Expansion Joints and Pre-Compressed Sealants



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EMSEAL DSM-FP Watertight SplitSlab Expansion Joint for Plaza Decks
The watertight

Watertight & Traffic Durable

Integrates through its side flashing sheets with the deck waterproofing systems of split slab, concourse, and plaza deck design.

• Uniquely suited to joint openings between split-slab and solid slab construction

• Uniquely suited to deck-to-wall and deck-to-column conditions in split-slab construction

Joint Sizes:
Straddles structural joint-gaps 1/2"
(12mm) to 4" (100mm).
Note: Sizes under 1 1/2" (40mm) are manufactured with a single bellows. Larger sizes incorporate multiple bellows

(For larger than 4" (100mm) see SJS-FP)

Movement Capability:
Total 100% movement capability: +50% and -50% of nominal supplied size.

DSM-FP is a trafficable joint system for use in plaza decks and split slabs. It is watertight, and sound-dampened designed for expansion joint gaps measuring 4-inches and less.

The DSM-FP System is designed to provide a watertight, trafficable joint system
in smaller 1/2" (12mm) to 4" (100mm) joint openings, in decks of split-slab
design. DSM-FP expands the use of the DSM SYSTEM to waterproofed split-slab deck designs through the use of side flashing sheets that integrate with the deck waterproofing membrane.

Uses, Applications
• 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 between split-slab and solid slab construction
• Uniquely suited to deck-to-wall and deck-to-column conditions in split-slab construction
• Plaza and podium decks
• Split slab or asphalt-overlay parking decks
• Airport roadways
• Mall bridge connectors
• Stadium concourses, etc.

Product Description
• The system consists of two subassemblies: 1) The structural-slab mounted supporting legs with integral waterproofing side sheets; and 2) the joint sealing silicone-faced foam.

• The mounting leg assembly is delivered with opposing legs factory-set to the nominal joint size. It is installed onto a wet-setting bed of epoxy mortar and bolted to the deck.

• The factory-assembled bellows and foam manufactured at applicable widths and depths are shipped from the factory.

Epoxy gel adhesive is applied to the faces of the previously installed mounting leg assembly.

• The DSM SYSTEM precompressed foam sealant is installed into the joint gap where it self expands into the wet epoxy adhesive.

• Consecutive lengths are joined through the field-application of manufacturer-supplied, low-modulus, high-movement silicone to the intersecting bellows surfaces.

• A field-applied silicone sealant band is injected at the bellows to joint substrate interface to complete the waterproofing.

With the DSM-FP side flashing sheets pulled out of the way, the deck waterproofing membrane is installed on the deck and brought over the top of, and up the DSM-FP mounting leg.

The side flashing sheets are lowered into the liquid membrane (or into the non sag mastic component of a sheet waterproofing system) and sandwiched with another layer of waterproofing.  Drainage board and/or protection board are added in accordance with the designer's preference.

• Concrete, pavers, asphalt, or other topping slab or wearing course material is installed up to the stainless steel retaining caps on the DSM-FP mounting rails with or without a field-applied sealant control joint depending on the wear-course material (consult EMSEAL).

The material that bridges and seals between the DSM-FP mounting rails is EMSEAL's DSM SYSTEM which is comprised of silicone-and-impregnated-foam hybrid components that ensure watertightness, absorb sound, dampen vibration and offer uncomplicated installation. DSM is the latest evolution in the field-proven technology that EMSEAL has used for 30 years of sealing horizontal plane joints with impregnated foam sealants.

Watertight The tensionless silicone bellows are installed essentially flush to the deck surface just below the stainless steel capping strips thereby ensuring watertightness at the wear-course surface. This eliminates the need for secondary moisture barriers and gutter systems.

Continuity of Seal
– All EMSEAL expansion joint systems feature continuity of seal through changes in plane and direction –– an essential performance differentiator. Fabricated transitions from deck to wall, at curbs, sidewalks, parapets, tees, and crosses are available with the DSM-FP.

Split-Slab to Solid-Slab Connections

DSM-FP is an effective watertight expansion joint for bridging split-slab and solid-slab construction. The watertight precompressed DSM foam sealant is held securely in place by utilizing the back-pressure of the expanding foam, epoxy adhesive, and a field-injected silicone sealant band at the substrate interface. The connection to solid-slab construction is made directly to the slab substrate. The split-slab connection is made to the DSM-FP mounting leg. The split-slab connection incorporates an integral waterproofing flashing side flashing sheet embedded between layers of the deck waterproofing membrane on the structural slab and beneath the topping slab.

(L) Solid-Slab to Split-Slab / Deck to Deck                                    (R) Wall/Column to Split-Slab

Sizing Criteria

Joint Sizes: Because DSM-FP installs into its own legs, the legs can straddle mean-temperature, structural slab, joint sizes as small as is determined by the designer to meet deck movement criteria. 

Joints straddled by the DSM-FP system could be as small as 1/2-inch (12mm) and up to 4-inches (100mm). The minimum gap between the DSM-FP legs is 1-inch (25mm).

(For joints larger than 4" (100mm) see SJS-FP)

As seen above, the width between the legs of the DSM-FP installed in the topping slab does not need to necessarily be the same as the joint gap in the lower structural slab. The lower gap should  be no wider than the width of the DSM-FP foam above it, although cantilevered leg options can be configured to suit special conditions--consult EMSEAL.

Performance & Selection

Movement Capability: 100% (+50% and -50%) of nominal material size.

Leg Heights: 3 3/16" inches (80mm) to 12-inches (300mm) 

Note: As joint width increases so does the depth of the DSM precompressed foam--minimum leg heights for wider joints will be determined by the depth of the DSM foam.

Fire Rating
For a similar system with a built-in, up to 2 hour fire rating ask EMSEAL about the EMSHIELD DFR2-FP System.



Model selection is designated by product codes. The code segments relate to the product configuration: For example,

DSMFP-55-400-75 means:

Product Movement JointWidth LegHeight
DSMFP 55 400 75
  (55%) (4" joint) (75mm, 3")

Consult EMSEAL for model number suitable to your specific application.


EMSEAL JOINT SYSTEMS LTD. 25 Bridle Lane, Westborough, MA 01581
EMSEAL LLC. 120 Carrier Drive, Toronto, ON M9W 5R1



1-800-526-8365 -- 508-836-0280 --  techinfo@emseal.com -- Fax: 508-836-0281

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