SJS-Seismic Joint System

Seismic Expansion Joint System - Watertight, Sound-Dampened for Parking Decks, Car Parks, Stadiums, Floors

A seismic expansion joint, the SJS System is watertight and features a trafficable cover plate that is not attached to the concrete deck. It is comprised of silicone-and-impregnated-foam hybrid components that ensure watertightness, absorb sound, dampen vibration and offer uncomplicated installation. Specify SJS-FR for all the benefits of SJS with the added life safety assurance of a built-in UL 2079 fire rating.

SJS is constructed from two precompressed hybrid foam sealants pre-assembled in parallel adjacent to a heavy-duty extruded spline. The spline acts as a receptor for attaching the surface-mounted traffic plates that bear vehicle and other loads. The result is a system that offers features and benefits not found in alternative products intended for large, horizontal structural joint gaps.

Unlike side-mounted coverplates, the SJS plate is not anchored into the concrete and will not loosen during load transfer and vertical deflection movement.

Watertight at the deck surface, the SJS System does not rely on gutters that hang under the joint. Water is thus not trapped where it must be managed away.

SJS-Seismic Joint System

Seismic Expansion Joint System - Watertight, Sound-Dampened for Parking Decks, Car Parks, Stadiums, Floors

SJS System is a traffic-durable, non-invasively-anchored, watertight seismic expansion joint cover system

SJS-FR fire rating built in to Seismic Joint System

SJS-FR and SJS for joints under 4-inches

Hudson Yards, NYC, SJS from Emseal in plaza deck pavers

Unobtrusive, Quiet, Watertight, Trafficable Coverplate with No Invasive Anchors– SJS SYSTEM at Boston Prudential Center Parking Entrance

In the bowl, with the seats installed, the expansion joints become almost unnoticeable.

After 6 years of service, featuring aluminum coverplates (stainless steel is an option), with an ADA compliant coefficient of friction, this SJS SYSTEM is watertight, quiet, traffic durable, non-invasively anchored and aesthetically coordinated.

CA 49ers Interior Floor expansion joint bathroom SJS System EMSEAL

Finished installation of SJS Seismic Joint System at New York Mets CitiField.

EMSEAL's SJS Seismic Joint System installed on the Venetian Pool deck.

Where fire ratings are required the EMSHIELD SJS-FR1 and EMSHIELD SJS-FR2 were and will be used.

Airport expansion joints - Whether for exterior arrivals and departures sidewalks, or interior terminal applications, the SJS was selected for this project because it is watertight, fire-rated, insulating, sound-absorbing and because it can handle large structural movements.

Airport expansion joints - Installation of SJS Seismic Joint System at El Dorado Airprot Bogota Colombia

This is a view looking down the completed installation of the SJS SYSTEM in the seating bowl. The sandblasted coverplates are skid resistant and feature a long chamfer on its edges to facilitate pedestrian traffic.

The SJS SYSTEM is unobtrusive and the long-bevel, flint-blasted coverplates provide an accommodating walking surface.

Despite 18-inch wide stainless steel cover plates, the finished product in the bowl is nearly unnoticeable to the casual observer.

Factory-fabricated Custom-90 tread/riser assemblies are made to field measurements for each step. Precompressed to less than the joint size, the SJS sits ready for installation into supplied epoxy on the joint faces.

Before installation of the cover plates, an injected sealant band of supplied silicone seals substrate voids and locks the silicone bellows to the substates

Ensuring substrates are in plane across the joint. The Emcrete nosing material is easily adjusted to ensure the plates sit completely flat.

Continuity of seal from top of stadium to bottom of each seating level is assured with factory-fabricated SJS sections. Plates are seen at right ready for installation

Attaching vertical riser cover plates. A factory-installed custom extrusion makes the transition between the tread and riser plates

As with any construction product, the useful life of the material can be maximized with routine inspection and repair if required. Clearing of surface debris and inspection will reveal any damage to the product or adjacent substrates that might affect building performance. Repair, if necessary of the system can be accomplished without removing the FP capping strips--requiring only damaged sections of the foam-and-spline-assembly to be removed and reinstalled--not the entire length of the joint as is typical of extruded-seal systems. Consult EMSEAL to discuss specific conditions. In installations subject to snow removal, the detail for recessing the system to flush with the deck should be used. Consult EMSEAL. For guidance on appropriate snow removal practice click here.

Expansion Joints: Emseal's SJS Seismic Joint System HD expansion joint cover is a watertight solution for the Natick Mall parking deck.

FL Marlins Stadium concourse expansion joints SJS System EMSEAL

Custom-made tread plates for SJS System in Levis Stadium

Seismic expansion joint cover plates blend with deck coating in bowl of Levis Stadium

Stadium Concourse Solid Slab SJS System EMSEAL

Seismic expansion joint SJS custom curb EMSEAL

Expansion joints: SJS HD features heavy duty plates, a deeper, beefed-up spline and foam assembly and more frequent cover plate screws.

