01
The assembly, not just the finish
Tile roofs combine tiles with underlayment, flashing, attachment and structural support. TPO roofs use a membrane system with seams, perimeter and penetration details selected for the building. Slope, drainage, existing deck condition and loading drive the comparison. A steep-to-low-slope transition detail is not approval to place clay tile over any TPO membrane.
GAF · steep-to-low-slope transition detail02
Ownership and maintenance
Compare access for inspecting flashings, drains and penetrations rather than assuming either covering is maintenance-free. Roof traffic and future solar or equipment work should be coordinated with the chosen assembly. Ask what inspection and cleaning documentation the supplier provides; do not infer a service life from material type alone.
03
What the proposal must include
Require tear-off, assessment of the deck, any designed reinforcement, drainage, edge/penetration details, ventilation coordination, access protection and disposal. Separate hidden-condition allowances from confirmed replacement scope. Warranty terms, if offered, must come from the actual proposed assembly and contract, not this guide.
04
Resolve before procurement
Have the design team and roofer resolve slope, structural loading and water discharge before selecting a visual finish. Confirm current approval requirements with the parcel authority. This page does not provide fastening patterns, slopes or reroofing rules.