Rytons A1® Fire-rated Round Return Grille with Spigot

General Details

Features and Benefits:

  • A round metal grille with spigot and flange tailor-made to any diameter required.
  • Made from Class A1 fire-rated galvanised steel and compliant with regulations for the requirement of non-combustible materials in the external walls of high-rise buildings over 18m (11m in Scotland) and those 11m and above undergoing unsafe cladding remediation work.
  • 15mm wide flange covers cut edges to maintain a neat appearance in cladding.
  • 25mm deep spigot provides a positive attachment for ducting.
  • Custom powder coating as standard.  Choose from the RAL Classic colour chart in matt, semi-gloss or gloss finish (achieving Class A2-s1, d0) for a grille that matches cladding or brickwork.  Signature architectural coatings are also available.
  • Built-in weather protection with angled grilles promotes runoff, reducing the risk of water transfer into the cavity or ducting.

A1 Fire Classification Explained:

  • Rytons A1® Fire-rated Round Return Grille with Spigot 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.  The material remains robust at elevated temperatures and has a high melting point temperature of 1450-1520° C.  Classification: A1.  Definition: Non-combustible.  Description: No contribution to fire.


  • The installation of metal grilles alone will not satisfy the requirements of high-rise buildings which require all materials forming part of the external wall, or a specified attachment, to be made from non-combustible materials.  For compliant ducting kits, see Rytons A1 Fire-rated Range.

Reference Material:

  • Building Regulation 7(2) – Ban of combustible materials in the external wall of buildings.
  • Building Regulation Approved Document B (fire safety).
  • Building standards Scotland technical handbook – domestic (2.7).


  • If this grille does not meet your requirements, we offer a bespoke service to design, fabricate and supply the perfect solution.  To discuss your requirements, call our technical sales office on 01536 511874 or email admin@rytons.com.

Rytons A1® Fire-rated Round Return Grille with Spigot
Custom RAL colour in matt, semi-gloss or gloss finish achieving Class A2-s1, d0.
Custom overall diameter grille (including 15mm flange – refer to drawing).
Custom spigot diameter 25mm D. Note: Rytons recommend a dia. at least 3mm smaller than ducting.
Custom screw holes (quantity and positioning).
65mm L Return Grille louvres. Note: The number of louvres will vary depending on the size of the grille.
Free area is dependent on the size of the grille.
Properties: Class A1 fire-rated 0.9mm galvanised steel. Class A2-s1, d0 fire-rated RAL colour powder coating.
Registered Design 6180109.
Product Code: A1SPECIALRRG.
Download Drawing.


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