Pipe Insulation

Pipe insulation, often referred to as pipe lagging in the UK, is one of the most effective ways to reduce heat loss, prevent frozen pipes, control condensation and improve the energy efficiency of heating, chilled water and refrigeration systems. Whether you're insulating domestic water pipe insulation or specifying products for a commercial HVAC installation, choosing the correct insulation material and wall thickness is essential.

At Pipelagging, we supply one of the UK's most comprehensive ranges of pipe insulation, including Armaflex elastomeric foam, Rockwool mineral wool, Kingspan Kooltherm phenolic insulation and polyethylene foam solutions. Available in sizes from 15mm to 273mm bore, our range covers heating, hot water, chilled water, refrigeration and industrial pipework. We are authorised UK distributors for all brands we stock — every product is genuine manufacturer stock, supplied with full technical data sheets and compliance documentation.

Whether you're looking for foam pipe insulation for domestic plumbing, closed-cell insulation for chilled water systems or high-temperature mineral wool for commercial plant rooms, our range covers virtually every common pipe insulation application in the UK.

With over 20 years supplying insulation products to HVAC contractors, plumbers, mechanical engineers and facilities teams throughout the UK, our technical team can help you select the correct insulation for almost any application.

Types of Pipe Insulation

Elastomeric Foam Pipe Insulation — Flexible closed-cell nitrile rubber foam including Armaflex and K-Flex. The most popular choice for domestic and commercial pipework. Excellent thermal performance, vapour resistance and flexibility. Available in self-seal and standard versions. Class O fire rated.
Mineral Wool Pipe Insulation — Rockwool Rocklap and glass wool pipe sections for high-temperature pipework including steam, hot water and industrial process pipes. Non-combustible (Euroclass A1), suitable for applications where fire resistance is critical.
Phenolic Pipe Insulation — Kingspan Kooltherm and Supaphen rigid foil-faced pipe sections offering the lowest thermal conductivity of any pipe insulation. Ideal for chilled water, district heating and applications where insulation thickness must be minimised.
Self-Seal Pipe Insulation — Pre-slit pipe insulation with a factory-applied self-adhesive closure. No tape or adhesive required. The fastest and easiest pipe insulation to install — ideal for retrofit and maintenance work.
Outdoor & UV-Resistant Pipe Insulation — Armaflex HT and specialist products for external pipework exposed to UV, weathering and high temperatures. Suitable for solar thermal, heat pump and outdoor HVAC pipework.

Foam Pipe Insulation

Foam pipe insulation is the most widely used category of pipe insulation in the UK, covering both elastomeric foam and polyethylene foam products. The two main types serve different applications:

Elastomeric foam (Armaflex, K-Flex) — Closed-cell nitrile rubber foam with a very low thermal conductivity and high vapour resistance. The standard choice for chilled water, refrigeration, domestic hot and cold water, and HVAC pipework. Its closed-cell structure prevents moisture ingress, making it particularly effective in condensation-critical applications where mineral wool would absorb moisture and lose performance. Available in Class O fire-rated grades.
Polyethylene foam (Tubolit) — A cost-effective, lightweight foam insulation for domestic heating and hot water pipework. Tubolit is widely used by plumbers and heating engineers for standard domestic applications where the high vapour resistance of elastomeric foam is not required. Easy to cut and install, available in split and self-seal versions.

For condensation-critical systems — chilled water, refrigeration, cold water services — elastomeric foam is always the preferred choice over mineral wool, as its closed-cell structure provides the vapour barrier needed to prevent condensation forming within the insulation.

How to Choose the Right Pipe Insulation

The right pipe insulation depends on four factors: pipe temperature, application environment, required thermal performance, and compliance requirements. Use the table below as a starting point.

Application	Recommended Type	Key Products	Temp Range
Domestic hot & cold water (Part L)	Elastomeric foam	Armaflex Class O, K-Flex ST	-50°C to +105°C
Commercial HVAC / chilled water	Elastomeric foam or phenolic	Armaflex, Kingspan Kooltherm	-50°C to +110°C
Refrigeration pipework	Elastomeric foam (closed-cell)	Armaflex AF, K-Flex Evo	-50°C to +105°C
Steam & high-temperature process	Mineral wool	Rockwool Rocklap	Up to +750°C
District heating	Phenolic or mineral wool	Kingspan Kooltherm, Rockwool	Up to +120°C
Outdoor / exposed pipework	UV-resistant elastomeric	Armaflex HT, K-Flex Solar	-50°C to +150°C
Condensation control	Closed-cell elastomeric	Armaflex, K-Flex	-50°C to +105°C

Not sure which product is right for your project? Call our technical team on 0161 775 1190 (Mon–Fri 8am–4pm) or use our online enquiry form.

For detailed guidance on selecting the correct wall thickness for your application, see our Pipe Insulation Wall Thickness Guide and BS 5422 Pipe Insulation Standards Guide.

Shop by Application

Outdoor Pipe Insulation — UV and weather-resistant products for external pipework
Refrigeration Pipe Insulation — Closed-cell foam for refrigerant and chilled pipework
Condensation Control Pipe Insulation — High vapour resistance for cold pipework
Foam Pipe Insulation — Elastomeric and polyethylene foam for domestic and commercial use

Shop by Brand

Armaflex Pipe Insulation — The world's leading elastomeric foam insulation brand
Rockwool Pipe Insulation — Non-combustible mineral wool for high-temperature applications
Kingspan Kooltherm Pipe Insulation — Ultra-low lambda phenolic pipe sections
Armacell Pipe Insulation — Full Armacell product range including Armaflex and Tubolit

Shop by Pipe Size

We stock pipe insulation for all standard copper and steel pipe sizes from 15mm to 273mm bore. Not sure which size you need? See our Copper Pipe Sizes Guide for help matching pipe OD to insulation bore size.

