Reviewed, sourced guidance
Corrections and source updates
Direct answer
The source labels show when a page was checked, and the calculator method records its model version. No public correction form or contact address is active on this preview.
This preview shows dated source observations and a versioned calculation model. It does not accept project details or correction submissions.
Key takeaways
- Source observations are dated on the page where they are used.
- The estimator displays a version for its calculation assumptions.
- No correction inbox or project-data form is active.
How sources are reviewed
Product quantities remain linked to the named source, product and stated unit. A changed source should trigger a review of every page and formula that uses it.
The displayed observation date is not a promise that a manufacturer has approved this estimator.
- Technical product figures stay scoped to the named system.
- Safety guidance is cited to the Health and Safety Executive.
- Price observations are labelled with their survey date and tax boundary.
Sources for this section: Marley, Duo Modern product data (observed 2026-09-25)Marley, Universal HipFast system and box contents (observed 2026-09-25)Health and Safety Executive, Roof work (page updated 2026-06-05; observed 2026-09-25)Which?, How much do roof repairs cost? (observed 2026-09-25)
Correction submissions are not open
This preview has no public contact address or correction form. Do not submit property measurements, contact details or other project information through the calculator.
A submission route can be added only after the site operator, privacy notice and contact channel are approved.
- No lead capture or provider routing runs on this preview.
- Calculator inputs remain in the browser and are not submitted by the form.
- The page can be updated when the source or calculation changes.