Successful projects with
expansion joints and joint sealants that don’t leak are characterized by a
commitment by the A/E team, the general contractor, the joint
manufacturer, and the waterproofing sub-contractor to detail,
construct, fabricate, and install three-dimensional solutions.
The general contractor or construction manager plays a critical role in
ensuring watertight expansion joints and joint sealants. As the entity
responsible for the coordination of all trades, the GC is in the position to
set the tone for appreciation of the roles of everyone in ensuring that the
building ultimately doesn't leak. The following suggestions have been
proved to contribute to successful projects:
Expansion Joint Conference
The General Contractor
should call a meeting of all parties involved in the treatment of work at
and around expansion joints. This meeting is to take place prior to any
concrete that will define expansion joints is placed. All superintendents
and forepersons with responsibility for involved in casting activities must
attend this meeting. The meeting will be used to educate all involved
parties as to their responsibilities as outlined in “Expansion Joint
Responsibilities of General Contractor and/or Concrete Sub-Contractor”
addition to the pre-construction expansion joint conference, at all
subsequent progress meetings, expansion joint review, coordination, and
responsibility is required to be an agenda item.
Responsibilities of General Contractor and/or Concrete Sub-Contractor
The General Contractor and/or Concrete Sub-Contractor is responsible to
ensure that concrete, to which expansion joint systems will attach or
otherwise come in contact, is placed so as to facilitate expansion joint
system installation. The General Contractor and/or Concrete Sub-Contractor
is responsible to ensure that the following conditions are met:
decks and floors align, without offsets, with joints in split columns,
walls, curbs, parapets, as well as through crosses, around columns, at
treads and risers, etc.
Structural expansion joints are sized to ensure the accommodation of
expected structural movements. In addition structural expansion joints are
sized to be within the movement capability of the specified joint systems.
Consequently, expansion joint separations are not to be used as a place to
adjust for tolerance build-up from other construction activity. Start all
work from the expansion joints and work outward. If placing precast units,
first fix the units that define the structural expansion joint and work away
from the joints making up tolerances in gaps between the precast units.
are cast at prescribed widths and are a consistent dimension throughout. If
casting at other than specified mean temperature and/or if post-tensioned
slabs are to be cast, General Contractor in agreement with
engineer-of-record is responsible to adjust form widths if necessary to
ensure that resulting joint gaps at mean temperature and/or after
post-tension shortening are at the specified joint width or at a width
within the movement capability of the expansion joint system specified for
solid and solidly fixed to allow concrete next to the forms to be thoroughly
vibrated to ensure proper consolidation and that no voids within or on the
concrete surfaces result.
solid and solidly fixed to prevent them from twisting, bending, tipping or
otherwise becoming dislodged thereby causing irregularities in the joint
joined tightly throughout the length of the joint being cast to prevent
concrete seepage that will result in the need to later remove concrete
blockouts or recesses adjacent to joints in floors, walls, parapets, or
other surfaces are called for, that these blockouts meet prescribed
dimensions and that concrete is vibrated to ensure proper consolidation and
that blockout surfaces are free of spalls, depressions, and other
initial curing of the concrete, forms are to be removed promptly to prevent
them being squeezed or becoming dislodged by joint movement. Forms left in
the joint-gap too long could cause spalling of joint faces which will be
required to be repaired at the General Contractor’s expense using structural
patching materials and techniques.
required to achieve elevations to accommodate expansion joint systems must
be structurally connected to adjacent concrete, properly consolidated and
free of deformities.
formed, expansion joints in decks and floors are protected from damage by
construction traffic. This is to be achieved by barricading the joints to
prevent traffic across joints except at designated crossing points. At
traffic crossing points, joints are to be protected with plates, or ramps.
This traffic management is to be enforced throughout the construction
walls are to be constructed at specified dimension throughout their lengths
as well as through plane and direction changes.
Regardless of substrate material, joints in walls must have sufficient depth
to support the full depth of the expansion joint system to be installed plus
½” (12mm). As necessary coordinate with the responsible trades the addition
of angles, returns, solid masonry units, mullion caps, and other such
additions to metal-panels, brick, stone, CMU, window systems etc., to ensure
the presence of fully supported and watertight substrates.
walls are to be free of mortar protrusions, masonry ties, protruding shelf
angles, and other obstructions that might hinder movement at the joint or
obstruct installation of the expansion joint system.
time of installation of expansion joint systems any deviations from the
above requirements will be rectified by and at the expense of the General
Contractor and/or Concrete Sub-Contractor. All remediation work shall be
carried out using materials and methods of structural concrete repair to
ensure that originally intended conditions are achieved.
Responsibilities in Coordinating Subcontractors in Relation to Expansion
The General Contractor is responsible to coordinate and schedule all
subcontractors including, but not limited to, concrete, mechanical,
electrical, HVAC, landscaping, masonry, curtain wall, façade-panel,
waterproofing, caulking, flooring and other finish trades, in a manner that
ensures that expansion joint installation can progress unimpeded.
All subcontractors are to understand their responsibilities in relation to
expansion joints and that their work cannot impede structural movement that
will occur at expansion joints or compromise the achievement of
watertightness at expansion joints in any way.
All subcontractors are to ensure that their work in relation to expansion
joints is properly executed and that accommodation for appropriate movement
in their materials is made. Installation of any materials at, around, or
through expansion joints that impedes movement at the expansion joint or
impedes installation of expansion joint systems will be required to be
removed and reworked.
If a 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 headaches.
We invite you to make EMSEAL your partner
in success on your expansion joint project.
General Contractor Expansion Joint Responsibilities
Division 3 Addendum (.doc)