Fluid-Applied Membranes and Roof Restoration Methods

Cold-process fluid-applied systems combine the elastic properties of rubber polymers with the waterproofing characteristics of a highly refined emulsified asphalt. The result is a monolithic, seamless rubber membrane. Photos: Paragon Roofing Technology

Fluid-applied membrane systems have been available on the U.S. commercial waterproofing market for many years. Originally, the systems most frequently applied were hot-applied emulsions with or without reinforcements. In the early 2000s, a liquid rubber membrane system was developed that could be applied in cold-process fluid-applied applications. The liquid rubber material combines the elastic properties of rubber polymers with the weatherproof/waterproof characteristics of a highly refined emulsified asphalt. The resulting formulations are proprietary materials that, when properly applied, adhere to form a monolithic rubber membrane. The resulting membrane can be applied to range from 20 mils to 200 mils dry.

Unlike coatings that only provide a film surface or adhesives that require reinforcements for waterproofing capacity, the liquid rubber forms a seamless membrane that provides instant  waterproofing/weatherproofing capabilities. The material cures within seconds to 80 percent of its full strength with full cure within 12 hours of application. The liquid rubber membrane is manufactured at the point of application through its dual component formulation; the system consists of a spray grade and a catalyst that are mixed together at the moment of application through specially designed spray rig equipment. The chemical reaction between the spray grade and the catalyst results in an instant, seamless rubber membrane. The instant set allows the seamless membrane to be in direct contact with water immediately. This feature also allows for the material to be applied either horizontally or vertically up to 200 mils thick in one application. Although the membrane still requires time to fully cure, it is approximately 80 percent cured when the two materials come into contact. This is a unique feature of the material, and it requires specialized equipment and training to be applied correctly.

Advantages of Liquid Rubber Membranes

The dual component formulation consists of a spray grade and a catalyst that are mixed together at the moment of application using specially designed spray equipment. Products are also available in one-part emulsions for application with brushes and rollers.

Liquid rubber membranes combine the properties of adhesives and coatings while adding significant technological advancements that create an instant-setting waterproofing/weatherproofing membrane. It is the 21st century version of a built-up roof (BUR) system that has the performance characteristics of modified bitumen and—because it is a monolithic, seamless membrane—it provides a longer service life with less maintenance than other options. Liquid rubber membranes provide economical solutions to almost all roofing and waterproofing/weatherproofing applications and offer excellent performance characteristics.

The primary advantages of the material are as follows:

· Superior elongation and recovery. Structures move. Surfaces expand. Seasonal temperature changes alter the size and shape of every object. Liquid rubber membranes have the capacity to stretch and recover, which allows for movement of the underlying surface. The average elongation is over 1,000 percent, and the material recovers to 90 percent of its original state after elongation.

· Excellent adhesion. Liquid rubber bonds to most substrates and forms a permanent bond with itself, resulting in self-healing and self-sealing properties. The liquid rubber membrane provides excellent adhesion to metal, wood, plastic, and concrete — even green concrete. It also provides strong adhesion to existing construction materials like BUR, modified bitumen, thermosets and thermoplastic membranes, and all waterproofing materials. In most cases, no primer or tack coat is required.

· Sustainable and environmentally responsible. The materials contain no VOCs and satisfy EPA regulations and environmental concerns. No special ventilation is required, as the material is non-toxic, odorless, and non-flammable.

· Safe applications. Products are available that can be applied with trowels or squeegees as well as a specially designed dual-component spray rig. No heat, kettles, torches or open flames are required in the application process. The material is safe to apply and poses no health risks to the applicators.

Another advantage of the liquid-applied system is that the material is self-leveling. This allows the membrane to conform to substrate irregularities and provide a continuous seal at penetrations, which are typically the most difficult details in roofing applications.

Another primary advantage of the liquid rubber membrane system is that the material is self-leveling. This allows the membrane to conform to substrate irregularities and provide a continuous seal at penetrations, which are typically the most difficult details in roofing applications. The instant, full adhesion of the membrane allows for continuous system application without additional components that would be required with other membrane applications. This eliminates the chances of deformation from the breakdown of different material system components. It also eliminates some of the application errors associated with multi-component systems.

Deformations of one of the materials in the multi-component system can lead to failure of the total system. Examples of typical defects in roofing systems include loss of attachment from improper adhesive application at substrate, insulation or membrane; improperly aligned insulation; loss of attachment of insulation due to substrate irregularities; voids in membrane attachment that lead to blisters and/or ridges; and slumping or buckling flashing due to improper attachment. The improper attachment of one component leads to differential movement in the system.

