Solar on tile roofs in Perth: terracotta, concrete, and slate

Tile roofs — terracotta, concrete, and occasionally slate — are extremely common on Perth homes built between the 1980s and early 2000s. If your home has a tile roof, solar installation is straightforward, but the specific tile type, age, and condition affect how the installation is done and what it costs.

Types of tile roofs in Perth

Terracotta tiles: Fired clay, reddish-brown or natural terracotta colour. Common on older Perth homes (1970s–1990s). Heavier than concrete tiles. Generally more brittle, particularly older examples that may have become more fragile over decades of Perth summer heat cycling. High quality — a well-maintained terracotta roof can last 50+ years.

Concrete tiles: Grey, textured, often painted in slate grey or ochre. More common on 1990s–2000s Perth tract housing. Lighter than terracotta. Some concrete tiles have a surface coating that weathers over time, which can make colour-matching or tile replacement after installation work harder (if tiles are broken during work).

Monier tiles: A brand of concrete tile widely used in Perth. Available in various profiles (flat, S-curve, low-pitch). Well-documented mounting requirements with most Perth solar installers experienced in Monier roof work.

Slate: Genuine slate is relatively rare in Perth. More common to find imitation slate (concrete or fibre cement pressed to look like slate). If genuinely slate, consult a specialist roofer before solar installation.

How solar is mounted on tile roofs

The tile mounting bracket process:

Installing solar on a tile roof involves:

1. Locating the roof rafters beneath the tiles
2. Lifting specific tiles (without breaking them)
3. Drilling a lag bolt through the sarking/battens into the rafter below
4. Installing a tile mounting bracket (aluminium bracket with a flashing flange that sits under the adjacent tiles)
5. Replacing the tiles around the bracket
6. Attaching the railing system to the brackets
7. Sliding panels onto the railing

The critical skill is replacing tiles without breaking them. Experienced Perth solar installers have done this hundreds of times. Less experienced installers may crack or chip tiles — ask about the installer's tile-roof experience specifically.

Flashing quality: The flashing around each bracket point is what prevents water ingress. Low-quality or incorrectly installed flashing is the primary source of roof leak complaints after solar installation on tile roofs. Ask installers about their waterproofing process and whether they offer a dedicated roof penetration warranty.

Old vs new tiles: condition matters

Age and brittleness: Terracotta tiles over 30 years old can become more brittle from thermal cycling and Perth's UV exposure. Walking on older tiles and lifting them for mounting bracket installation is riskier. Experienced installers use tile hooks and crawl boards to distribute weight and avoid cracking.

Replacement tile availability: If tiles are broken during installation, matching them can be difficult for discontinued tile profiles or colours. Before installation, confirm the tile type and check if replacement tiles are available. For older, difficult-to-match tiles, some installers keep a small buffer of lifted tiles available to replace cracked ones.

Weathered concrete surface: Older concrete tiles that have lost their surface coating (they appear chalky or bleached) may not accept repair paint well. This is cosmetic, not structural — but worth noting if maintaining appearance matters.

How many tiles are lifted for a typical Perth installation?

For a 10kW system with 6–7 mounting rails and approximately 24–28 mounting points, expect 48–56 tiles to be lifted during installation (each bracket point requires lifting the tile above it and the bracket tile itself). On a 200-tile standard pitch roof, this is a meaningful proportion of the roof surface. Each tile must be carefully lifted, the bracket installed, and the tile replaced and re-bedded.

Perth CEC-accredited installers with tile roof experience typically allocate additional time for tile roof work versus Colorbond:

• Colorbond: 4–6 hours for a 10kW system
• Tile roof: 6–10 hours, sometimes more for older terracotta

Roof pitch and shading on tile roofs

Perth tile roofs are typically pitched at 22.5°–30° — close to the optimal for Perth (approximately 32° at Perth's latitude of 31°S). This means tile roofs are inherently well-pitched for solar without requiring additional tilt racking. The primary orientation consideration (north-facing is optimal; east/west acceptable; south-facing is poor for Perth) applies the same as any other roof type.

Post-installation roof maintenance

After solar installation on a tile roof:

• Don't walk on tiles around the racking: The racking changes how weight distributes near mounting points. Walking on tiles in these areas increases crack risk.
• Annual visual inspection: Check flashings around mounting brackets from the ground (binoculars help). Lifted or degraded flashing is a potential leak point.
• Gutter maintenance: Perth's autumn leaf drop and spring pollen can clog gutters. Blocked gutters near racking can cause water to back up under tiles.

Tile roof and panel removal for re-roofing

If your tile roof will need replacement in the next 5–10 years, plan the timing:

• Removing solar for a re-roof and reinstalling costs $1,500–$3,000 in Perth
• If your roof is already 25+ years old and approaching end of life, consider replacing tiles before solar installation to avoid this cost

Ask your installer for a tile roof condition assessment as part of the site inspection.

Perth tile roofs — terracotta and concrete — are standard for solar installation and represent no unusual barrier. The key differences from Colorbond are the tile mounting bracket process (drilling into rafters, flashing around each bracket) and the care required with older or brittle tiles. Experienced Perth installers have extensive tile-roof experience; ask specifically about their tile roof installation process and waterproofing approach.