Expansion Joints and Pre-Compressed Sealants

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BLOG: Expansion Joint News, Information, Observations


Got it Rough? You Need SEISMIC COLORSEAL for Rough-Faced Expansion Joint Substrates

We got a ping through online chat last week about rough limestone and its suitability as a substrate for an expansion joint.

it's a great question because so many of the old technologies -- compression seal, strip seal, closed-cell foam -- would have left this building leaking.

SEISMIC COLORSEAL on the other hand is ideally suited to sealing rough substrates. Why?

First of all, it is always in compression. We make SEISMIC COLORSEAL from more foam than the size of the opening. In fact we use more foam than even the widest expected opening of the joint due to movement.

Next, the impregnated foam backing is pliant. Under the backpressure of compression it conforms to the irregularities of the rough substrate.

And, the contractor shoots a corner bead of silicone between the substrate and the outermost precured silicone bellows on the face of the SEISMIC COLORSEAL. This locks the system to substrates and seals off even any pin holes not filled by the foam.  [keep reading]

Published April 14, 2015  Lester Hensley

Sealant Waterproofing Restoration Institute Spends 5-Minutes
with Lester Hensley

Applicator: What do you most enjoy about your work at EMSEAL?

LH: At EMSEAL, we believe in a more durable, reliable, energy efficient and safe, built environment. We contribute to the realization of this goal by offering innovative expansion joint and sealant products that work. We believe that far too much is wasted throwing good money at bad design and the installation of products that are not thoroughly conceived, detailed, and communicated. We believe that in partnership with like- minded architects, engineers, general contractors, and waterproofing and restoration contractors, it is possible to deliver watertight, lowest-total-cost- of-ownership structures to property owners. The most satisfying part of my work is when this is realized. With thorough collaboration, we can deliver a project that makes the owner happy, minimizes conflict, and allows all parties to make a profit that is not eroded by callbacks, failures, or complaints. <continue reading>


Published April 1, 2015  Lester Hensley

Bridge Expansion Joint System, BEJS, selected for 2014 AASHTO Innovation Initiative

The AASHTO Innovation Initiative advances innovation from the grassroots up: by agencies, for agencies, peer-to-peer. The program actively seeks out proven advancements in transportation technology, investing time and money to accelerate their adoption by agencies nationwide. Each year, the program selects highly valuable technologies, processes, software, or other innovations that have been adopted by at least one agency, are proven in use, and will be of significant benefit to other agencies.


Additionally Selected Technologies (ASTs)

The AII cannot always fund all of the nominated technologies that are ready for implementation and stand out above the rest. Because of this the AII has created this new designation to promote these technologies.  BEJS is the only technology chosen in 2014 for three categories out of four: Construction, Maintenance, and Design.


Published September 12, 2014 -- Dan O'Hayer  

Three New Patents in 2014, Three in 2013, Prove EMSEAL's Ongoing Commitment to Innovation

With two new patents issued in August and another in June this year, EMSEAL continues to demonstrate its commitment to investment in R&D and innovation in the field of expansion joint sealing and fire-proofing. The EMSHIELD line of all-in-one expansion joint systems provides designers with a new freedom from cumbersome and less-effective underslab and multi-product solutions for floor and wall fire-proofing, sealing, insulating and sound blocking.

With these recent awards EMSEAL adds to its considerable list of active patents, and has many more pending, in its field. The company’s body of patents now in the public domain is nearly as long and further demonstrates its decades-long commitment to raising the bar on effectiveness and simplicity-of-installation of these building components so critical to life-safety as well as to the high performance expectations of the modern built environment.

“We have never been content just to copy what’s already out there,” comments Dan O’Hayer, EMSEAL’s President. “Innovate, Don’t Imitate” has long been our R&D mantra.”

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Published September 3, 2014 -- Dan O'Hayer


"Shear" Genius--Shear Pocket Innovation Enhances Movement of Deck and Roof Expansion Joints

Developed by EMSEAL over 20 years ago, shear pockets are a loop of Santoprene thermoplastic rubber welded to replace the center member or cells of an expansion joint extrusion.

Shear pockets enhance the ability of extruded expansion joints to handle extraordinary shear movements where joints change direction and plane.

Shear pockets are an option available from EMSEAL in the extruded, thermoplastic rubber, Santoprene seals of our THERMAFLEX TM and TCR, MIGUTAN, and RoofJoint expansion joint systems.

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Published July 24th, 2014 -- Dan O'Hayer

"Expansion Joints Are Ugly"

We occasionally hear this objection from architects. 

Notwithstanding that eye-of-the-beholder thing, it may be true--if you actually see the joints.

