Expansion Joints and Pre-Compressed Sealants
• Dual-faced, silicone coated, primary seal
• Easy installation, non-invasive anchoring
• Below grade negative-side installation
• Below grade walls
• Slab on grade / foundation floors
• Tunnel walls, ceilings and floors
• Planter walls to seal inside planter and outer wall
• Wastewater digester
lids to seal out weather and contain methane for harvesting
• As containment for injected polyurethane grouts
*for floor joints larger than 4" (100mm) and larger, where an integral coverplate is desired, consider SJS System
up to 100% Total (+50% and -50% of nominal supplied size.)
DSM-DS is a unique, highly resilient, double silicone faced
precompressed sealant that has proved over the years to be able to solve
difficult joint sealing problems where other systems have failed or are not
suitable. As such, it is ideal for new installations as well as expansion
joint repair or retrofit jobs. Some examples of DSM-DS applications include:
Digester Lids to Facilitate Methane Harvesting: DSM-DS has been
used as a digester-lid perimeter joint sealant at wastewater treatment
plants that harvest methane. Installed between the tank wall and the
digester lid, DSM-DS keeps the weather out while keeping the methane and
other gases in. The products ability to resist gas pressure depends on
the joint size and the expected pressure--consult EMSEAL.
See Jamaica WWTP Project Summary.
Walls and Ceilings To Redirect Positive-Side Water Flow from the Negative
Side: Existing Tunnel Structures often leak at expansion joints due to
water draining through the surrounding ground and accumulating on the tunnel
lining. Few options exist for addressing structural expansion joints in this
situation. DSM-DS installed from inside the tunnel (the negative
side) has proved its ability to redirect the positive side water around the
tunnel lining where it can be manage to drains to filtered away in the
surrounding drainage-coarse gravel. The ability of the DSM-DS to effectively perform
this role depends on there being active shedding of the water to prevent the
accumulation of a head pressure--consult EMSEAL.
See Wheeling Tunnel Project Summary.
Walls: Planters that are bisected by structural expansion joints
present a unique sealing challenge. The joint in the inside of the
planter must be sealed to prevent irrigation water from leaking out of the
planter into the structures below or adjacent. The outside of the
joint in the planter walls must be sealed to fill the joint aesthetically
and to keep the weather out. DSM-DS, because it can be customized in
depth to suit the thickness of the planter wall, and because the outer
silicone bellows can be supplied in any of 26 colors, can be made to
coordinate aesthetically with the finish of the outer face of the planter
walls. This means both the inside and outside of the planter can be
sealed in a single installation step.
Floors and Walls from the Negative Side: It is not uncommon for
existing foundations to leak at structural expansion joints. The
surest way to remediate this type of leakage is to excavate to expose the
foundation to address the waterproofing from the positive side. As
this is seldom practical, a solution from the negative side is often sought.
This conditions is very difficult to address especially where any sort of
head pressure is likely to build up.
DSM-DS alone has been
successfully used in many cases to stem the flow of water into foundations
where a perimeter drainage system on the outer side of the foundation wall
and floor is functioning. The perimeter drainage or some other active
drainage system (ex. pumps) is necessary to keep the blocked water from
building a head pressure against the back side of the DSM-DS.
for Injected Polyurethane Grout: In some more difficult cases
where head pressure is likely to build and where active drainage is not
present, DSM-DS has been installed to seal off the joint gap and to act as
containment for polyurethane grout injected through the wall behind the
DSM-DS. The grout when subjected to water pressure is held in place by
the resilience of the DSM-DS.
Click here to see
who else is using DSM and DSM_DS?
DSM-DS is a watertight,
precompressed primary seal with dual factory-applied
opposing-face silicone bellows. It is constructed from acrylic-impregnated
hydrophobic foam containing
no waxes or
Water Management: DSM-DS in the Wheeling (WV) Tunnel
Harvesting Containment: DSM-DS in the Jamaica (NY) Waste
Water Treatment Facility
• Non-Invasive Anchoring—there are no hard
metal-to-concrete connections in the system. This includes
embedded pins, anchors, screws, bolts or tracks, trays or
rails. The system is locked to the joint faces by means of the
1) backpressure of the foam; 2) the epoxy adhesive, and 3)
from injected silicone sealant bands at
the joint face to foam and silicone bellows interface.
• Continuity of Seal—as in all EMSEAL expansion joint
systems, continuity of seal through changes in plane and
direction is an essential performance differentiator. Details
for watertight, field-fabricated transitions from walls,
floors, tees (etc.) are
available with the DSM-DS SYSTEM.
• Movement Capability
+50% and -50% (Total 100%) of nominal material size (see
• Aesthetics & Versatility—Standard color is gray (other
colors available), uniform bellows appearance, double sealing,
and an enhanced ability to handle variations in joint size are
among other system features.
• Capable of movements of +50%, -50% (100%
total) of nominal material size. *for floor joints larger than 4" (100mm) and larger, where an integral coverplate is desired, consider SJS System.
• Substrates must be
parallel, plumb and capable of resisting approx. 2.5 psi
backpressure from the foam.
• Standard sizes from 1/2" (12mm) to 6" (150mm).
• DSM-DS is produced by coating an impregnated cellular
foam with silicone on opposing outside faces.
• The expanding foam is cellular polyurethane foam impregnated
with a water-based acrylic containing a high performance
• The silicone external facing is factory applied to the foam
at a width greater than maximum joint extension and is cured
before final compression.
• Silicone application and curing takes place in a
factory-controlled environment. In contrast to field applied
liquid sealant and backer rod installations, no movement takes
place during curing that can cause deformation or stresses in
• When compressed, a bellows is created in the coating. As
joint movement occurs the bellows simply folds and unfolds
free of tension on the bond line, and virtually free of tensile
stresses in the silicone material.
• The foam provides a resilient backing to the silicone
coating, making the system capable of withstanding external
• DSM-DS is supplied in 6.56 LF (2m) shrink-wrapped lengths
(sticks). It is precompressed to less than the joint size for
easy insertion. After removal from the shrink-wrap and hard
board restraining packaging, it expands gradually.