Seismic Joint System non-invasivley anchored, watertight coverplate system from EMSEAL

Sika Emseal SJS expansion joint installed in the ATL Airport parking deck to accommodate structural movement.

Rental Car Center at Hartsfield-Jackson Atlanta International Airport with a newly installed SJS expansion joint system.

Close-up of finished SJS expansion joint seal with coverplate at the ATL Rental Car Center parking deck.

Close-up of the expansion joint installed through a tread-riser vertical transition at Ryan Field, showing the continuous seal as it steps from tread to riser to tread.

Expansion joint installed along a tread-and-riser run in the precast seating structure at Ryan Field.

Expansion joint terminating at the parapet wall at Ryan Field, showing the seal carried from the concrete deck up through the wall condition.

Close-up of the 90-degree vertical transition in the Ryan Field expansion joint, showing the factory-fabricated coverplate carrying the seal through the direction change without a break.

Expansion joint running from the playing field wall through the seating bowl steps at Ryan Field, showing the joint's continuous path across the transition from field level to the tread-and-riser stairway.

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SJS System is a traffic-durable, watertight, non-invasively-anchored seismic expansion joint cover system. And with SJS-FR you can have a fire rating built in.

For less than the installed cost of separate fire barrier blanket, you can have SJS with a built-in UL 2079 fire rating. Specify SJS-FR for the added life safety assurance.

SJS and SJS-FR are now available for smaller joints under 4-inches (100mm) for indoor and open air applications configured as shown above. With a built-in fire rating, Specify SJS-FR to ensure waterproofing and life safety are addressed in a single, top-side installation. (Note: Fire rating for joints under 4-inches (100mm) by Engineered Judgement)

SJS System is just one of many expansion joints from Emseal that fill, seal and bridge the structural expansion joint openings at Hudson Yards - New York City’s newest, 28-acre, mixed-use neighborhood in Manhattan.

Unobtrusive, Quiet, Watertight, Trafficable Coverplate with No Invasive Anchors at Boston's Prudential Center.

In the seating bowl of Metlife Stadium with the seats installed, the expansion joints become almost unnoticeable.

After more than 6 years of service, featuring aluminum coverplates recessed to mitigate against snow plowing, with an ADA compliant coefficient of friction, this SJS SYSTEM is watertight, quiet, traffic durable, non-invasively anchored, and aesthetically coordinated at Boston's Prudential Center.

SJS-Seismic Joint System as an interior floor expansion joint in bathrooms at the San Francisco 49ers Levi's Stadium.

Finished installation of SJS Seismic Joint System at New York Mets CitiField.

Recessed and cunningly disguised, SJS Seismic Joint System installed on the pool deck of The Venetian in Las Vegas.

Factory-installed hangar bars aide installation by holding the SJS at the required installation height. Hangar bars are removed to install the cover plates. El Dorado International Airport.

Whether for exterior arrivals and departures sidewalks, or interior terminal applications, the SJS was selected for this airport project because it is watertight, insulating, sound-absorbing and because it can handle large structural seismic movements. El Dorado International Airport.

Installation of SJS Seismic Joint System at El Dorado Airport Bogota Colombia.

Looking down the completed installation of the SJS SYSTEM in the seating bowl at VCU's Commonwealth Stadium. The sandblasted coverplates are skid resistant and feature a long chamfer on its edges to facilitate pedestrian traffic.

This is a view looking down the completed installation of the SJS SYSTEM in the seating bowl at the Meadowlands MetLife Stadium. The sandblasted coverplates are skid resistant and feature a long chamfer on its edges to facilitate pedestrian traffic.

Factory-fabricated Custom-90 tread/riser assemblies are made to field measurements for each step. Precompressed to less than the joint size, the SJS sits ready for installation into supplied epoxy on the joint faces at the Meadowlands MetLife Stadium.

Before installation of the cover plates at the Meadowlands MetLife Stadium, an injected sealant band of supplied silicone seals substrate voids and locks the silicone bellows to the substrates.

Ensuring substrates are in plane across the joint. The Emcrete nosing material is easily adjusted to ensure the plates sit completely flat at the Meadowlands MetLife Stadium.

Continuity of seal from top of stadium to bottom of each seating level is assured with factory-fabricated SJS sections. Plates are seen at right ready for installation at the Meadowlands MetLife Stadium.

Cover plate screws are self-tapped into the underlying spline channel at the Meadowlands MetLife Stadium.

Attaching vertical riser cover plates at the Meadowlands MetLife Stadium. A factory-installed custom extrusion makes the transition between the tread and riser plates.