Most people don't ever notice expansion joints. They're certainly not the visual focal point of architecture.

As expansion joint material manufacturers, in order to inform designers about our products and how they work, we need to show close ups.  However, it's more likely that they'll never be seen.

We continue to innovate to provide aesthetic improvements in our product offerings, however, decisions made early in the design process can be as big a driver in making joints unnoticeable. 

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Updated May 28th, 2014 -- Lester Hensley

Superbowl Joint System from EMSEAL Ready for Showdown

EAST RUTHERFORD, NJ--As the Meadowlands prepares itself for its biggest day in football--Superbowl XLVIII--one thing is for sure--the stadium expansion joints are ready.

In the same way that the Meadowlands ushered in the era of billion dollar stadiums, it also marked a watershed in the structural expansion joint industry. With seismic stadium expansion joints 10-inches (250mm) wide, and a design requirement that they be watertight at the deck surface, through all direction and plane changes, between different deck and wall technologies, and capable of handling rolling point loads in concourses and split-slab conditions on the upper decks, the scope of performance expectations was extraordinary.

With design by 360 Architecture, architectural detailing by Ewing Cole,  and structural engineering by Thornton Tomasetti, all working under a design-build arrangement with SKANSKA USA, bridging and sealing these large (10-inch nominal) seismic expansion joints fell to EMSEAL and installer Schnell Contracting Services 

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Posted January 31, 2014 -- Lester Hensley

UK Car Parks Benefit from EMSEAL Watertight Expansion Joints

The Meadowhall Centre in Sheffield, South Yorkshire, is a truly massive retail attraction offering 280 stores providing 1.5 million square feet of retail space. The popularity of the centre has seen it increase its parking provision over the years, including the building of new parking decks. It now provides 12,000 free parking spaces, as well as access via rail and Sheffield’s Supertram system. The Meadowhall Centre has won many awards for its retail offers and its engineering. But the centre also had a problem. Over a decade of traffic had exposed the reality that the complex’s parking structure was leaking. The cause was something quite simple – the failure of rubber used to seal the car park’s expansion joints (also known as movement joints).


Posted November 26, 2013

Expansion Joint Training Dates Set Through 2014

EMSEAL's highly praised, SWRI-Validated Expansion Joint Training program has been a draw this year for more than 150 architects, engineers, consultants, contractors, distributors and reps from around the world.

The 8-CEU, AIA-registered program combines practical hands-on installation training with history, design, technology failure analysis, safety, and quality assurance training.

The program dates are on the training page. Sign up!  Come and see what all the fuss and fun is about...


Posted October 24, 2013 -- Lester Hensley

Lowest Total Cost of Ownership Building Expansion Joints

After 10 years of watertight operation, the building expansion joints at 100 Cambridge Street, Boston are trouble-free. 

This means the owners aren't spending money on maintenance. It also means they have no leaks into tenantable space.

The complex that includes the Saltonstall government office building, luxury condos, and retail has benefited as a result, from a cornerstone of EMSEAL's expansion joint philosophy--do the work up front and provide the best quality to ensure the lowest total cost of ownership expansion joints possible.

The technologies employed are COLORSEAL in the walls and EMSEAL's FP-series in the plaza deck.  


Posted August 2, 2013 -- Lester Hensley

(click to enlarge)

Seismic Joint System (SJS) for Interior Floor Joints--Watertight, Fire-Rated

Our SJS SYSTEM has an unrivaled track record in sealing stadiums around the world. It has a similar track record in addressing parking deck expansion joints.

Now SJS and it's UL2079 certified fire-rated version, SJS-FR, are increasingly being used in interiors. 

The El Dorado International Airport in Bogota Columbia recently chose SJS-FR for its ease of installation, ease of work phasing and for the built-in fire rating.  Installation from the floor surface eliminates the need to access the underside of the slabs while non-invasive anchoring simplifies installation and reduces installation time.


Posted August 1, 2013 -- Lester Hensley

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"Like Drinking from a Fire Hose"--Now That's an Expansion Joint Water Test

When it came down to water testing the central parking garage expansion joints at Will Rogers World Airport, these guys didn't mess around.

DSM SYSTEM was chosen for the retrofit of the top deck parking structure expansion joints at Will Rogers International Airport in Oklahoma City.

A rigorous water test proved the system and all joins between lengths and at dozens of crosses, watertight.


Posted July 26, 2013 -- Lester Hensley

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Laminations as a Build Choice -- The Anatomy of Quality in Pre-Compressed Foam Sealants

EMSEAL would like to extend our thanks to the architects, engineers, consultants and contractors who, for more than 30 years have entrusted the waterproofing of their expansion joints to EMSEAL.

