Establish the roof’s character before judging condition
Map the main roof planes and record profile, color range, texture, visible exposure and ornamental pieces. Note areas that appear to belong to different construction or repair campaigns. NPS emphasizes identifying the qualities that give a historic roof significance before repair begins. This record lets later decisions distinguish authentic variation from damage or an incompatible previous alteration.
Locate each observation on a roof plan
Use consistent identifiers for slopes, dormers, ridges and other distinct features. Link photographs to those identifiers, with separate entries for missing pieces, fractures, displacement and surface deterioration. GSA calls for annotated drawings or photographs and a description of proposed work. Location-specific records prevent a general statement about roof condition from obscuring a problem confined to one area.
State the limits of the examination
Explain what was visible from the ground, what was inspected closely and which areas remain concealed or inaccessible. An initial visual review is not the same as a complete material assessment. GSA requires external and internal inspection for its repair submittals. Identify any further investigation needed before the team uses sample observations to make decisions about the whole roof.
Separate the tile from the underlying problem
A roof can have sound historic tiles while another part of the assembly needs attention. Conversely, an apparently orderly surface can contain deteriorated tiles. Record those findings separately and refer system diagnosis to the appropriate professional. Avoid deciding that all original material must be discarded simply because access beneath it or work at adjoining features is necessary.
Make the recommended treatment accountable
For each area, record the proposed outcome: retain in place, carefully remove and reuse, investigate further or replace with an identified match. Explain the evidence supporting that choice and any unresolved sample approval. Counts and percentages are useful summaries, but they should follow the condition map. The final record should show why material is being retained or removed.
Related questions
Further reading & technical sources
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.