Watertight Expansion Joints and Construction Sealants by EMSEAL


A roof expansion joint, EMSEAL RoofJoint is a patented dual-seal, double-flanged, extruded thermoplastic rubber system for sealing expansion joints in roofs. Watertightness is achieved through positive integration with the roofing membrane and a purpose-designed system for transitioning between the joint in the roof and joints in walls.

The waterproofing element of most other roof expansion joints is a looped membrane. The loop either hangs down into the joint or is humped up by means of a foam backing. Either way, looped membranes don’t work well at the transition from the roof joint to wall joints and feature only one level of sealing.

Unique to RoofJoint is the double-level flange. This flange allows multi-layered, watertight integration with the roofing membrane. The lower flange is welded or adhered to the roof membrane brought up to the joint. A termination bar and anchors mechanically lock the flange to the roof decking or blocking. The upper flange counterflashes the termination bar and underlying membrane ensuring that penetrations made by the attachment of the termination bar are completely sealed. The upper flange is further flashed to the roofing membrane by means of the roofing manufacturers’ standard flashing tape or by over-welding a strip of roofing.

Movement at the joint is accommodated by the folding design of the gland. The double-cell configuration provides two levels of sealing. The geometric shape is purpose-designed for the lowest strain during movement to ensure longevity.



  • High movement
  • Redundant sealing
  • Double-level roof-membrane integration flanges
  • Redundant fastening—adhesion or welding & termination bar
  • Factory heat welded transitions at tees, crosses, roof-to-wall, etc.
  • Watertight transition to Seismic Colorseal wall joints using RoofJoint Closures
  • Uniquely addresses wall joint to roof joint interface
  • UV-stable
  • NPVC version available for welding compatibility with PVC membranes, as well as for adhering into asphaltic, SBS, mod-bit, or thermoset rubber roof  membranes
  • White TPV version available for direct welding into TPO reflective roof membranes
  • Can be fire-rated with installation of Emshield DFR


RJ-0200: 2-3 inches | 50-75mm
RJ-0400: 3-5 inches | 75-125mm

Larger custom sizes may be available to suit a specific application. Consult EMSEAL.


RJ-0200: 2 1/2-inches | 60mm
RJ-0400: 5-inches | 125mm

For questions regarding movement in a specific condition, consult EMSEAL.


NPVC: Black or Reflective White
TPV: Reflective White


  • Flat roofs
  • Sloped roofs
  • Green and garden roofs
  • Soft-scaped plazas
  • Roof to wall joint transitions
  • Tie in to hot rubber roofs
  • Weld to PVC roofs
  • Adhere to mod-bit roofs
  • Adhere to torch-applied roofs
  • Weld to TPO roofs

U.S. Patents

Something New From EMSEAL US Patent: 9,850,662
US Patent: 9,739,050
US Patent: 9,322,163
Patent Pending

RoofJoint is available in two formulations: Nitrile-Rubber-Plasticized NPVC alloy or TPV (Thermoplastic Vulcanizate).

Nitrile-Rubber-Plasticized NPVC
Used for:
– direct welding to PVC-based roof membranes;
– adhesion into hot or cold-applied rubberized asphalt systems;
– adhesion to thermoset-rubber roof membranes (EPDM, Neoprene, etc.)
– adhesion to SBS membranes
– adhesion into torch-applied mod-bit membranes

The PVC version of RoofJoint is extruded from a Nitrile-Rubber-Plasticized PVC alloy. A Nitrile-Rubber-Plasticized NPVC blend was chosen for this product for its broad compatibility with most roofing systems.

It can be heat-welded to PVC roofs, and subject to the recommended procedures of the particular roofing membrane manufacture in respect to preparation, cleaning, priming, etc., adheres well to the accessories of all adhered (sheet-goods), asphaltic (hot or cold applied), and SBS modified systems.

TPV (Thermoplastic Vulcanizate)
Used for direct integration through welding to TPO (Thermoplastic Olefin) based roof membranes.

As with all EMSEAL expansion joint systems, continuity of seal is extended to crosses, tees, upturns, downturns, roof-to-wall, and other compound conditions typically found in construction projects.