Liquid-applied systems form a monolithic membrane, eliminating the most vulnerable point of rolled membranes for moisture infiltration: the seams. The superior adhesion characteristics to all types of substrates and materials also eliminates the chances of moisture infiltration under the membrane.

While overspray is minimized in liquid rubber membrane applications, precautions should still be set at perimeter building locations and application should not be attempted in high winds.

The elongation and flexibility of liquid rubber membrane exceeds industry standards. This allows it to withstand typical thermal cycling and perform well in extreme heat and cold. Application temperatures are wider than most other adhesives and coatings, and range from ambient outside temperatures of 20 degrees Fahrenheit to over 100 degrees. The membrane is naturally UV resistant and can be exposed throughout the lifetime of the membrane. The membrane is compatible with all types of reflective coatings if application is required. Granule surfacing can also be applied.

The membrane is also very durable. Depending on applied dry mil thickness, the membrane can withstand heavy force and is puncture resistant with self-healing and self-sealing properties.

The membrane can be applied over damp surfaces and it can be exposed to ponded water in unlimited duration. The material has been used as pond liners and in containment tanks since its introduction to the market. The water absorption rate is less than 1 percent—well below ASTM’s minimum water absorption rate of waterproofing materials, which is 5 percent.

Benefits for Applicators

There are significant benefits to applicators of liquid rubber membranes. The foremost benefit is the reduced crew size required for application. This is an important consideration due to the severe labor shortages affecting the construction industry.

In most cases, a crew of three properly trained and experienced applicators using one spray rig can complete up to 10,000 square feet in one day. Additional hoses and/or spray rigs can double or triple those production rates.

In addition to the advancements in material technology, there are vast improvements to the specialized equipment used in the application process. The spray equipment is now portable and can be transported to construction sites without heavy trucks and covered trailers. The spray equipment is also lightweight and can be easily positioned on roof areas or waterproofing trenches. This equipment is housed on four-wheel carts for easy transport throughout the construction site.

The spray equipment consists of a high-volume, low-pressure system. The dual component equipment mixes the two components outside the gun to form a monolithic membrane upon impact with the substrate.

The equipment has a direct drive system to eliminate downtime associated with traditional belt drive systems. The application rate averages up to 1,000 square feet an hour for one gun. The equipment can run two guns at the same time, which increases production to 2,000 square-feet per hour. It can run up to 600 feet of hose and the material can be contained in everything from a 5-gallon pail to a 275-gallon tote. The most common container is a 55-gallon drum.

The spray guns have also improved. Advancements in manufacturing have eliminated most of the clogging issues that plagued spray guns in the past. The spray guns are lightweight and can be disassembled rapidly if material clogs occur. The older spray guns took up to an hour to take apart in the event of material clogs.

Overspray—a common problem with most spray applications—is minimized in liquid rubber membrane applications because it is a low-pressure application and the material cures instantly after release from the spray gun. Precautions, such as coverboards, should still be set at perimeter building locations and application should not be attempted in accelerated wind conditions, but the chances of excessive overspray are minimal.

Liquid Membranes and Roof Restoration

Because of their waterproofing/weatherproofing capacity, instant cure set, adhesion success with most substrates and materials, wide range of application temperatures and membrane mil thickness that can range from 20 mils to 200 mils dry, liquid rubber membranes can perform in most building exterior applications, including new and remedial roofing applications. At this time, the systems are being used primarily as roof restoration and repair products.

Typical roof restoration projects include applications over built-up roof systems (asphalt and coal-tar), thermoplastics, EPDM, sprayed polyurethane foam, metal and tile. The liquid rubber membrane systems were designed to significantly extend the service life of the existing roof system. They are also excellent for repairing flashings and penetrations. The spray equipment is small and mobile and most repairs can be completed with minimal manpower.

When it is applied by knowledgeable installers, the system is an excellent economical choice for building owners. The initial step in the restoration process is the proper repair of the existing roof system and preparation of the surfaces. All surfaces should be free from any loose dust, debris, oil, grease or foreign material. These items should be removed prior to application by means recommended by the manufacturer. The liquid rubber membrane can be applied over damp surfaces; however, extensive ponding water should be removed prior to application.

Proper roof repairs should be completed in compliance with roofing industry standards. The one-part emulsion can be used for repairs to the existing membrane. Reinforcements should be added as required. All cracks, penetrations, existing seams, corners should be addressed using polyester fabric with roller/brush or trowel grade.