Together we have built an unrivaled track record of success. 

For decades EMSEAL has chosen to build our foam sections, in sizes where it makes sense, from vertically-aligned, self-adhering, compression-bonded laminations. 

You don’t know this because it is irrelevant to you. 

What is relevant is that the products work in the applications, and at the movement extremes for which we offer them.  And they do.


Posted July 26, 2013 -- Lester Hensley

EMSEAL DSM fully uncompressed showing the uniformly-impregnated foam laminations chosen for purposes of maintaining quality and consistency.

What's the Best Roof Expansion Joint Design?

What is preferred:  all pre-compressed foam joints for roof and walls or RoofJoint with foam for verticals? What are the criteria for specifying one over the other?”

The answer to the first question is, “both”.

The best roof design--where the desire in today’s world of advancing building science is for a totally sealed, best insulated building envelope--is to install the RoofJoint over HORIZONTAL COLORSEAL in the roof and SEISMIC COLORSEAL in the walls and connect the walls to the RoofJoint with the SEISMIC COLORSEAL RoofJoint Closures.

For both cavity wall and solid wall construction, the best roof expansion joint designs look like this:


Posted July 26, 2013 -- Lester Hensley

(click to enlarge)

Gutters Hide Expansion Joint Leaks

These photos received by our Tech Team inspired a re-post from our FAQ:

Why does EMSEAL discourage the use of gutters?

The photo illustrates vividly why expansion joints should be watertight at their top surface.  And why gutters can lead to the need for seriously costly repairs.

They underscore how gutters conceal leaks, resulting in structural damage that is dangerous and far more costly than the price of an expansion joint that works.


Posted January 11, 2013 -- Lester Hensley

Expansion joint gutters conceal leaks, lead to costly and dangerous concrete deteroriation
(click to enlarge)

EMSEAL Embraces, Enables Sustainability

From EMSEAL, the Westborough, MA based company that sealed all 6,514 windows on the Empire State Building LEED Gold retrofit, comes news of their own more local sustainability efforts. Like this massive project, which resulted in a 38% energy savings for the 102-floor, 2,900,000 square foot, New York skyscraper, EMSEAL has similarly achieved a substantial reduction in energy usage due to its recent efforts facilitated by the Sustainable Business Leader Program (SBLP).

EMSEAL is recognized by SBLP as a leader in sustainable business and partner in debunking the myth that companies must choose between profitability and sustainability.

Says EMSEAL CEO Lester Hensley, “Because of our financial and cultural success with this program, I would encourage any and all local businesses to explore SBLP certification, or to pursue similar local and national sustainable business initiatives.”
Posted June 29, 2012--Jordan Hensley

Rethinking Expansion Joints in the Face of Quakes and Hurricanes

Expansion joints can be said to be among the most critical aspects of design in relation to building performance under geological and weather extremes.  


In the wake of the recent earthquake, hurricane Irene, and tropical storm Lee, those of us on the East Coast are being given repeated reminders of a universal truth--storms and shakes need to the baseline for our structural design.  

new line of breakthrough expansion joint products means you can get extreme protection built into a single product installation with solutions for walls, floors, solid and split slabs.
Now is a logical time to reflect on design practice as it relates to expansion joint sizing and product selection in relation to earthquakes and storm-force-wind driven rain.

Posted September 6, 2011--Lester Hensley

Do Expansion Joint Leaks Plague your Projects?

"We have come to realize that our projects show more problems with expansion joints than all other product categories combined.  Yet, expansion joints are a miniscule part of projects in terms of construction costs.  How can we work together to produce trouble-free joint seals?"   

Received in a letter to our firm in 1990, this quote has been the basis of EMSEAL's mission for 20+ years. Less than 1/2 of one percent of the budget of a structure is typically spent on expansion joints.  In fact less than one percent is usually spent on all waterproofing. Yet, waterproofing related issues constitute a lions share of post-tenancy complaints and revenue disruption and are involved in an estimated 90% of construction-related lawsuits.  

We can "work together" to produce trouble-free joint seals. It involves a collaborative process, begun early in design stage and includes the incorporation of a couple of simple sheets to your bid documents. Architects, engineers, and general and sub contractors everywhere are adopting our 
"Think, Design, Detail, Erect, Manufacture and Install
3-Dimensional Expansion Joint Solutions"
approach to joint sealing.  To find out how, 
schedule an EMSEAL lunch seminar now or read more about it at emseal.com.


Posted March 11, 2011--Lester Hensley

Could You Pass UL 2079?
SJS-FR2 -- 2-hour Fire Rating Built-In to SEISMIC JOINT SYSTEM from EMSEAL

Try this:  from a deep, knees-bent squat, stand up to your full height and squat back down again, slowly, taking 6 seconds to complete the cycle.  Do that 400 times.