Custom toe-kick terminations ensure continuity of seal and properly seal and protect 10-inch (250mm) structural joint openings at Metlife Stadium.

Emcrete nosing material built up on either side of SJS coverplates, projects the plates from snow plows and takes a beating from suddenly applied tire loads.

SJS-FR in Florida Marlins stadium expansion joints ensure life safety in concourses over occupied space.

Levi's Stadium chose SJS-FR with its built in UL 2079 fire rating to ensure life safety in addition to water tightness and trafficability.

At Levi's
49ers Stadium the joints were located in the corner of the stadium. This created a unique shape at both the inside and outside riser transitions for each tread plate. Custom fabricated plates were made by EMSEAL from templates made by the contractor for each and every tread on the stadium.

Sand-blasted aluminum cover plates are virtually indiscernible from the deck coating in the seating bowl of Levis Stadium even though the plates are up to 24-inches wide.

SJS watertight at the deck surface. We don't like gutters. They hide where leaks are. And they hide the damage caused by leaks. More on gutters.

What's possible? There is no condition that our Tech Team won't earnestly try to customize for you. Here the SJS follows a sloped wash next to a column. A custom cover plate covered the plane change as well.

Emcrete nosing material built up on either side of SJS coverplates, projects the plates from snow plows and takes a beating from suddenly applied tire loads.

PLEASE DON'T screw coverplate anchors into your concrete when you can use non-invasively anchored SJS from EMSEAL. One of the product development design principles of the SJS SYSTEM was to eliminate side-mounting of coverplates with anchors driven into concrete. We did this by anchoring the plate to a spline flanked by non-invasively anchored precompressed foam. The result is a quieter, more durable, and watertight coverplate expansion joint system that has benefited over 260+ venues globally.

SJS installed at the Rental Car Center at Hartsfield-Jackson International Airport in Atlanta. Emcrete self-levelling elastomeric nosing was utilized to create a level and sound-dampened substrate.

Another angle of the SJS installed at the Rental Car Center in Atlanta.

Close up finished installation of SJS and Emcrete at the ATL Rental Car Center parking deck.

Custom SJS tread & riser transitions installed at Ryan Field at Northwestern University. This view shows the watertight foam installed before the non-invasively anchored plate is attached.

Each tread & riser section is precisely measured and fabricated so each joint can be dropped into place as the run continues up the stadium bowl.

The custom fabricated plates are then non-invasively anchored into the self-tapping spline of SJS.

Custom beveled coverplates were designed to continue up the vertical run.

Once the plates are installed, the expansion joint is ready to accept a high volume of traffic that these joints are subjected to. Click to view the complete project profile at Northwestern's Ryan Field.

Features

Watertight
Traffic durable
ADA Compliant
Sound dampened
Non-invasive anchoring
No concrete-embedded coverplate anchors
No hard connections to concrete
Minimal components
Self-locating plate anchors
No gutters
Rapid installation–new or retrofit
Eliminates leaks at large structural expansion joints
Reduces maintenance costs
Built-in fire rating with Emshield SJS-FR

Sizes

2″ to 16″ | 50 – 400mm
Product Depth: varies with joint size (see CAD Library)

Movement

Up to 100% Total (+50% and -50% of nominal supplied size.)

Color

Standard cover plate is aluminum with ADA-compliant, flint-blasted finish. Stainless steel also available.
Other finishes by request — contact EMSEAL

Uses

Features Explained

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. SJS System is also available specifically for watertight integration with split-slab buried waterproofing systems–see SJS-FP.

Sound Dampened – The flanking impregnated foam and silicone hybrid dampens sound and shock effectively. When installed over EMSEAL-supplied elastomeric nosing material Emcrete, the result is arguably the quietest watertight cover plate system available. (Video: See and hear the SJS difference.)

Installs Rapidly – Using non-invasive anchoring the SJS System 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 injection of a silicone sealant band at the bellows to substrate interface. (Video of installation in a parking deck or a stadium at the New York Mets and the San Francisco 49ers).

Self-Locating Cover Plate Screws – The center spline is a continuous receptor for the cover plate screws that are self-tapped into the anchor channel. This dramatically reduces the installation-related problems of locating self-centering, sliding ball devices and pantographs. The probability of screws being left out is eliminated ensuring proper anchoring.

Self-Locking, Vibration-Dampened Screws – Vibration in systems that rely on metal-to-metal connections and contact points is the main cause of screw loosening. SJS minimizes vibration through the dampening action of the massive and continuous springs of impregnated foam along the entire length of the joint. In addition, 30 pounds of force is required to loosen the screws offering excellent screw tightness without the need for thread-lock compounds.

