Roof Tiles: What to Know

Roof tiling is one of those parts of a build that most homeowners never really get to inspect, largely because it’s inaccessible for them. But that doesn’t mean roof defects can’t be identified early, or that they should be ignored until problems appear inside the house.

We are going to discuss practical ways homeowners can assess roof tiling without putting themselves at risk, what to look for when inspecting, and where defects most commonly arise during construction. Roof tiles form a primary weather barrier, and when something goes wrong, the damage often isn’t always obvious straight away. Water ingress may not show up until long after the build is complete, by which time framing, insulation or plasterboard may already be affected.

Many of these issues are far easier to deal with before the internal linings are installed, which is why timing and inspection approach is important.

For single-storey homes, a surprising amount can be checked from the ground. A basic visual inspection allows homeowners to see whether tiles appear to be in place, whether ridge and capping tiles look straight, and whether there are obvious signs of displacement or misalignment. Using a phone camera or a selfie stick can provide better angles without the need for ladders or roof access equipment.

Drone inspections are another option and can be particularly helpful for double-storey homes, but they do come with limitations, especially for inexperienced users and people who don’t really know what they’re looking for. Wind and rain can restrict their use, and drones often can’t get close enough to inspect fine details, especially around penetrations or under solar panels. For that reason, drone footage should be treated as supplementary rather than definitive.

When inspecting a tiled roof, one of the first things to look for is whether all tiles are properly seated and evenly aligned. Misaligned or displaced tiles can affect how water drains into the gutters and increases the risk of leaks. Ridge and hip capping tiles deserve particular attention. These are the tiles that run along the apex of the roof along the hips (at the corners) and are secured using bedding and pointing. Bedding is the mortar that sits beneath the capping tile to hold it in position, while pointing is the flexible, rubberised compound applied over the joint. Capping tiles should appear straight and consistent, with no visible gaps underneath. Minor hairline cracking in pointing can occur and isn’t always a defect, but significant or widespread cracking is generally not acceptable and should be raised with the builder.

Another detail that is often overlooked is how far roof tiles project into the gutter. In Victoria, tiles are required to project into the gutter by around 50 to 65 millimetres. If they fall short of this, water can affect eaves, fascias and external walls over time.

Some of the most common roof tile damage doesn’t occur during the initial installation, but later when other trades access the roof. Areas around plumbing penetrations, antennas, solar panel brackets and roof access points are particularly vulnerable.
Trades walking on tiled roofs can easily crack tiles, especially if weight is applied incorrectly. Solar panels introduce an added layer of risk because there can be broken tiles underneath them and remain completely hidden from view. In these cases, damage may only become apparent once water starts entering the roof space.

This is why inspecting the roof from inside the roof cavity can be so valuable. One of the best times to do this is after the frame stage is complete but before plasterboard is installed. From inside the roof space, it may be possible to see broken or displaced tiles, poorly installed flashings, or daylight where it shouldn’t be visible. It’s important to understand that some small gaps are normal. Roof tiles overlap both sideways and top to bottom, so depending on the angle, you may see light through small gaps that aren’t defective. However, broken tiles, obvious gaps around penetrations, or missing or poorly installed flashings should be raised immediately.

Flashings themselves are one of the most common sources of roof leaks. Wherever a pipe or penetration passes through a roof tile, a flashing must be installed. The flashing is tucked under the tile above and wrapped around the penetration to prevent water from entering between the pipe and the tile cut-out. When flashings are poorly installed or missing altogether, water ingress is almost inevitable, even if the tiles themselves appear intact.

Focusing on ridges, penetrations, gutters and areas that have been accessed by other trades can reveal early warning signs. Solar panels increase the risk of hidden damage, and the best inspection window is before internal linings go in. Raising concerns at this stage is far easier than dealing with roof leaks after wards, when access is limited and rectification becomes more disruptive and costly.