Pipe Lagging & Pipe Insulation
Pipe lagging (pipe insulation) reduces heat loss, helps protect against freezing, and controls condensation across heating, plumbing, HVAC and refrigeration systems. We supply a full range of indoor and outdoor insulation materials for domestic and commercial applications.
Pipe lagging is another term for pipe insulation, used to reduce heat loss, protect against freezing, and control condensation on pipework.
Pipe Insulation and Lagging Categories
Kooltherm Phenolic FoamKingspan phenolic foam insulation offering exceptional thermal performance for HVAC and industrial systems.
Knauf Rock FibreDurable rock mineral wool insulation ideal for high‑temperature and acoustic pipework applications.
Isopipe Plastic CoatedUV‑resistant plastic coated insulation designed for ASHP & outdoor pipework and long‑term weather protection.
K‑Flex Nitrile RubberFlexible closed‑cell nitrile rubber insulation offering excellent moisture resistance and thermal efficiency.
Armaflex EVO Nitrile RubberAdvanced nitrile rubber insulation with enhanced fire performance and long‑term energy savings.
Tubolit PolyethyleneLightweight polyethylene insulation ideal for domestic pipework and condensation control.
HT/Armaflex High TemperatureHigh‑temperature EPDM Rubber insulation designed for solar, industrial and high‑heat applications.
Climaflex PolyethyleneCost‑effective polyethylene insulation suitable for copper and plastic pipework in domestic systems.
VaporFas Adhesive JacketingPremium vapour‑barrier jacketing for protecting external insulation systems from moisture ingress.
ProClad Adhesive JacketingDurable multi‑layer jacketing system offering robust weather and impact protection.
K‑Stop Fire ProtectionFire‑rated insulation components designed to maintain fire integrity around pipe penetrations.
Morgan Thermal CeramicsHigh‑temperature ceramic fibre insulation for industrial and specialist ductwork applications.
Temati SA30 Foil TapeHigh‑performance foil tape for sealing insulation systems and vapour‑barrier applications.
Valve Insulation JacketsRemovable insulation jackets designed for valves, flanges and irregular pipework components.
Plysolene PIBWeatherproof PIB sheeting ideal for external cladding of insulated pipework systems.
Multi‑Layer Acoustic LaggingHigh‑density acoustic lagging designed to reduce noise transmission from pipework and ducting.
What Is Pipe Lagging?
Pipe lagging is another term for pipe insulation. It refers to materials fitted around pipework to reduce heat loss, help protect against freezing, and control condensation.
Types of Pipe Insulation
Different applications require different types of pipe insulation. The right material depends on temperature, environment, fire performance requirements and whether the pipework is indoors or outdoors. Below is a quick guide to the most common insulation types and where they are typically used.
Expanded Nitrile Butadiene Rubber (Flexible Foam)
Nitrile Rubber (or fully Expanded Nitrile Butadiene Rubber) such as K‑FLEX ST and Armaflex EVO is widely used on HVAC, refrigeration and chilled water systems. It offers excellent vapour resistance, flexibility and condensation control, making it ideal for preventing moisture build‑up on cold pipes.
Phenolic Foam (High‑Performance Rigid Insulation)
Phenolic insulation such as Kingspan Kooltherm provides the best thermal performance of any commonly used pipe insulation. It is typically used on heating, hot water and low‑temperature systems where maximum energy efficiency is required.
Mineral Wool Pipe Sections (Rock Fibre)
Mineral wool pipe insulation such as Knauf Rock Fibre is used on mechanical services, high‑temperature pipework and applications requiring strong fire performance. It offers excellent thermal efficiency and is suitable for both commercial and industrial systems.
Polyethylene (PE) Pipe Insulation
Lightweight polyethylene insulation such as Tubolit is commonly used for domestic plumbing, central heating and general hot and cold water services. It is easy to install and provides reliable thermal protection for everyday applications.
Outdoor & Weather‑Resistant Pipe Insulation
External pipework, including air source heat pump (ASHP) systems, requires insulation with UV‑resistant and weatherproof jackets. Products such as ISOPIPE ASHP insulation are designed specifically for outdoor environments and protect against UV, rain and temperature fluctuations.
BS 5422 and Pipe Insulation Thickness
BS 5422 is the recognised UK standard for determining the correct thickness of thermal insulation on pipework and ductwork. It takes into account operating temperature, pipe size, location, insulation material and energy performance requirements. The aim is to ensure that systems are insulated safely and efficiently, without under‑ or over‑specifying insulation.
Because BS 5422 is a detailed and technical document, there is no single “one size fits all” thickness chart that applies to every project. The correct insulation thickness depends on the specific application, including whether the pipework is carrying hot or cold fluids, whether it is located indoors or outdoors, and what level of energy performance or condensation control is required.
To make this easier, we have a number of compliance guides which summarise the key tables and provides practical guidance for common heating, hot water and chilled water applications:
Compliance Guides:
Knauf BS5422 GuideK Flex 5422 & Part L GuideKooltherm BS5422 BulletinIf you are unsure which insulation thickness you need for a particular project, please contact us with details of the pipe size, operating temperature and application. Our team can help you interpret BS 5422 and recommend suitable products such as K‑FLEX ST, Kooltherm or Knauf Rock Fibre to meet your performance requirements.
Outdoor Pipe Insulation for ASHP
Outdoor pipework requires insulation that can withstand weather exposure, UV radiation and temperature changes. Standard indoor materials such as painted polyethylene are commonly used in the UK, but they offer limited long‑term durability when exposed to sunlight, moisture and mechanical wear. This is particularly important for air source heat pump (ASHP) systems, where exposed flow and return pipework must be protected to maintain efficiency and prevent heat loss.