Knowledge Hub — Pipe Insulation Guides

Our Knowledge Hub contains in-depth technical guides to help you specify, size and install pipe insulation correctly.

The Ultimate Guide to Pipe Lagging — Everything you need to know about pipe insulation materials, applications and installation
BS 5422 Pipe Insulation Standards Guide — How to use BS 5422 to specify insulation thickness for UK projects
Pipe Insulation Wall Thickness Guide — Choosing the right wall thickness for your application
Copper Pipe Sizes Explained — OD, nominal bore and insulation sizing guide
Condensation on Pipes — Causes, prevention and the right insulation
Outdoor Pipe Insulation Guide — Can pipe insulation be used outside?
Armaflex vs Rockwool — Which pipe insulation should you choose?
Armaflex vs K-Flex — Comparing the two leading elastomeric foam brands
15mm Pipe Insulation Guide
22mm Pipe Insulation Guide
28mm Pipe Insulation Guide
35mm Pipe Insulation Guide
42mm Pipe Insulation Guide
54mm Pipe Insulation Guide
76mm Pipe Insulation Guide

Compliance & Standards

Pipe insulation specified and installed in the UK must comply with a range of building regulations and industry standards. Our products support compliance with:

Part L (Building Regulations) — Conservation of fuel and power; minimum insulation thicknesses for hot and cold water services
BS 5422 — Method for specifying thermal insulating materials for pipes, tanks, vessels, ductwork and equipment
CIBSE Guide C — Reference data for mechanical services design including pipe insulation thickness tables
BREEAM — Insulation product selection can contribute to BREEAM credits for energy efficiency

Our technical team can advise on thickness calculations and product selection to meet your specific compliance requirements.

Frequently Asked Questions

What is the best pipe insulation for domestic hot and cold water pipes?

Elastomeric foam pipe insulation such as Armaflex Class O or K-Flex ST is the most widely used product for domestic hot and cold water services. It meets Part L requirements, is easy to install, and provides excellent thermal performance and vapour resistance. For Part L compliance, the required insulation thickness depends on pipe size and location — our technical team can advise.

What thickness of pipe insulation do I need?

Required thickness depends on the pipe size, fluid temperature, ambient conditions, and the standard you are complying with. Part L specifies minimum thicknesses for domestic services; BS 5422 and CIBSE Guide C provide thickness tables for commercial and industrial applications. As a general guide, 25mm wall thickness is commonly specified for 15mm–28mm domestic pipework. See our Wall Thickness Guide or contact our technical team for a project-specific recommendation.

What is the difference between elastomeric and phenolic pipe insulation?

Elastomeric foam (e.g. Armaflex) is flexible, easy to install, and suitable for a wide temperature range with good vapour resistance. Phenolic pipe insulation (e.g. Kingspan Kooltherm) is rigid with a significantly lower thermal conductivity, meaning thinner sections achieve the same thermal performance. Phenolic is preferred where space is limited or very high thermal efficiency is required.

Can pipe insulation be used outdoors?

Standard elastomeric foam pipe insulation is not UV-resistant and will degrade if left exposed outdoors. For external pipework, you need a UV-resistant product such as Armaflex HT or K-Flex Solar, or standard insulation protected with an aluminium or PVC cladding system. See our outdoor pipe insulation collection for suitable products, and our Outdoor Pipe Insulation Guide for full guidance.

What pipe insulation is suitable for refrigeration pipework?

Closed-cell elastomeric foam insulation is the standard choice for refrigeration pipework. It provides the high vapour resistance needed to prevent condensation on cold suction lines. Armaflex AF and K-Flex Evo are the most commonly specified products. See our refrigeration pipe insulation collection.

Is pipe insulation fire rated?

Fire rating varies by product type. Elastomeric foam such as Armaflex Class O meets Class O surface spread of flame requirements under BS 476. Mineral wool (e.g. Rockwool Rocklap) is non-combustible and achieves Euroclass A1. Phenolic pipe insulation achieves Class O. Always check the product data sheet for the specific fire classification required by your project specification.

Do you supply pipe insulation for all pipe sizes?

Yes — we stock pipe insulation for all standard copper and steel pipe sizes from 15mm to 273mm bore, in a range of wall thicknesses. If you need an unusual size or a large quantity, contact our team for availability and pricing.

What is self-seal pipe insulation?

Self-seal pipe insulation is pre-slit along its length with a factory-applied self-adhesive closure strip. To install, open the slit, place it around the pipe, and press the adhesive strip closed — no separate tape or adhesive is required. It is significantly faster to install than standard pipe insulation and is ideal for retrofit, maintenance and domestic plumbing work.

How do I calculate how much pipe insulation I need?

Pipe insulation is sold by the metre or in standard lengths (typically 1m or 2m). Measure the total length of pipework to be insulated and add 10–15% for waste and fittings. Account for bends, valves and other fittings, which require additional material or pre-formed fitting covers. Our team can help with take-offs for larger projects.

Do you offer technical support for pipe insulation specification?

Yes — our technical team can advise on product selection, insulation thickness calculations, compliance with Part L, BS 5422 and CIBSE Guide C, and system design. Call 0161 775 1190 (Mon–Fri 8am–4pm) or use our online enquiry form.