Rytons A1® Fire-rated Cowl

General Details

Features and Benefits:

  • Custom-made surface mounted metal hooded cowl.
  • Made-to-measure cover for new or existing air bricks, grilles and vents.
  • Can be made to order in both large and small sizes.
  • Protects external grilles and vents from excessive environmental conditions such as rain and snow.
  • Reduces air blasts through ductwork or the cavity.
  • Manufactured from A1 classified galvanised steel.
  • Supplied custom powder coated to Class A2-s1, d0. Choose from the RAL Classic colour chart in matt, semi-gloss or gloss finishes to match cladding or brickwork. Signature architectural finishes are also available.
  • Bespoke design service available. For further information contact our Technical Sales Office on 01536 511874 or email admin@rytons.com.
  • Suitable for:
  • The external walls of high-rise relevant buildings over 18m high (11m high in Scotland).
  • The external walls of relevant buildings 11m+ in height or more than 5 storeys, undergoing unsafe cladding remediation work (Building Safety Act 2022).
  • The external walls of higher-risk buildings at least 18m high or with at least 7 storeys (Building Safety Act 2022).
  • The external surfaces of residential purpose group buildings more than 11m high.
  • The external surfaces of residential purpose group buildings 11m high or less where an external wall is within 1m of the relevant boundary.
  • All other residential and non-residential buildings.

A1 Fire Classification Explained:

  • Rytons A1® Fire-rated Cowl is made from galvanised steel. Galvanised steel is considered fire class A1 without testing, as per European Commission paper 96/603/EC referred to in BS EN 13501-1:2018.
  • Classification: A1. Definition: Non-combustible. Description: No contribution to fire.

Reference Material – Fire Safety:

  • England & Wales: view extracts >>
  • Approved Document B: Fire safety (Volume 1) (2019 edition incorporating 2020 and 2022 amendments) for England.
  • Approved Document B: Fire safety (Volume 2) (2006 edition incorporating 2010, 2013, 2016, 2017 and 2020 amendments) for Wales.
  • The Building Safety Act.
  • Scotland: view extracts >>
  • Building Standards Scotland Domestic Technical Handbook.
  • Northern Ireland: view extracts >>
  • Technical Booklet B (Materials and workmanship) July 2013.
  • Technical Booklet E (Fire safety) 2012.
  • Amendments Booklet – 2022 (AMD 7).


Rytons A1® Fire-rated Cowl
Surface mounted hooded cover for air bricks, grilles and vents.
Custom cowl opening width x height to cover vent/grille plus 15mm flange (with screw holes) top and sides. Note: Rytons recommend a cowl opening 10mm larger than the vent/grille for installation clearance.
Custom RAL colour in matt, semi-gloss or gloss finish achieving Class A2-s1, d0.
Properties: Class A1 fire-rated 0.9mm galvanised steel. Class A2-s1, d0 fire-rated RAL colour powder coating.
Product Code: A1COWL.
Download Drawing.  |  Download Golden Thread.


  • Position the cowl over the vent/grille.
  • Fix the cowl to the wall through the pre-formed holes in the flange using suitable fasteners.
  • Apply a bead of external weather resistant sealant around the flange to provide a seal against the wall.

Rytons is proud to be a family run business and British manufacturer since 1972

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