May 13, 2024

Remediating Plastic HVAC Ducting Without Internal Access

As part of the remediation of unsafe cladding on relevant buildings 11m+/5 storeys in height, any plastic HVAC supply and extract ductwork forming part of the external wall must be replaced with a compliant non-combustible system to A1 or A2-s1, d0 classification.

However, replacing the ductwork can be complex if there is no access to the apartments. No access. No problem with Rytons A1® Fire-rated Retrofit Ducting Kits.

Whether the requirement is for round or rectangular ductwork, we have a comprehensive range of non-combustible, A1 classified, retrofit ducting kits. Unlike our standard kits which pass through the cavity board to the inner leaf, retrofit kits are fixed to the cavity board by a wide flange at the end of the duct. The oversized metal ducting then encases and protects in-situ plastic ducting that passes through the cavity board and cannot be replaced due to access issues.

50mm wide flange aids secure fixing to the cavity board

Oversized metal ducting encases in-situ plastic ducting

Rytons Retrofit Ducting Kits are available in round and rectangular options. Three round ducting kits accommodate 100mm, 125mm and 150mm diameter ducting. Rectangular kits are available across four ranges in two designs – straight and 90° for balcony locations. As non-combustible retrofit ducting specialists, our technical sales team are also on hand to discuss bespoke commissions using Rytons A1SPECIAL design service.

Custom-made, all ducting kits are supplied ready to install in the required length and with a RAL powder coated air brick or grille – saving time and ensuring a great aesthetic finish.

For further information, or to discuss any non-combustible ventilation requirements, please do not hesitate to call our technical sales office on 01536 511874 or email

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