Now squat down and stand up 100 more times every 2 seconds.

Take a day to recover, and then (don't try this) lie on your back over an 1850°F (1010°C) fire for two hours. 

If your belly-button doesn't reach more than 356°F (180°C) AND your head, toes and belly-button averaged together don't exceed 248°F (120°C) then you've passed.  Oh, and you can't crumble and fall completely into the fire either.


SJS-FR2 is the latest expansion joint from EMSEAL to pass the rigorous UL 2079 standard.

Posted September 22, 2010--Lester Hensley

20+-year Run at the Guggenheim--EMSEAL's COLORSEAL a Permanent Exhibit at Historic Landmark Museum


We are often asked how long our products will last.  The answer often is "we have installations in place over 25 years old."

But one is never really sure, until you go and take a look.

Seeing the Guggenheim museum has been on my bucket list for a long time. I can't believe it took so long for me to get there.  All of the anticipation did not, as it often can, result in disappointment.  I was duly impressed by the genius of Frank Lloyd Wright's accomplishment--and enjoyed the art exhibit too. 

The icing on the cake came from the opportunity to inspect the going on twenty-year-old installation of COLORSEAL between the neighbors and the 1992, 9-story, limestone-clad administration tower seen to the left of the original museum in the photo above.


(Image ©Hackman www.depositphotos.com)

Posted August 12, 2010--Lester Hensley

Another Fire-Rating First--Seismic Traffic Joint is UL 2079 Fire Rated up to 2-hours--EMSHIELD SJS FR

One Install Does it All--Fire Rating, Watertight, Traffic Durable, 100% movement.  No anchors, no fire-blankets, no gutters.  

In another industry first, EMSEAL has built the fire-rating into the joint--this time for floor and deck joints subject to cars, pedestrians, material handling equipment and other loads.

 Installed entirely from the deck or floor above, no utility lifts or holding labor are required. And, installation and continuity of the fire barrier is not compromised by under-slab obstructions from HVAC, electrical, plumbing or mechanical equipment.

SJS-FR is UL and ULC certified for joints from 4-10 inches with up to 100% of joint size movement and meets the requirements of ASTM E1966, ASTM E119 and ASTM E1399.

Click here for more on SJS FR and the EMSHIELD product line.

Posted July 30th, 2010 Lester Hensley

Waterproofing Plaza Deck Expansion Joints With Buried Sheet Goods--Penny-Wise, Pound-Foolish 

We received an emailed photograph from one of our sales reps today.  Here it is:
It shows pavers on a split-slab plaza deck--buckled up, cracked, dislodged and missing.  The cause?  Movement from the structural expansion joint in the structural expansion joint below.  So why the mess?  The owner of this plaza was the unfortunate beneficiary of an attempt to save a few bucks by using a "buried band-aid" expansion joint waterproofing solution. 

This means that rather than using a purpose-designed, watertight, plaza deck expansion joint, a single-ply sheet of rubber was laid over the joint and tied into the deck waterproofing system.


Buckled pavers on a plaza deck caused by movement at the structural expansoin joint.

Posted July 23rd, 2010 Lester Hensley

Sealing Joints In Swimming Pools--Submerseal Handles the Pressure

Swimming pools, fountains, water parks and water features pose a real challenge in joint sealing.  Durability in chlorinated or salinated water, combined with hydrostatic head pressure make these applications particularly troublesome.

Over the past year, EMSEAL has been simulating continuous head pressure immersion with various pre-compressed sealant configurations and sealant chemistries. 

The result of this research is Submerseal.  The unique crowned bellows configuration combines with and epoxy adhesive and field-injected silicone sealant bands and corner beads to produce a sealant system that resists both hydrostatic head pressure as well as chemical attack from chlorine concentrations typical of swimming pools.

For submerged applications Submerseal has been tested in a hydrostatic-head pressure simulator to continuously resist water pressure at various levels without leaking. Reference the depth table at the Submerseal product page for joint-width and corresponding allowable depths and/or consult EMSEAL for application specific conditions.

Submerseal swimming pool joint sealant by EMSEAL in 12-foot hydrostatic head condition.
Installation of Submerseal in a 12-foot deep swimming pool at a waterpark.

(Click image to enlarge)

Posted June 21st, 2010 Lester Hensley

Why QuietJoint?  New EMSEAL Product Fills Gaps and Market Need

Over the years, we have been repeatedly asked for a cost-effective way to mate mullion to window or wall at partitions. 

