Minimum Roof Pitch for Tiles: Clay, Concrete & Plain Tiles
Tile minimums differ by country and tile type. The US code allows clay and concrete tile from 2½/12 (11.8°) with double underlayment below 4/12; Australia’s AS 2050 covers tiled roofs from 15°; and UK double-lap plain tiles need 35°.
Minimum pitch by system
| Roofing system | Minimum pitch | Conditions | Source |
|---|---|---|---|
| Clay & concrete tile (US), with double underlayment below 4/12 | 2½/12 (11.8°) | — | IRC R905.3.2 |
| Concrete & terracotta tiles (Australia) | 15° (3.22/12) | AS 2050 applies from 15°; below that, follow the tile manufacturer | AS 2050 |
| Plain tiles, clay or concrete (UK, double lap) | 35° (8.40/12) | Minimum 65 mm headlap; 75 mm in severe exposure for clay | NHBC 7.2.19 |
| Interlocking single-lap tiles (UK) | Product specific | Use the manufacturer data sheet for your exposure zone and rafter length | Manufacturer |
Plain tiles vs interlocking tiles
Plain tiles are small, double-lap tiles: every point of the roof is covered by at least two tiles, which is why they need a steep 35° pitch to shed water fast. Interlocking tiles are single-lap with side channels, so many profiles are rated for much lower pitches. Always use the minimum on the tile manufacturer’s data sheet for your exposure zone and rafter length.
Frequently asked questions
What is the minimum roof pitch for roof tiles?
Tile minimums differ by country and tile type. The US code allows clay and concrete tile from 2½/12 (11.8°) with double underlayment below 4/12; Australia’s AS 2050 covers tiled roofs from 15°; and UK double-lap plain tiles need 35°. Full list: Clay & concrete tile (US), with double underlayment below 4/12: 2½/12 (11.8°); Concrete & terracotta tiles (Australia): 15° (3.22/12); Plain tiles, clay or concrete (UK, double lap): 35° (8.40/12); Interlocking single-lap tiles (UK): Product specific.
Can I use roof tiles below the minimum pitch?
No. Below the minimum the covering is not code-compliant and manufacturers will not warrant it, because water drains too slowly and can be driven under laps. The lowest option on this page is clay & concrete tile (US), with double underlayment below 4/12 at 2½/12 (11.8°); below that, choose a different roofing system from the minimum pitch chart.