What underlayment does
Underlayment helps manage water that reaches beneath the tile covering. Its condition and detailing matter even when the visible tiles appear sound. A leak assessment should include the underlying layers.
When lifting and relaying is considered
A contractor may propose removing serviceable tiles, repairing the deck and underlying layers, then reinstalling the sound tiles with compatible replacements. Suitability depends on condition, breakage, availability and the required attachment system.
Ask what is included
Request a written allowance for broken tiles, deck repairs, replacement flashing, penetrations, disposal and temporary weather protection. Ask how tiles will be sorted, protected and matched during the work.
Choose the system for the project
There is no universal underlayment specification for every tile roof. Have your roofer identify the applicable manufacturer instructions, regional installation guidance and local requirements.
Further reading & technical sources
- Tile Roofing Industry Alliance installation guides ↗
- Building America Solution Center · Clay or Concrete Tile Roofs ↗
- National Park Service · Preservation Brief 30 ↗
Consult the current product documentation and local requirements for your project. These introductions are not installation specifications.
Tile Roofing USA editorial guide · Published October 26, 2026.