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Design of chip seals (P18)

Published: | Category: Construction , Chipsealing , Specifications | Audiences: Road traffic engineers & consultants, Roading contractors

P18 Specification for the design of chip seals sets out a client-prescribed method for the design of a range of chip seal techniques used in New Zealand.

P18 is a new document. It takes the design methods described in Chipsealing in New Zealand and its predecessor, the Bituminous Sealing Manual and presents them in the form of a technical specification.

The areas covered by the specification include:

  • materials
  • design parameters
  • binder selection
  • design algorithms
  • maintenance seals.

P18: 2025 specification is a new document.

Publication details

  • Author:
  • Published: June 2025
  • Reference: NZTA P18
  • Contact: pavements@nzta.govt.nz
  • Also known as: P/18