Partition closures seal the gaps created by semi-permanent, reconfigurable and even permanent partition walls.  Acoustical privacy, it seems, is the biggest problem created when demising walls are added after the shell of the building is already in place. Not far behind the blocking of sound is the control of HVAC balance--keeping separately zoned spaces from influencing one another is an endless tenancy contention. 

As we have learned from independent-laboratory-conducted sound attenuation studies, EMSEAL products are remarkably adept at blocking sound.

From similar studies on the thermal insulating properties of our products, we have proved some very good R-Values as well.  We pioneered QuietJoint for a project in California where office partitions abut an exterior curtainwall system.  The horizontal mullions (just as in the photo above) created a gap that was allowing sound to pass between rooms.  QuietJoint quickly, and aesthetically filled the gap and stopped the noise.

Posted June 16th, 2010 Lester Hensley

Even a Small Stadium Can Cause Big Expansion Joint Headaches--Not the case for Notre Dame's Melissa Cook Softball Park Though.

A delightful little ballpark, Mellissa Cook Stadium proudly serves Notre Dame's Fighting Irish softball team.  It also proudly serves the University's engineering department as a facility that was waterproof and did not leak since the day it was built. 

This is in large part due to the selection of EMSEAL's DSM SYSTEM for the expansion joints.  DSM is one of EMSEAL's line of precompressed, preformed joint sealants that offers a durable alternative to backer rod and wet sealants.  In joints as small as 1/2" and up to 1 3/4" sometimes varying across that entire range in a single run, the DSM SYSTEM was sized to suit the changing joint widths. 


Posted April 26, 2010 Lester Hensley

Airport Floor Expansion Joints and the Common Law of Business Balance...in other words, "you get what you pay for".

Floor expansion joints for Richmond Aiports new floors Airport expansion joints suffer point loads from all manner of rolling traffic. Airport floor expansion joints, MIGUTRANS, from EMSEAL
(click images to enlarge)

When Richmond International Airport undertook a major upgrade and expansion in 2008, it joined a growing list of airports that have, or are over time, upgrading their interior floor expansion joints to EMSEAL MIGUTRANS.  Why?  The run-of-the-mill floor expansion joints available from a dozen manufacturers are victims of a race to the bottom of quality.  Driven by price, aluminum grade, extrusion thickness, and anchoring methods have been slowly downgraded.  The result are joints that cannot handle the point-loads of modern building floors. 

As nineteenth century observer of society and the construction arts, John Ruskin commented:

“It is unwise to pay too much, but it’s worse to pay too little.  When you pay too much you lose a little money—that is all.  When you pay too little you sometimes lose everything, because the thing you bought was incapable of doing the things it was bought to do.  The common law of business balance prohibits paying a little and getting a lot.  It can’t be done.  If you deal with the lowest bidder, it is well to add something for the risk you run, and if you do that you will have enough to pay for something better.”

Airports especially see traffic that induces repeated rolling point loads that reek havoc on lightweight expansion joints.  MIGUTRANS from EMSEAL's comprehensive selection of durable floor joints, is a heavy-duty, interior floor expansion joint system that provides a smooth rolling and traffic surface, handles heavy loads, and integrates aesthetically into floor finishes.

Posted February 26, 2010 Lester Hensley

A Waterproof Solution for the Plaza Deck at New York's Famous Lincoln Center

EMSEAl MIGUTAN Lincoln Center Plaza Around Column Watertight Expansion Joint EMSEAl MIGUTAN Lincoln Center Plaza Metropolitan Operahouse Watertight Expansion Joint

The very public plaza at North America’s premier music venue, Lincoln Center in New York City, had a continuing problem with leaking plaza expansion joints. Almost since its initial construction in 1959, it had been leaking water from the grand plaza to the underground parking levels below. Two subsequent retrofits of new expansion joint systems still failed to remedy the leaks. The fourth attempt at a fix was planned to be an expensive custom solution designed exclusively for Lincoln Center involving years of engineering and a significant manufacturing and installation cost to the developers. And even then it would be an untested solution hoping to alleviate the problem.

In 2008 EMSEAL entered the discussion, introduced after recent successes at other high-profile New York City installations including Yankee Stadium. After reviewing EMSEAL waterproofing projects in New York and Washington, DC, the decision was made to install EMSEAL’s MIGUTAN system. With a 30-year track record and tens of thousands of feet installed and functioning, the MIGUTAN expansion joint system has proven to be well suited for applications, particularly over occupied space, where the totally watertight integration of expansion joint and deck membrane are a fundamental requirement of the split-slab construction as found on this plaza deck. Its unique design incorporates side membranes which integrate with the deck waterproofing system to form a continuous, completely watertight system. After installation the final view for pedestrians is that of a
simple pair of closely aligned steel capping strips straddling a thermosplastic rubber gland.

