28mm Pipe Insulation

28mm pipe insulation fits copper and plastic pipe with a 28mm outside diameter — widely used for larger domestic heating systems, commercial hot water supply, primary heating circuits and chilled water pipework. We stock every type of 28mm pipe insulation from the UK's leading manufacturers including Armaflex, K-Flex, Rockwool and polyethylene foam, in wall thicknesses from 9mm to 40mm.

Types of 28mm Pipe Insulation

Armaflex EVO 28mm — Class O closed-cell nitrile rubber foam with built-in vapour barrier. The professional's choice for HVAC, chilled water and condensation-sensitive applications. Available in 9mm, 13mm, 19mm and 25mm wall, standard and self-seal
K-Flex ST 28mm — Class O elastomeric foam, equivalent performance to Armaflex at a competitive price. Available in 9mm, 13mm, 19mm and 25mm wall
Rockwool Rocklap 28mm — Mineral wool with foil facing for high-temperature applications up to 750°C. A1 non-combustible. Ideal for steam, high-temperature heating and fire-rated installations
Tubolit DG 28mm — Cost-effective polyethylene foam lagging for standard domestic heating and plumbing. Not suitable where Class O fire rating or condensation control is required

Which Wall Thickness Do I Need?

9mm wall — Condensation control on chilled water and cold pipework in conditioned spaces
13mm wall — Standard for domestic heating and hot water. Meets Part L Building Regulations for most domestic applications
19mm wall — Enhanced performance for commercial HVAC, chilled water and exposed pipework. Meets Part L for commercial heating
25mm wall — Maximum performance for chilled water, refrigeration and unheated spaces
30–40mm wall — Heavy commercial and industrial heating mains, steam pipework and high-temperature applications (Rockwool)

BS 5422 for 28mm Pipe Insulation

For LTHW commercial heating on 28mm OD pipework, BS 5422 requires a minimum of 25mm Kooltherm or 19mm Armaflex EVO. Read our full guide: BS 5422 Pipe Insulation Standards Guide.

28mm Pipe Insulation — Common Applications

Larger domestic central heating systems and primary circuits
Commercial hot water supply and distribution pipework
Chilled water flow and return in commercial HVAC systems
Heat pump flow and return pipework
District heating connections and secondary circuits
Frost protection on exposed or unheated pipework

How to Measure Pipe Insulation

Pipe insulation is sized by the outside diameter (OD) of the pipe. For standard UK copper pipe, 28mm refers to 28mm OD. Always measure the outside of the pipe before ordering.