One-piece and two-piece arrangements
A one-piece S-profile combines a raised roll and a drainage channel in a single field tile. Traditional two-piece Mission arrangements use separate pan and cover components. Both can create a strong repeating curved pattern, but their unit counts and installation details differ. Confirm the actual product: regional names and catalog terminology are not completely interchangeable.
Read the roof from several distances
From a distance, compare the size and spacing of the rolls, the shadow at the eave and the character of hips and ridges. Up close, compare the openings, overlaps and accessory shapes. A replacement that matches color but changes these relationships can noticeably alter a historic building. Record representative roof elevations and details before selecting a substitute.
Estimate by the correct components
For a two-piece system, account for pans, covers and special pieces using the manufacturer’s coverage information. For a one-piece system, use that product’s installed exposure and accessory schedule. Neither should be estimated from a generic count for “barrel tile.” Ask the installer to show how the field pattern terminates at the eave, verge, valley, hip and ridge before the order is finalized.
Further reading & technical sources
- National Park Service · Preservation Brief 30 ↗
- Ludowici · Spanish 13 profile ↗
- Ludowici product technical documentation ↗
Consult the current product documentation and local requirements for your project. These introductions are not installation specifications.
More tile roofing guides
- French interlocking clay roof tile
- Roman pan-and-cover clay roof tile
- Flat clay shingles and double-lap roofs
Tile Roofing USA editorial guide · Published October 28, 2026.