Armaflex Self Seal Class O Insulation 28mm x 13mm

Wrapping 28mm copper or plastic, Armaflex Self Seal Class O Insulation puts a 13mm wall of closed cell foam round the pipe, closed with a self-adhesive seam. It is the step up from 22mm, used in larger houses, flats with shared plant and small commercial jobs.

Why 13mm Armaflex self seal insulation on 28mm pipe

A 13mm wall is a good all-round thickness for heating and hot water, and for stopping cold mains sweating in a warm room. Because the foam is closed cell, it holds up on chilled lines where open foam would take on water.

• Bore: 28mm
• Wall thickness: 13mm
• Overall size: about 54mm once fitted
• Length: 2m, pre-slit

Two 13mm walls plus the 28mm pipe gives roughly 54mm overall. So pick clips and sleeves for the lagged size, not the bare pipe. The full set of bores is in our pipe lagging and insulation category.

Close up the butt joints between lengths as carefully as the seam itself. A tin of Armaflex adhesive does the joints, and insulated supports help on chilled pipework.

28mm x 13mm pipe lagging from our Glasgow trade counter

Drop by Plumb Parts, 555 South Street, Glasgow G14 0QX. We open Mon-Fri 8am-5pm and Sat-Sun 8am-1pm. Online ordering is available any time.

Specification

• Brand: Armaflex
• Range: Class O Self Seal
• Material: Closed cell elastomeric foam
• Connection: Pre-slit tube with self-adhesive seam
• Sizes: 28mm bore, 13mm wall, 2m long
• Standard or approval: Class O, as named
• Suitable for: Heating, hot and cold water pipework
• Pack quantity: One 2m tube

Common Questions

What size pipe insulation do I need for 28mm pipe? Match the bore to the pipe, so 28mm copper or plastic takes this 28mm bore. The 13mm wall is a good all-round thickness for heating, hot water and cold pipes in warm rooms.

Can Armaflex pipe insulation catch fire? It is rubber foam, so it is not fireproof, but it carries a Class O rating to BS 476 Parts 6 and 7. That is why it gets specified on jobs that ask for Class O.

Can I put this insulation on PEX pipe? Yes, 28mm plastic pipe has the same outside diameter as 28mm copper, so it fits snugly. It works on copper, PEX and polybutylene alike.

What is Armaflex pipe insulation? It is closed cell nitrile rubber foam made by Armacell, with its own vapour barrier built in. It is dust free and fibre free, so it is pleasant to handle.

How do I install Armaflex self seal on 28mm pipe? Wipe the pipe clean and dry, open the slit over it, peel off the tape backing and close the seam from one end. Glue the butt joints between lengths with Armaflex adhesive, and allow about 54mm across for clips and holes.

How thick should pipe insulation be? The 13mm wall here is a good all-rounder for heated rooms. In cold lofts, voids or on chilled pipes go up to 19mm or 25mm, and if the spec or building control sets a figure, use that.

How many lengths of insulation do I need? Each length is 2m, so halve your run in metres and round up. Add a spare length or two for offcuts round bends, tees and valves.