Technical personnel at EMSEAL created CAD details and manufacturing plans to adequately address the hundreds of feet of plaza expansion joint to be installed in this retrofit application. They paid particular attention to maintaining continuity of seal through the transitions at direction changes around columns as well as at terminations.

The result today is a watertight solution at Lincoln Center’s famed plaza. Exposed to severe water, snow and the temperature ranges found in the northeast United States, as well as hundreds of thousands of visitors and accompanying foot traffic each year, EMSEAL’s MIGUTAN system is keeping water from leaking through the deck. Avery Hall, the Metropolitan Opera House, the NY State Theater and the Julliard School of Music finally have a watertight public plaza deck worthy of the Lincoln Center’s great fame

Posted February 2, 2010

Curved Expansion Joints?  EMSEAL Bends Over Backwards, Longways, and Sideways for You...

 Curved expansoin joint in skylights handled by precompressed sealant--SEISMIC COLORSEAL by EMSEAL Curved expansion joint along curb at JFK JetBlue arrivals roadway--MIGUTAN by EMSEAL Curved expansion joints custom made for elliptical columns at Nationals Ballpark--MIGUTAN by EMSEAL.
Whether in curved skylights at St. Louis Lambert Field, roadways at JetBlue, or around elliptical columns at the Nationals Ball Park, curved expansion joints more common than you'd think.  Regardless of the radius and the material best suited the application, EMSEAL has the expertise to not only follow the curve but make the joints watertight while handling the structural movements you're designing for.  Our precompressed foam sealants-SEISMIC COLORSEAL (above left), MIGUTAN split-slab system (above middle and right); and our THERMAFLEX winged seals can all be fabricated to follow your curves.  For more on this subject read the article in our Knowledge Base or contact us.

Posted January 20th, 2010 Lester Hensley

Expansion Joints have evolved.  Find out how with a visit to or from EMSEAL

We all came from somewhere. 

Before concrete there was stone.  Before microsphere-modified acrylic polymers, there was tar. 

EMSEAL is proud to have evolved with changes in material and building science.  We would love to share with you, in person, the latest in expansion joint sealing—from our breakthrough SEISMIC JOINT SYSTEM, to our revolutionary fire-rated, watertight, sound-blocking, hurricane-resistant EMSHIELD product line for floors, walls and decks.  As proud as we are of the product line, our approach to expansion joint treatment is as developed.  Continuity of seal, non-invasive anchoring, 3-D joint design, and checklist-based quality assurance are all hallmarks of an evolution in expansion joint treatment.

Contact us to find out where we'll be in your area, to set up a visit to your office, or to join us at our SWRI-Validated training seminars at our HQ. 

Cartoon courtesy of Julia Hensley--artist and teacher who's series dubbed "The EM-SIDE (with appropriate what have yous to Gary Larson)" will occasionally be featured here in the future.

Posted January 20th, 2010 Lester Hensley

Expansion joints have evolved with material and building science. Find out how from EMSEAL.

(click to enlarge)

Tired of Noisy Plates and Leaking Expansion Joints, Prudential Center Boston Switches to Seismic Joint System

Joining a growing list of owners and managers that are tired of noisy, leaky expansion joints, Boston Properties is upgrading many of its joints to EMSEAL.  At this location at and entrance to it's vast underground parking deck the parking deck joint selection was SJS SYSTEM

Unlike noisy self-centering-bar and coverplate joints, SJS has absolutely no metal anchors into the concrete.  The foam-flanked centering spline holds the plate which rides on the concrete or on EMSEAL's sound and impact-absorbing nosing material.

Since its installation, the SJS SYSTEMS has been maintenance free.  Featuring aluminum coverplates (stainless steel also available), and an ADA compliant coefficient of friction, the SJS SYSTEM is watertight, quiet, traffic durable, non-invasively anchored and aesthetically coordinated.

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Posted January 19th, 2010 Lester Hensley

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"Tomato, tomahto "--Carpark, Parkade, Parking Deck, Parking Garage--No Matter What you call them, the expansion joints shouldn't leak...

