downlights, or torn around a flue. Each of those is a different scope. The phrase “the roof needs sarking” is only the start of the sentence.

How a stain appears under a tidy course

Water that passes the lap hits the sarking and should run to the gutter. If the sarking sags between rafters, it forms a pocket. The pocket holds water until it finds a nail hole, a join or a split, then releases it onto the ceiling in weather that may not be the peak of the storm. The tile above the stain can be perfect. The pocket sits further up the pitch, and the drip falls where the plaster is weakest.

A missing patch shows itself more honestly. From the manhole you can often see the underside of the tile, or a sheet hanging like a curtain. Insulation that has slumped and darkened is a map of where the second line gave up. It is not proof the whole field of tiles is finished. It is proof the ceiling has been doing a job the underlay was there to do.

Ridges and valleys confuse the picture. An open hip can wet the sarking so often that the foil fails along that line only. Replacing a whole roof because one hip has rotted the underlay is the expensive reading. Resetting the hip and replacing the damaged underlay is the reading Roof Revival Melbourne will write when the roof space shows that pattern.

When the tiles should come off that plane

Sarking sits under the battens. A new sheet cannot be slid in from the manhole and called a roof. Replacing it means the tiles come off that plane, the battens come off, the new underlay goes down, and the assembly goes back. If the tiles are hard and the profile can be relaid, they go back. If the tiles are soft, this is the moment the conversation becomes a replacement, because the roof is already open to the timber. Relaying finished tiles, then paying to remove them again, is the waste to avoid.

A local tear under one drip can sometimes be a local repair if the cause above it is fixed and the rest of the underlay is sound. A roof where the foil has perished across the plane is not a tape job. Tape on the underside is a temporary courtesy to the ceiling, not a specified system. Roof Revival Melbourne will say which of those you have. The manhole often makes it obvious before the street does.

This page does not set out a method for lifting tiles or fixing underlay. The decision is whether the second line is the failed part. Climbing a steep roof to check it yourself is how a sarking question becomes a fall.

What else is visible once the plane is open

With the tiles off, the battens are visible. A batten that has cupped, rotted at the fixing, or been notched until it no longer holds a tile belongs in the same scope. New sarking under a batten that will not last the underlay is a short repair. The lower edge also has to drain. If it cannot discharge toward the gutter, the new layer wets the fascia instead of saving the ceiling. That detail belongs on the quote.

Valleys, aprons and penetrations have to meet the new underlay. Foil that disappears into a rusted valley still leaks. Roof Revival Melbourne lists those junctions when they are part of why the ceiling stained. A sarking price that assumes every flashing is fine is only fine when someone has looked.

Insulation and downlights complicate the space. The quote should say whether insulation is moved and put back, and whether any fitting that was cut through the old underlay is detailed properly this time. The same hole in the new layer repeats the stain in a neat square.

How this sits beside a restoration

A restoration prepares, repairs, resets ridges and coats a sound tile. It does not automatically replace sarking. If a quote for a new colour is silent on the underlay, and you already have a stain or a torn sheet visible from the manhole, ask before you sign. You may still want the restore. You may need the sarking in the same program, so you are not coating a roof that wets the plaster from underneath.

The reverse matters too. Failed sarking is not a reason to accept a full replacement if the tiles and the frame are sound. The larger job is easier to sell because the underlay is harder to see. Roof Revival Melbourne would rather open the plane that needs it, relay the good tiles, and leave the colour for when the tile body asks for it.

What to photograph before the call

From the manhole, with a torch, and only if you can stay on the access without stepping through the ceiling, look for hanging foil, dark droops, daylight, and insulation that has become a wet mat. From outside, note whether the tiles look even and whether the ridges are open. A tidy tile plus a tear in the roof space is the pattern this page describes.

Send the suburb, the storeys, a photo of the stain, and a roof-space photo if you can take one safely. The tiles can look fine. The second line still has to carry the water the lap was never meant to stop on its own.