Radflex S150 System: Download Data Sheet

Surface Expansion Joint

Developed specifically for concrete decks, this surface mounted mechanical expansion joint provides an extremely effective waterproof seal. Requiring minimal preparation and concrete installation work, the S150 facilitates fast project completion. The latest generation S150 system also creates a Traffic Calming Ramp. Designed for a variety of locations, including multi-storey car parks, service roads and ramps, this durable system is equally applicable to new work and refurbishment projects. Ideally suited for use with waterproof traffic deck coating systems.

S150-3DDouble Laminated Waterproof Membrane

The S150 system features the double laminated Radflex 125 waterproof membrane bonded to the concrete, which links the waterproofing on each side of the joint gap.  The membrane is then protected by a rubber extrusion and metal reinforced rubber nosings anchored through the Radflex 125 into the concrete deck with chemical fixings.

The butyl rubber compound formulation of Radflex 125 is tough, weatherproof and flexible for a permanent waterproof layer beneath the joint. It is used in conjunction with Radflex epoxy adhesives designed for a long-lasting seal between the Radflex membrane and the substrate. Our extrusion and nosings are based on specially formulated EPDM rubber compound which has exceptional weathering properties and good flexibility over a wide temperature range. The combined elements ensure a continuous watertight finish throughout the structure.


Concrete surfaces must be float finished, abraded to remove laitence and provide good bonding surface. If the concrete surface is unsound, make good with polymer modified mortar, in accordance with manufacturers’ instructions. The concrete shoulders must be smooth and level across the expansion gap. We do not recommend application to lightweight or sand and cement screed.

Reference Installations

Radflex systems are installed in many different traffic conditions in a variety of climates. We are pleased to refer enquirers to relevant applications to confirm satisfaction with the installation and system performance.

Radflex Design Services

Advice and design services are available from our Technical Department, including reviewing requirements for particular applications, ensuring selection and installation of the most appropriate Radflex System to suit specific sites.

In standard format, the S150 system is suitable for gaps of up to 40mm at mid temperature. It accommodates rotational and vertical movement of 6mm and provides lateral flexibility up to 50mm in a completely watertight joint.


• Closed cell foam
• Polymer modified mortar haunches
• Radflex epoxy adhesive
• Radflex 125 membrane
• Chemical anchors
• EPDM extrusion
• S150 EPDM nosings (1.83 m lengths)
• Sealants
• Bolt hole caps

Materials Performance

The component parts of the system are non-degradable, unaffected by UV light or ozone and completely impervious to water or water vapour. Once installed, the waterproof membrane is completely protected by the extrusion, ensuring a long-lasting, effective surface expansion joint. Robust materials, straightforward installation and proven high performance together meet the exacting standards of the modern construction industry.

Health and Safety

Installation and use causes no ‘health and safety at work’ hazards, provided that manufacturers’ instructions are followed regarding adhesives, sealants and chemical fixings.

New & Remedial Applications

Practical, watertight surface joints are easily achieved with the S150 system, additionally functioning as speed control ramps. In remedial situations, Radflex S150 has the benefit of simple concrete preparation – fixing the membrane and nosings –  obviating the extensive preparation normally required for rebating mechanical expansion joints.

Technical Specification

Radflex S150 movement joint including Radflex 125 DLM x __mm wide, nosings, extrusion, polymer modified haunches __mm wide x __mm deep, adhesives, fixings and sealants.
Supplied and installed by Radflex Contract Services Ltd.
(Tel: 01322 276363 / 0191 417 6677).


Radflex is a registered trade mark. The Radflex 125 system is the subject of UK Patent 1288314. All reasonable care has been exercised in preparing this data sheet, which to the best of our knowledge is true and accurate.  Due to our programme of continuous improvement, the specification may be subject to updating.