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Irish Roof Pitch: Product, Exposure and Design Checks

Choose an Irish roof pitch from the specified system, exposure and design requirements. Check product limits, laps, fixings and applicable standards.

TGD Part C (2023 amendment) Clause IE TGD C

Check the roof product and the site

There is no single pitch in this guide that you can use for all Irish roofs. Tile, slate and sheet systems have different limits. Get the current specification for the exact roof covering before you set the roof out.

The project must also meet the Irish building rules. A product’s stated minimum pitch is only one check. It does not settle wind loads, fixings, laps, underlay, drainage or the strength of the roof.

What to confirm

  • The roof covering, profile and system used in the design.
  • The maker’s pitch limits for the site’s wind and rain exposure.
  • The required laps, fixings, underlay and details at roof junctions.
  • The standards named in the design brief and which editions to use.
  • Any product certificate’s scope and conditions.

Keep the design, product sheets and installation records together. Do not swap a product on the basis of pitch alone. Ask the roof designer to check the effect of the change.

Sources and limits

Technical Guidance Document C is the official moisture-resistance guidance. The full current PDF could not be rechecked in this review. Check its roof clauses as well as the product rules for your job.

Check specified Irish standards through NSAI. Full paid standards and the chosen roof system still need review for the job. A roof still needs a design for the site and system used. Content scope checked on 6 September 2026.

Irish building-code hub.

Related building rules