Metal roof cost calculator: Metal Roof Installed Price Index

Every row is a verbatim sentence read from the named source's own page through our fetch service on the date shown, hash-pinned to the stored read (the sha of the page's visible text; the raw page is mirrored to R2).

14 of the 35 named sources that could be read published a usable figure; 21 published none and are recorded as not published, never filled in; 0 could not be read (blocked, dead or unreachable) and count nowhere.

The headline figures (median, minimum, maximum, quartiles) are over ONE figure per source in USD (a source's median where its page yielded several accepted sentences), so N counts sources, never sentences; 313 candidate sentence(s) were refused by a reviewer with the reason recorded.

The fuller derivation this dataset is chartered to grow into (not yet what the figures above are; they are each source's own published figure as read): every installed price a US roofing contractor or metal roofing company states on its own page, normalised onto one grid - panel system (standing seam, exposed-fastener corrugated / R-panel / 5V, metal shingle, stone-coated steel), metal (steel, aluminium, copper, zinc), gauge (29, 26, 24), and unit (per square foot, per square, per project) - giving the median, the interquartile spread and the low-high range per panel system, the premium standing seam commands over exposed fastener, the share of publishers quoting a range wider than 2x (the market's own admission that the number is unquotable), and the DUPLICATE MAP: which publishers restate another publisher's sentence verbatim, so the index is computed over independent publishers only.

Nobody computes any of that; every guide restates a range.

313 candidate sentences on these pages were refused by a reviewer; each refusal and its reason is recorded in the review ledger.