ISOPIPE ASHP insulation uses a different construction to typical painted PE products. It combines a flexible elastomeric insulation core with a tough polyolefin weather jacket, providing significantly better UV resistance, moisture protection and mechanical durability. This makes it a reliable choice for external pipework that needs to perform year‑round in outdoor environments.
For further guidance on insulating ASHP systems, including recommended materials, installation considerations and weatherproofing requirements, see our Outdoor Pipe Insulation & ASHP Guide.
Because ASHP pipework operates year‑round and is exposed to rain, frost and direct sunlight, long‑term durability is critical. Plastic coated systems maintain their thermal performance because they do not need recoating, whereas painted polyethylene can harden, crack or lose its protective coating after prolonged exposure. Using a purpose‑designed outdoor insulation system helps prevent heat loss, protects against weather damage and reduces the need for maintenance or replacement.
Guides
Complete Guide To Pipe Insulation
Nitrile Rubber Pipe Insulation
Knauf Technical Product Overvie w
Acoustic Insulation Technical Overview
Isopipe Heat Pump Insulation Guide
Downloads
Product Guide:
AIM Product GuideData Sheets:
AF Armaflex EvoClimaflex CE Data SheetHT ArmaflexK Flex ST SKKnauf Thermo-tek PS ProKnauf DuctwrapTubolit DGMore about Pipe Insulation
Pipe insulation and lagging is a thermal barrier placed around hot and cold water pipes. It is made from materials such as polyethylene foam, nitrile rubber, phenolic foam or mineral wool, all designed to keep heat where it belongs.
For hot pipes, insulation reduces wasted energy, while for cold pipes, it prevents condensation and freezing during colder months. By adding insulation, households and businesses can cut heating costs, extend the life of pipework, and avoid costly repairs from burst or damaged pipes.
Benefits of Pipe Lagging
Pipe lagging is more than just a covering. It plays an essential role in keeping homes and businesses running smoothly throughout the year, especially during harsh British winters. When temperatures drop, uninsulated pipes can freeze and burst, causing expensive damage. Insulation creates a protective barrier that reduces this risk and has other benefits too, which we have detailed below:
Energy Savings
Insulated pipes retain more heat, so boilers and heating systems use less energy. This reduces heating bills and quickly offsets the cost of installation. Pipe insulation also allows for consistent temperatures, meaning you won't need to adjust your central heating as often to stay cosy.
Winter Protection
British winters are unpredictable, and exposed pipes in lofts, garages, and outdoor spaces are vulnerable. Outdoor pipe insulation helps prevent freezing, offering peace of mind during cold snaps.
Condensation Control
Cold water pipes without lagging often attract condensation, which can lead to damp and mould. The right closed-cell pipe insulation acts as a barrier, protecting surfaces and pipework.
Noise Reduction
Acoustic lagging reduces the sound of water rushing through pipes, a simple way to create a quieter home or workplace.
Simple Installation
Most insulation is pre-slit and slides over pipework easily. It can be cut to size and secured with K-Flex Tape, making it a quick DIY project or a time-saver for professionals.
Buy Pipe Insulation UK
If you are looking to buy pipe insulation in the UK, you will find a wide choice of sizes and materials to suit different pipe diameters and applications. Whether insulating central heating pipes, outdoor pipework, or plumbing in loft spaces, there are options available for every requirement.
As trusted pipe insulation suppliers, we stock a full range of products that are durable, easy to fit, and compliant with UK standards. Ordering online is simple, with fast delivery to homes and businesses nationwide.
Choosing the Right Pipe Insulation
Polyethylene Foam
Polyethylene pipe insulation is lightweight and cost-effective, ideal for domestic pipework.
Nitrile Rubber
Nitrile rubber insulation is moisture-resistant and suitable for hot or cold use.
Mineral Wool
This can be either glass mineral wool or rock mineral wool insulation. Both offer high thermal performance with excellent fire resistance.
Phenolic Foam
Phenolic foam pipe insulation is an ultra high performance material with thermal conductivities as low as 0.025 W/m·K. Supplied foil-faced in 1m lengths.
Outdoor Pipe Insulation
Outdoor pipe insulation is one of the most misunderstood applications of all; a product can be closed cell but this does not mean waterproof, only water resistant. There is also the issue of UV stability — the majority of materials are not suitable for outdoor use without additional coatings. Plastic-coated outdoor insulation can be used outdoors long term without any additional protection.
Installation and Maintenance
Installing pipe insulation is straightforward. Pre-slit lengths simply slide onto pipes, and joints can be secured with K-Flex Tape.
Once fitted, insulation requires little maintenance. Regular checks ensure it remains intact, and any damaged sections should be replaced promptly to maintain performance.
Get Quality Pipe Insulation from Trusted UK Suppliers
At Advanced Insulation Materials Ltd, we make it easy to buy pipe insulation in the UK with confidence. As established suppliers, we offer a wide range of products designed to improve energy efficiency and protect pipework from the challenges of winter.
We source from trusted manufacturers to guarantee quality and durability. From everyday foam lagging to specialist insulation, we provide solutions for every project.
When you choose us, you’ll benefit from:
- Competitive prices on a full range of products and pipe insulation accessories
- Expert advice on selecting the right materials
- Fast UK-wide delivery
- Additional options such as loft insulation and passive fire protection
Whether you want to cut energy bills, protect against winter damage, or extend the life of your plumbing, our team is here to help. Order online today and get high-quality pipe insulation delivered straight to your door.