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SJS: SeismicJoint System

The SJS Seismic Joint System is a Watertight, Sound-Dampened Seismic and Large-Gap Joint System For Parking Decks, Car Parks, Stadiums and Floors.

The SJS System is comprised of silicone-and-impregnated-foam hybrid components that ensure watertightness, absorb sound, dampen vibration and offer uncomplicated installation.

Key Features
  • Joint Sizes: For mean-temperature, structural-slab, joint sizes from 100mm up to 450mm (for special conditions or other sizes consult Allco). 
  • Movement Capability: 100% (+/-50%) of nominal material size.
  • Coverplates: Standard coverplate is 10mm (3/8-inch) shot-blasted aluminum or stainless steel. Other custom metals are available. Coverplate thicknesses can be customized to suit load and traffic expectations. Coverplate edge-chamfer available in standard or optional lowslope configurations (for customised options please consult Allco).
  • Fire Rating: SJS-FR1 & SJS-FR2 are designed for use in fire-rated applications. 
Scope of Use
  • For new construction and retrofit of old or failed joint systems.
  • For restoring watertightness to chronic leaking over occupied spaces.
  • Uniquely suited to joint openings designed for seismic separation of structural building elements.


  • Parking decks
  • Airport roadways
  • Shopping centre bridge connectors
  • Stadium concourses
  • Stadium treads and risers
  • Note: for split-slab, plaza and podium decks see SJS-FP.
Other Performance Attributes
  • Fire Rating: SJS-FR1 & SJS-FR2 are designed for use in fire-rated applications. They have all the performance advantages of SJS with the addition of built in, UL-Certified, 1 or 2 hour fire rating respectively. 
  • Watertight – The tensionless silicone bellows are installed flush to the mounting height of the system and just below the cover plate ensuring watertightness at the traffic surface. This eliminates the need for ineffective moisture barriers and secondary gutter systems. 
  • Sound Dampened – The flanking impregnated foam and silicone hybrid, dampens sound and shock effectively. When installed over EMCRETE, the result is arguably the quietest watertight cover plate system available.
  • Installs Rapidly – Using non-invasive anchoring SJS eliminates drilling associated with hard metal-to-concrete connections as well as intrusive pins, anchors, screws, bolts or tracks, trays or rails. The system is locked to the joint faces by the backpressure of the foam and an epoxy adhesive, and by the weight of the assembly.
  • Self-Locking, Vibration-Dampened Screws – SJS by EMSEAL minimizes vibration through the dampening action of the massive and continuous springs of impregnated foam along the entire length of the joint.
  • Field-Adjustable Plate Support – SJS is installed over a leveling-bed of EMCRETE material providing the ability to fine-tune the support of cover plate sections. This eliminates plate rocking and noise caused by unleveled plates.
  • Continuity of Seal – All EMSEAL expansion joint systems feature continuity of seal through changes in plane and direction – an essential performance differentiator.
Product Assurance
Data Sheet
Other Literature
Product Page on Supplier Website
Installation Details
SJS Installation Instructions

Allco Waterproofing Solutions specialise in quality waterproofing products and seismic joints supplying Volclay, Casali, Hydrotech and Emseal.

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