Expansion Joints and Pre-Compressed Sealants
The EMSEAL Approach to Successful
Expansion Joint Treatment--Collaborative, 3-D Design, Detailing,
Construction, Fabrication, Installation
(click images to enlarge)
blueprint was taken from an actual set of design documents produced by a firm
tired of the endless stream of RFI's and change orders that resulted from
ignoring or delaying the consideration of expansion joints until during
construction. Beyond the delays and cost overruns, their projects
additionally typically had a legacy of leaks. Having adopted the
EMSEAL approach to expansion joint design, their projects are instead now
distinguished by trouble-free expansion joints.
It’s not just about products.
While EMSEAL prides
itself on having high-quality, innovative and durable materials for use in
sealing and bridging small and large, building component and structural
joints in foundations, decks, walls, and floors, the company’s
record of successfully completed projects is equally attributable to
the designers, general contractors, and installers engaged in a
collaborative approach to expansion joint treatment:
Anybody can make an
expansion joint appear watertight in cross-section. However,
joints leak at changes in plane, direction and where dissimilar joint
Successful projects with
expansion joints that don’t leak are characterized by a collaborative
commitment by the A/E team, the general contractor, the joint
manufacturer, and the waterproofing sub-contractor to think, design, detail,
construct, fabricate, and install three-dimensional solutions.
The process begins at
design with the visualization by the A/E team and the joint manufacturer
of expansion joint locations, layout and impact on all other adjacent
materials and spaces.
This visualization is
aided by the use of simple isometric line sketches of joint layouts
which reveal conditions that could be designed-out, simplified, or for
which details must be developed. The A/E then supplements the
usual cross-sections with axonometric details of conditions involving
changes in plane, direction and between dissimilar materials.
To these conditions, the
expansion joint manufacturer must furnish
CAD details showing their materials adaptation to these
conditions. The manufacturer’s application of their material
to the designed conditions should be warrantable as watertight at all
agreed upon changes in plane, direction, and intersection between various
joint materials. Additionally, the manufacturer can be vetted at
design stage for their ability to factory-fabricate, reinforce, and
warrant their materials through multi-directioal movements including
shear. The final isometric layout(s) and all
cross-section and isometric details then become part of the bid
documents and working drawings.
Before and during
construction the general
contractors' role is to elevate the place that expansion joints
typically occupy in the sequencing path. ALL trades must be held accountable for their work in relation to
expansion joints. The joints, for example, must be protected from
construction traffic damage and cannot become a place to accumulate
The expansion joint
subcontractor must commit to taking field measurements from which the
manufacturer can fabricate and furnish factory-welded, warranted
assemblies to install into the relevant joint locations.
approach is not just theory. It is a practice that has
resulted in the successful execution of watertight expansion joints on new
and retrofit projects on structures of every type.
If this collaborative and
disciplined approach is not adopted as the basic philosophy on any project
of any scope, whether a stadium, hospital, school, government building or
airport, it can be expected that leaks at expansion joints will constitute
a high percentage of post tenancy costs and headaches.
Think, Design, Detail, Specify, Construct,
Fabricate and Install in 3D.
simple guideline for successful expansion joint treatment starts with the
designer and is picked up by the GC, subs and manufacturer.
The following images are taken from the
plans of one of the many A/E firms who have discovered that the adoption of
this approach can profoundly affect the delivery of a watertight,
hassle-reduced project to their clients
Left: A simple isometric of structural expansion
joints on a project can reveal the EJ's impact on every aspect of the
building. This affords the design team the opportunity to simplify the
project or relocate the joints or impacted elements.
Left: References on the isometric to cross-section
and isometric details on a details page show the designers' intent for changes in
plane and direction and treatment of materials at transitions between
systems. This allows the sub to include for these transitions in his
estimate and reduces time-consuming RFI's and the costs of change-orders.
For PDF's of the above drawings, click