Field-Adjustable Plate Support – Concrete in new and retrofit applications is inevitably uneven across and along the joint. The SJS System is installed over a leveling-bed of Emcrete elastomeric nosing material providing the ability to fine-tune the support of cover plate sections. This eliminates plate rocking and noise caused by unleveled plates. Systems that attach or utilize intrusive extruded rails to receive sliding ball plate retention devices cannot be adjusted to eliminate unevenness across and down the length of the joint.

Continuity of Seal – All EMSEAL expansion joint systems feature continuity of seal through changes in plane and direction –– an essential performance differentiator. Interlocking or continuous fabricated transitions for curbs, sidewalks, treads and risers, and parapets for example, are available with the SJS System.

Finite Element Analysis (FEA) Compiled Safety Factors – Prior to field trials, the SJS System was modeled using FEA to determine the suitability of design to worst case possible parking deck loads.

Under the scenario of a 4,000 lb vehicle skidding across the joint system to full stop once past the cover plate, FEA modeling predicted lateral displacement of the cover plate of less than 3/4-inches (19mm) and safety factors in key components as follows:

FEA Safety Factors: Traffic Plate – 5; Screws – 11; Spline Pins – 10; Center Spline – 7

Extreme Conditions — SJS Seismic Joint System is designed to handle the vast majority of heavy traffic and load applications. For high-torque, extremely heavy load applications in traffic decks see SJS-HD and contact EMSEAL. For applications requiring a built-in fire rating, see SJS-FR.

Composition

The SJS System is two horizontal precompressed foam sealants pre-assembled in parallel adjacent to a heavy-duty extruded aluminum spline. The spline is designed as the receptor for the attachment of traffic plates that bear vehicle and other loads.

The silicone-and-impregnated-foam hybrid components act to anchor the system, ensure watertightness, absorb sound, and dampen vibration.

The factory-assembled foam and spline assembly is shipped with factory-attached installation hanger-bars. Epoxy gel adhesive is field-applied to the faces of the joint opening. The sealing assembly is lowered into the joint gap where it self expands into epoxy adhesive.

Consecutive lengths are joined through the field-application of manufacturer-supplied, low-modulus, high-movement silicone to the spline and intersecting bellows surfaces. Friction fit alignment pins prevent the joins from moving during silicone cure. A field-applied silicone sealant band is injected at the bellows to joint substrate interface to seal substrate voids and complete the waterproofing. The SJS joint-sealing assembly installation hanger bars are removed sequentially as coverplates are lowered over the joint and screwed to the center spline, completing the installation.

Design Considerations

Substrates must be parallel, plumb, have sufficient clear depth to receive the material specified and be capable of resisting approx. 2.5 psi backpressure from the foam.
Deck surface should be level for proper seating of coverplates.
The SJS System from EMSEAL can be installed in several ways as selected by the designer or owner:
- Surface mounted on top of concrete deck (no recess, no blockout).
- Surface mounted on top of EMSEAL elastomeric nosing material in blockouts on each side of the joint.
- Recessed on top of Emcrete elastomeric nosing material in blockouts on each side of the joint.

Transitions & Terminations

Custom-90’s
(US Patent 9,200,437; 10,066,387; 10,422,127; 10,570,611; 10,794,056)

Custom-90’s, are factory-fabricated inside and outside 90-degree transition pieces.
Custom-90’s are available when field conditions and measurements are known up front.
Custom-90’s are widely used in stadium tread and riser applications or other applications where numerous inside and outside 90-degree transitions are required. Consult EMSEAL.
SJS System is highly configurable. Transitions at curbs, parapets, toe-kicks and between dissimilar joint systems can be properly sealed with assemblies factory-fabricated to match field measurements.

Maintenance

As with any construction product, the useful life of the material can be maximized with routine inspection and repair if required.
Clearing of surface debris and inspection will reveal any damage to the product or adjacent substrates that might affect building performance.
Repair, if necessary of the system can be accomplished by removing the cover plates and replacing only damaged sections of the foam-and-spline-assembly. Consult EMSEAL to discuss specific conditions.
In installations subject to snow removal, the detail for recessing the system to flush with the deck should be used. Consult EMSEAL. For guidance on appropriate snow removal practice click here.

Availability & Price

Available for shipment internationally.
Prices are available from local distributors or representatives and/or directly from the manufacturer.
The product range is continually being updated, and accordingly EMSEAL® reserves the right to modify or withdraw any product without prior notice.

Sustainability

Environmental Product Declaration (EPD)

Sika Emseal provides a third-party verified Environmental Product Declaration (EPD) covering its precompressed foam sealants and expansion joint systems (ASTM-EPD1130, valid March 2026 – March 2031).

SJS-Seismic Joint System

Seismic Expansion Joint System - Watertight, Sound-Dampened for Parking Decks, Car Parks, Stadiums, Floors

SJS-Seismic Joint System