Expansion Joint demised Parking Deck at Condo building. Expansion joint transitions are welded and watertight in THERMAFLEX from EMSEAL. Expansion joints water tested to ensure no leaks at plane and direction changes.
(click images for larger view)
Expansion joints for parking decks (above left) are often the leak point for water into lower level parking areas or even occupied space below.  Watertightness is therefore critical.  When design or structural factors cause joints to change plane or direction is where most joints leak--often after the first rain storm.  EMSEAL uses a thermoplastic rubber in the manufacture of our THERMAFLEX parking deck expansion joint system.  This allows the joint to be factory-welded to follow changes in plane and direction while preserving continuity of seal (above middle). While others have adopted the raw material to be able to offer this feature, few make it the cornerstone of their practice.  In addition, EMSEAL is the only manufacturer that routinely reinforces all factory welds with an additional layer of thermoplastic rubber sheet.  By doing so the full uncut strength of the rubber is restored at all welds. 

Anyone can make joints watertight in cross-section.  But expansion joints exist in 3-D. Where they jog around columns; go up a curb and over a sidewalk; or terminate into a vertical plane surface like a wall or parapet, is where expansion joints leak.  Water tests (above right) should be a standard to ensure that installation of transitions is watertight as well.

Posted January 18th, 2010

UVA's Scott Stadium Joins Packers, Redskins, Colts, Jets/Giants, and many more in Successful Expansion Joint Installation

Looking down on stadium expansion joint transition from upper to lower bowl.  SEISMIC JOINT SYSTEM from EMSEAL UVA Scott Stadium at time of SEISMIC JOINT SYSTEM installation. SEISMIC JOINT SYSTEM from EMSEAL in treads and risers viewed looking down the seating bowl.
(click images for larger view)

Over the last several years, EMSEAL and contractor Richmond Primoid, Inc. have been involved in a steady program of upgrades to Scott Stadium that includes retrofitting failed and leaking expansion joints.  The program has been flexibly adapted to the university's sports schedule as well as annual budgets.

The custom-tailored solution takes into account the locations, traffic, movement, and existing joint sizes at each expansion joint location.  Consequently systems from EMSEAL's entire selection of stadium expansion joints have been utilized where they are best suited.  SEISMIC JOINT SYSTEM-SJS is the latest to be installed and was chose where existing joints were too large for a winged-compression seal system like THERMAFLEX that was used elsewhere on the project.

The picture above left illustrates the unique ability of SJS to ensure continuity of seal in plane changes. The view is looking down over the railing at the transition between the upper and lower seating bowls.  It shows how the expansion joint system has been supplied and installed to be watertight throughout this transition.

Above right is a view looking down the completed installation of the SJS SYSTEM in the seating bowl.  The sandblasted coverplates are skid resistant and feature a long chamfer on its edges to facilitate pedestrian traffic.  Other EMSEAL systems used on the project include double-sided SEISMIC COLORSEAL, DSM SYSTEM, SEISMIC COLORSEAL and THERMAFLEX with hundreds of factory-fabricated inside and outside transitions to follow the treads and risers.

Scott Stadium joins the Packers, Colts, Jets/Giants, Patriots, Yankees, Mets, Phillies, U of Michigan, U of Minnesota, U of Maryland, U of Cincinnati and many more on a long list of successful new and retrofit stadium expansion joint projects featuring EMSEAL expansion joint products and custom solutions.

Posted January 15th, 2010 Lester Hensley

Fire-Rated Expansion Joint Sealants Selling Like Hot Cakes

Over 11,000 LF in first year of product launch proves EMSEAL’s fire-rated hybrids are the state-of-the-art of joint sealing.

From prisons to factories, military bases to schools, and airports to stadiums the EMSHIELD product line is combining life-safety, sound blocking and insulation with the traditional roles of sealants in filling and sealing structural and other joint openings.

When we launched our DFR2 (for floors and decks) and WFR2 (for concrete and gypsum walls) versions of our EMSHIELD product line, we knew that the years of R&D in addressing the shortcomings of other technologies had been achieved.  We are hugely gratified by the market response to the product in the less-than-one year since their launch. 

Today’s wall and floor systems are being designed and constructed to perform a growing number of functions. Beyond simply separating rooms or enclosing a structure, they are now expected to maintain thermal conditions, contain the spread of fire, suppress the transmission of sound, and seal out the intrusion of water and wind.

The bottom line: why wouldn’t you specify and install a product with an inherent UL 2079 certified fire rating?  There is no reason to compromise life safety while at the same time satisfying ALL of the functions of the wall or floor assembly into which the product is installed.

EMSHIELD Installation is straightforward with no invasive anchors...
EMSHIELD WFR2, fire-rated expansion joint, is supplied in precompressed 'sticks'. Fire rated expansion joint is removed from packaging. Fire-rated expansoin joint installs easily into joint.
EMSHIELD is shipped precompressed to less than the field measured joint size and held that way in shrink-wrapped, hardboard packaging. The shrink-wrap and hardboard are removed and the foam begins to gradually expand.  Epoxy is applied to the foam and substrate. The WFR2 material is installed into the joint and connected to previously installed lengths or to factory-fabricated transitions.
(for a .pdf of complete installation instructions Click Here)
Posted January 13th, 2010

EMSEAL Goes Deep on Expansion Joints for Massive Port Allen Lock Project


Expansion joints in river locks treated with EMSEAL. Expansion joint retrofit of river locks.

