Rockwool Rocklap Foil Backed Pipe Insulation Lagging – 1m

ROCKWOOL RockLap H&V Pipe Sections

ROCKWOOL RockLap H&V Pipe Sections are pre-formed stone wool pipe insulation sections designed for thermal and acoustic insulation of heating, ventilation and air-conditioning pipework operating from 0°C to 250°C.

Each cylindrical section is supplied pre-slit with a factory-applied reinforced aluminium foil facing and integral self-adhesive lap, providing a professional finish while making installation around existing pipework quicker and easier.

Why Choose ROCKWOOL RockLap?

• Euroclass A2-s1,d0 reaction to fire classification in accordance with EN 13501-1:2018
• 0°C to 250°C service temperature for heating, HVAC and building-services pipework
• Stone wool construction providing thermal, acoustic and fire performance
• Reinforced aluminium foil facing with integral self-adhesive lap
• Pre-slit cylindrical sections for straightforward installation around pipework
• BS 5422:2023 – can be used to satisfy the UK method for specifying thermal insulating materials for pipes, tanks, vessels, ductwork and equipment
• CE marked to EN 14303:2015
• Conforms to BS 3958-4:1982 for bonded preformed stone wool pipe sections
• Indoor Air Comfort Gold certified – Certificate IACG-377-01-02A-2025

Fire Performance

RockLap H&V Pipe Sections achieve a Euroclass A2-s1,d0 reaction to fire classification in accordance with EN 13501-1:2018.

The system has also been tested to BS EN 1366-3:2012+A1:2024 for the fire resistance of penetration seals. In suitable tested applications, RockLap H&V Pipe Sections can provide up to EI 120 – 120 minutes of fire resistance integrity and insulation.

Fire-resistance performance is application-dependent and should be specified in accordance with the relevant ROCKWOOL fire-stopping details.

Thermal Performance

RockLap H&V is designed for pipework operating between 0°C and 250°C. To maintain the bond strength of the foil facing, the insulation thickness should be selected so that the outer surface temperature does not exceed 80°C.

The applicable thermal conductivity curve depends on the pipe-section size. Refer to the ROCKWOOL Declaration of Performance when carrying out specification calculations.

Suitable Applications

RockLap H&V Pipe Sections are suitable for insulating heating, ventilation and air-conditioning pipework, including applications where thermal performance, acoustic control and fire performance are important.

ROCKWOOL has also tested RockLap H&V for applications where steel and copper pipes penetrate fire-resistant walls and floors. The tested arrangement can allow the pipe insulation to continue through the separating element rather than requiring the insulation to be locally removed or replaced.

• Commercial heating mains and primary circuits
• Steam pipework and high-temperature process pipework
• HVAC and building services pipework
• Plant room and boiler house pipework
• Industrial process pipework
• Fire-rated pipework penetrations and compartmentation

Moisture & Durability

ROCKWOOL stone wool is water repellent and non-hygroscopic, so it does not absorb water from the surrounding environment. It is also vapour permeable and retains its thermal performance in humid conditions.

ROCKWOOL reports testing of stone wool recovered from older buildings showing retention of thermal, mechanical and fire-resistance characteristics for at least 50 years, with a 65-year-old sample tested in 2023 showing no deterioration in these characteristics.

Wall Thickness Selection Guide

The appropriate insulation thickness depends on pipe diameter, operating temperature, thermal conductivity and the applicable project specification. Use the guidance below as a starting point and refer to BS 5422:2023 for specification-grade thickness selection.

• 20mm wall — Light commercial heating and hot water pipework, frost protection
• 25mm wall — Standard commercial heating applications; verify against BS 5422 for specification projects
• 30mm wall — Enhanced performance for higher-temperature heating mains and steam pipework
• 40mm wall — Industrial process pipework and high-temperature steam systems
• 50mm wall — Demanding industrial and process applications requiring maximum thermal performance
• 60–70mm wall — High-temperature industrial pipework requiring substantial insulation thickness

Shop by Pipe Size

15mm | 22mm | 28mm | 35mm | 42mm | 48mm | 54mm | 60mm | 67mm | 76mm | 89mm | 114mm

Installation

RockLap H&V Pipe Sections are supplied pre-slit and hinged. Open the section, position it securely around the pipe, remove the protective strip from the integral self-adhesive lap and press the lap smoothly over the longitudinal joint.

All joints between adjacent pipe sections should be sealed with approved aluminium foil tape. ROCKWOOL specifies 75mm wide aluminium tape where sections abut to maintain the integrity of the vapour barrier.

Note: for cold-water and chilled-water services where condensation control is critical, consider whether a closed-cell elastomeric insulation system may be more appropriate for your application.

Complete Your Installation

• Aluminium Foil Tape — Seal butt joints and ensure a continuous vapour barrier across the full pipe run
• Rockwool Rocklap Pipe Supports Foil Faced — Matching foil-faced mineral wool pipe supports for a consistent, professional finish at pipe fixings

Technical Specification

Selecting Your Size

Select the pipe outside diameter and required insulation thickness from the available options. Insulation thickness should be selected according to operating temperature, pipe diameter, required heat-loss performance and the applicable project specification.

For BS 5422 projects, use the required specification thickness rather than choosing insulation thickness solely by pipe diameter.

Frequently Asked Questions

What temperature range is ROCKWOOL RockLap H&V suitable for?

RockLap H&V Pipe Sections are designed for pipework operating between 0°C and 250°C. ROCKWOOL also states that the selected insulation thickness should keep the outer surface temperature at no more than 80°C to maintain the bond strength of the foil facing.

What fire rating does ROCKWOOL RockLap H&V have?

RockLap H&V Pipe Sections achieve a Euroclass A2-s1,d0 reaction to fire classification in accordance with EN 13501-1:2018. In suitable tested penetration-seal applications, the system can also provide up to EI 120 fire resistance, subject to the application.

Does ROCKWOOL RockLap comply with BS 5422?

ROCKWOOL states that RockLap H&V Pipe Sections can be used to satisfy BS 5422:2023 for the specification of thermal insulation. The required insulation thickness still depends on pipe diameter, operating temperature and the project specification.

Is ROCKWOOL RockLap pre-slit?

Yes. RockLap H&V Pipe Sections are supplied pre-slit and hinged with an integral self-adhesive foil lap, making them straightforward to fit around pipework.

Do the joints need aluminium foil tape?

Yes. ROCKWOOL specifies that joints between adjacent RockLap H&V Pipe Sections should be sealed with approved 75mm aluminium foil tape to maintain the integrity of the vapour barrier.

Is ROCKWOOL RockLap suitable for chilled-water pipework?

RockLap can be used on cold services, but maintaining the vapour barrier is critical. For applications where condensation control is the primary requirement, a closed-cell elastomeric insulation system may be more suitable.

What is ROCKWOOL RockLap made from?

RockLap H&V is made from stone wool insulation with a reinforced aluminium foil facing and integral self-adhesive lap.

How do I choose the correct RockLap thickness?

Select the pipe outside diameter and insulation thickness required by your application. For specification work, use the required thickness from BS 5422:2023 or the project design rather than choosing thickness by pipe size alone.