Foam Pipe Insulation

Foam pipe insulation is the most widely used type of pipe insulation in the UK, covering both elastomeric foam and polyethylene foam products. Lightweight, flexible and easy to install, foam pipe lagging is the first choice for domestic plumbing, central heating, chilled water, refrigeration and HVAC pipework across a wide range of applications.

At Pipelagging, we stock the UK's most comprehensive range of foam pipe insulation, including Armaflex elastomeric foam, K-Flex, and Tubolit polyethylene foam. Available in all standard pipe sizes from 15mm to 114mm bore, with a range of wall thicknesses to suit domestic and commercial applications.

Types of Foam Pipe Insulation

Type	Products	Best For	Key Advantage
Elastomeric foam	Armaflex, K-Flex	HVAC, chilled water, refrigeration, domestic	High vapour resistance, Class O fire rated
Polyethylene foam	Tubolit	Domestic heating and hot water	Cost-effective, lightweight, easy to install

Elastomeric Foam Pipe Insulation

Elastomeric foam is a closed-cell nitrile rubber foam with a very low thermal conductivity and high vapour resistance. It is the professional standard for commercial and industrial pipework, and is increasingly specified for domestic applications where performance requirements are higher than standard polyethylene foam can meet.

Key properties:

Closed-cell structure prevents moisture ingress and condensation
High vapour resistance — essential for chilled water, refrigeration and cold pipework
Class O fire rated (Armaflex Class O, K-Flex ST)
Wide temperature range: -50°C to +105°C (standard grades)
Flexible — bends around pipework without cutting or jointing
Available in self-seal versions for faster installation

Best applications: HVAC pipework, chilled water systems, refrigeration, domestic hot and cold water (Part L compliance), condensation-critical applications.

Armaflex Pipe Insulation — the world's leading elastomeric foam brand
K-Flex Pipe Insulation — high-performance elastomeric foam alternative

Polyethylene Foam Pipe Insulation

Polyethylene foam pipe insulation is a cost-effective, lightweight option for standard domestic heating and hot water applications. Tubolit is the most widely used polyethylene foam pipe insulation in the UK, available in split and self-seal versions for easy installation on new and existing pipework.

Key properties:

Lightweight and easy to handle
Simple to cut with scissors or a knife
Cost-effective — the most affordable foam pipe insulation option
Available in split and self-seal versions
Suitable for domestic hot and cold water and central heating pipework

Best applications: Domestic hot and cold water pipes, central heating flow and return, condensate pipes, pipes in lofts, garages and unheated spaces, retrofit insulation on existing pipework.

Tubolit Pipe Insulation — the UK's most popular polyethylene foam pipe insulation

Elastomeric Foam vs Polyethylene Foam — Which Should You Choose?

Feature	Elastomeric Foam (Armaflex, K-Flex)	Polyethylene Foam (Tubolit)
Thermal conductivity	Lower (better performance)	Higher (adequate for domestic)
Vapour resistance	Very high — closed cell	Moderate
Fire rating	Class O	Standard
Temperature range	-50°C to +105°C	0°C to +95°C (typical)
Condensation control	Excellent	Limited
Cost	Higher	Lower
Best for	HVAC, chilled water, refrigeration, Part L	Standard domestic heating and hot water

For condensation-critical applications — chilled water, refrigeration, cold water services — elastomeric foam is always the correct choice. Its closed-cell structure provides the vapour barrier needed to prevent condensation forming within or on the surface of the insulation. Polyethylene foam does not provide sufficient vapour resistance for these applications.

For standard domestic hot water and central heating pipework where condensation is not a concern, polyethylene foam (Tubolit) is a cost-effective and perfectly adequate solution.

Why Choose Foam Pipe Insulation?

Easy to install — split along the length, place around the pipe and secure with adhesive or self-adhesive closure
Lightweight — easy to handle and cut to length with scissors or a knife
Flexible — bends around pipework without the need for pre-formed bends or fittings in most domestic applications
Frost protection — effective protection for pipes in lofts, garages and unheated spaces
Part L compliance — elastomeric foam in appropriate wall thicknesses meets Building Regulations Part L requirements for hot and cold water services
Condensation control — closed-cell elastomeric foam prevents condensation on cold pipework

Shop by Pipe Size

We stock foam pipe insulation for all standard copper and steel pipe sizes. Not sure which size you need? See our Copper Pipe Sizes Guide.

Knowledge Hub — Foam Pipe Insulation Guides

The Ultimate Guide to Pipe Lagging — Everything you need to know about pipe insulation materials and applications
Armaflex vs K-Flex — Comparing the two leading elastomeric foam brands
Pipe Insulation Wall Thickness Guide — Choosing the right wall thickness for your application
BS 5422 Pipe Insulation Standards Guide — Compliance and thickness specification
Condensation on Pipes — Causes, prevention and the right insulation
Copper Pipe Sizes Explained — OD, nominal bore and insulation sizing guide
Pipe Insulation — Full range including mineral wool and phenolic
Outdoor Pipe Insulation — UV-resistant foam for external pipework
Refrigeration Pipe Insulation — Closed-cell foam for refrigerant and chilled pipework
Tubolit Pipe Insulation — Polyethylene foam for domestic heating and hot water

Frequently Asked Questions

What is foam pipe insulation made from?

Foam pipe insulation is made from either elastomeric foam (closed-cell nitrile rubber, such as Armaflex and K-Flex) or polyethylene foam (such as Tubolit). Elastomeric foam offers superior thermal performance and vapour resistance; polyethylene foam is a cost-effective option for standard domestic applications.

What is the difference between Armaflex and Tubolit?

Armaflex is an elastomeric foam with a very low thermal conductivity, high vapour resistance and Class O fire rating — the professional choice for HVAC, chilled water and commercial pipework. Tubolit is a polyethylene foam designed for standard domestic heating and hot water applications where the higher performance of elastomeric foam is not required. Armaflex is more expensive but significantly outperforms Tubolit in demanding applications.

Can foam pipe insulation be used on cold water pipes?

Yes, but the type matters. For cold water pipes where condensation is a risk, closed-cell elastomeric foam (Armaflex or K-Flex) is essential — its high vapour resistance prevents moisture from reaching the pipe surface. Standard polyethylene foam does not provide sufficient vapour resistance for condensation-critical cold water applications.

What wall thickness of foam pipe insulation do I need?

Required wall thickness depends on the pipe size, fluid temperature and the standard you are complying with. For domestic hot and cold water services under Part L, 25mm wall thickness is commonly specified for 15mm–28mm pipework. See our Wall Thickness Guide for full guidance.

Is foam pipe insulation self-adhesive?

Self-seal versions of both elastomeric and polyethylene foam pipe insulation are available. These have a factory-applied adhesive strip along the longitudinal slit, allowing installation without separate tape or adhesive. Standard (non-self-seal) versions require Armaflex 520 adhesive or equivalent to seal the slit and butt joints.

Can foam pipe insulation be used outdoors?

Standard foam pipe insulation is not UV-resistant and will degrade if left exposed to sunlight. For outdoor applications, use a UV-stabilised product such as Armaflex HT Solar, or protect standard insulation with a PVC or aluminium cladding system. See our outdoor pipe insulation collection for suitable products.