Imagine having to replace and install expansion joints in a massive public works structure with a very small window of time to complete the job. A temporarily drained river lock with concrete walls rising over six stories tall, a bottom bed as wide as half the width of an NFL football field, and four weeks to complete the project before the 90-ton doors reopen to let the Mississippi river water flow back in, was the challenge facing the crews working on the Port Allen (LA) Lock in the summer of 2009.

Built and maintained by the US Army Corps of Engineers, the Port Allen Lock is a crucial connection of shipping traffic between the Mississippi river and the Intercoastal Waterway just west of Baton Rouge, LA. In 2009 it was determined that, due to leak-induced water-related subsidence, the 22 runs of expansion joints (each over 300 feet long) had to be replaced. The plan was to drain the lock and leave it closed for repairs during a four week period. The substantial effect on shipping traffic was secondary to the need to stop the erosion and leaking at the Lock.

Python Corporation of Lacombe, LA was contracted to replace the expansion joints. They contacted EMSEAL with an immediate request for over 6,700 feet of EMSEAL’s DSM to be used as the
surface-seal and a containment barrier for an injected polyurethane grout system. The sealing performance of DSM acrylic-impregnated preformed foam was the determining factor in choosing this product to replace the existing failed caulking. But sealing performance had to also work with the project constraints requiring quick installation and availability of product.
Expansion joint retrofit begins with removal of failed sealants.
Prepared Joint                        DSM Installed

The DSM System, as well as all other EMSEAL preformed foam sealants, is able to be put in place quickly because its non-invasive installation design utilizes the foam’s backpressure to firmly hold the DSM in place within the joint gap. The substrate is simply re-smoothed, cleaned and prepared with an epoxy adhesive and the DSM System is then installed into the gap.

EMSEAL also had to meet a quick engineering and production timetable to work within the four week installation period. EMSEAL’s large manufacturing plant focused their output on quickly turning out the sizable quantity of DSM. Because there were variations of widths within the gaps throughout the Lock, each length was manufactured at a predetermined width and labeled for specific locations to make the installation move as quickly and correctly as possible.

The entire project proved to be a great success. The complete DSM order was manufactured and delivered on time and the installation went quickly enough to finish ahead of the Army Corps of Engineers’ schedule. The Port Allen Lock project illustrates EMSEAL’s unique suitability and popularity in large public works projects

Posted December 16, 2009
Lester Hensley



Answering the Challenge of Watertight Transitions at Canadian Hospital

Hospital parking expansion joints get EMSEAL.
Transitions in expansion joints are often a weakness of the best engineering designs. When executed in the field they dramatically slow the installation process and are often the focus of a failing waterseal. The best solution is having factory-fabricated transitions built into the expansion system before it arrives at the jobsite. This approach to manufacturing is in place at the expanded construction taking place at North York General Hospital in Toronto Canada.

The hospital's new additions included the construction of a large parking structure to handle the growing patient and staff population. The finished project had to be watertight while handling the movements of a large concrete structure in the extreme thermal conditions found in Toronto. Expansion gaps were engineered into the designs and EMSEAL's Thermaflex product line of watertight membrane/nosing systems was chosen as the expansion joint throughout the parking decks. 

Over 1500 feet of
TCR-500, TCR-400 and TCR-300 was specified and installed. Much of this length required transitions and turns to address the unique characteristics of this parking garage with columns, multiple decks and intersecting walls, parapets and roofs. To maintain the integrity and watertightness of the system, EMSEAL factory-fabricated the almost 100 transitions involved in the system. Deck to wall, wall to wall and deck to deck changes in direction and plane were all built into the system at EMSEAL's Westborough, MA factory.

Especially noteworthy are transitions where different widths of sealant join together. At North York General Hospital the differing gap widths demanded that north-south expansion gaps require TCR-500 and east-west gaps require the narrower TCR-400 or TCR-300. Each turn and tee necessitated joining materials of different widths--all successfully completed in the EMSEAL factory. The final system was delivered as a series of lengths of membranes with transitions prefabricated and ready to be installed.

Factory-fabricated tee transition

Close-up of join at TCR-300 to TCR-500

Reverse deck-to-wall vertical transition used at support column

Posted November 2, 2009


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EMSEAL LLC. 120 Carrier Drive, Toronto, ON M9W 5R1



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