Factory-fabricated transition pieces can be welded to straight lengths in our plant wherever field measurements are provided and can be butt-welded to straight lengths in the field using simple equipment and training available from EMSEAL. All welds are strengthened with reinforcing strips.

Roof expansion joint solid-wall closure seals roof to wall joint interfaceSolid-Wall RoofJoint Closure
This factory-fabricated transition piece is manufactured from Seismic Colorseal wall-expansion joint material from EMSEAL. This single unit piece has factory-coated silicone bellows on the top and upper-back faces for integration with Seismic Colorseal in the wall and Horizontal Colorseal as a secondary seal and insulator across the roof.

The silicone-coated top side of the closure is shaped to match the underside of the RoofJoint extrusion. The Solid-Wall RoofJoint Closure is installed before installing the RoofJoint. It is installed ¾” down from the roof deck or wood blocking surface. A sealant band of silicone is applied across the upper mating surface of the closure. The RoofJoint is then installed. The underside of the RoofJoint will mate with the top of the already installed closure.

Roof expansion joint cavity-wall closure seals roof to wall joint interfaceCavity-Wall RoofJoint Closure
Like the solid-wall closure, the cavity-wall RoofJoint closure, is a factory-fabricated transition piece made from Seismic Colorseal. The difference is an extended, horizontal setback portion of coated foam to bridge the cavity from facade to structural backup wall. The sides of the “bridge” are additionally coated with silicone to seal them against moisture in the cavity and to constrain the lateral expansion of the foam into the cavity.

The underside of the RoofJoint marries to the top of the appropriate RoofJoint Closure. Seismic Colorseal in the wall joint is joined to the RoofJoint Closure. This creates a watertight continuity of seal from the structure’s vertical plane (wall) through the horizontal plane (roof).

RoofJoint is ideally suited for use in sealing the structural slabs beneath green, vegetative roof assemblies. Because the growing medium is loose, compressible and granular, movement that occurs at the structural slab can be absorbed without detrimental effect in the green roof overburden.  The groove in the extrusion act as a reservoir for excess growing medium moisture while not prohibiting drainage across the joint when needed.

RoofJoint is for use in roof decks, green roofs or softscaped plaza and podium decks. It is not intended for use in split-slab, podium, or plaza deck design with a hardscaped wear-course like concrete, pavers, asphalt, etc.

This is because there is no inherent capability within RoofJoint to separate topping slab, pavers or other rigid wear course materials from one another at the deck surface to properly accommodate movement in the wear course.

For split-slab, podium and plaza deck design see the FP (For Plaza) series of expansion joints.

If RoofJoint is designed for installation into the structural slab of a hardscaped split-slab or plaza deck design, EMSEAL takes no responsibility for buckling pavers or cracking or binding in topping slabs that will occur as movement from the structural slab is referred through the wear course.

Insulation in the joint opening beneath a roof expansion joint is critical in maintaining energy efficiency in the structure. Insulation under RoofJoint can be achieved in two ways:

Insulation Method 1: Specify and install Horizontal Colorseal beneath RoofJoint.

The advantage of this solution is that in addition to insulating, the Horizontal Colorseal provides an additional watertight barrier beneath RoofJoint that ties into the RoofJoint Wall Closure transition piece and further ensures continuity of seal and insulation with the wall joint. The R-Value of Horizontal Colorseal is 2.15 per inch of depth. Therefore in a 4-inch joint, Horizontal Colorseal has a depth of 4.5 inches and an R-Value of 9.675. To increase the R-Value of any size of Horizontal Colorseal, specify an increased custom depth.

Insulation Method 2: Batt Insulation and Looped Membrane (by Others)

By installing a looped membrane of standard roofing material (by others) to support fiberglass or mineral wool insulation batts before installing EMSEAL’s RoofJoint. While commonly done, this solution provides no continuity of R-value with the wall expansion joint and is subject to insulation value loss through moisture retention due to condensation accumulation in the batt insulation as well as through compression during joint cycling.

  • 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.