Once proper repairs and preparation are completed, the liquid applied membrane can be applied to the existing roof surface. For most roof membranes and substrates, a light rinse/power wash of the surface is all that is required. A primer is required over existing EPDM membranes.

The other exception is on aggregate surfaced built-up roof systems, which require additional preparation. Removal of all loose aggregate is required. On asphalt-based BUR, the liquid applied membrane can be applied directly over the prepared surface. For coal-tar based BUR, a manufacturer-approved fabric is required due to the gassing of the coal tar. The reinforcement should be set in a 20-mil wet profile of one-part liquid rubber. The reinforcement shall be set in a full and even application so that it is fully adhered with no wrinkles, buckles or blisters. The liquid rubber membrane is then set over the reinforcement. For best application practices, the reinforcement should be set in place with a soft-bristle broom.

The application of moisture relief vents is also required on BUR systems to prevent gassing of bitumen, which could contribute to blisters. Typical applications require one vent for every 1,000 square feet. Additional vents may be used in areas with existing moisture in the system.

Once the preparation and proper repairs have been completed, the liquid rubber membrane can be applied. Application can be completed with brush, roller or trowel in smaller application areas. Spray grade material shall be applied using specialized equipment. Apply material in a full and even application. Always apply it in strict accordance with manufacturer’s recommendations and approved submittals.

Stir materials during application in accordance with manufacturer’s instructions to avoid product separation. Applicators should spray the fluid component as a continuous, monolithic and seamless membrane of uniform thickness, beginning at the lowest point and terminating at the highest point. In the event the membrane is applied too thin, contact the manufacturer for recoating guidelines. Prior to application, create a grid across the roof with spray paint, allocating one drum of material per section of the grid. Perform cut-outs to check mil thickness and retain samples. Typically, three test cuts are to be taken per 1,000 square feet. In addition, continuously check wet millage by using the “T” post on a caliper mil gauge. After the liquid rubber membrane has cured, apply trowel adhesive to any visible voids. Comply with the manufacturer’s recommendations for proper membrane terminations.

For horizontal applications, apply the two-part liquid rubber membrane in a single, monolithic coat to minimum 80 mils wet/60 mil dry. Repair damaged installation in accordance with manufacturer’s requirements. The spray application requires a 90-degree spray angle (a golf putting motion) with the spray tip within two feet of the surface. Wider spray angles will decrease mil thickness and can cause uneven application.

Ultraviolet stabilizers are added into the material formulation so the completed liquid applied membrane does not require additional surfacing for UV protection for short term (less than ten years) exposure. Long-term exposure (and warranties) require that some sort of surfacing is applied for additional reflectivity or protection. A variety of surfacing materials, including coatings, granules, pavers and living roof applications can be applied.

Liquid-applied membranes are typically eligible for warranties from 10 to 25 years. Contact the manufacturer for warranty requirements.

About the author: John A. D’Annunzio is the owner of Paragon Roofing Technology, headquartered in Troy, Michigan. He has been involved in testing, evaluating, and designing roofing and waterproofing materials and systems for more than 30 years. For more information, visit www.paragonroofingtech.com.

The Hatch Memorial Shell Shows Off New Roof at 4th of July Celebration

The Boston Pops perform at The Hatch Memorial Shell on July 4, 2018. Photo: Walter Mulligan Photography

The Boston Pops perform at The Hatch Memorial Shell on July 4, 2018. Photo: Walter Mulligan Photography

In an annual tradition, Boston kicks off its outdoor summer concert series with a nationally televised performance by The Boston Pops Orchestra on the 4thof July while fireworks snap and sparkle. The Pops perform from The Hatch Memorial Shell, an amphitheater shaped like the quarter of an orange that opens to the crowd on the Charles River Esplanade.

The difficulty of waterproofing this curved structure became apparent after the Massachusetts Department of Conservation & Recreation (DCR), owner and manager of the Hatch Shell put out a bid for a new roof around Labor Day in 2017. The specification called for a single-ply EPDM sheet with pre-cast concrete panels set atop pedestals as an aesthetic outer shell.

Folan Waterproofing & Construction Co. Inc. of South Easton, Massachusetts, the general contractor, handled the overall project as well as demolition of an old terrazzo roof and installation of the new pre-cast concrete panels. Executive manager Patrick Folan worked closely with roofing contractor John F. Shea Company of Mattapan, Massachusetts, which was responsible for the waterproofing installation.

Working from cloud point data, lasers marked the position of the 1,476 pedestals that would hold the 3-inch thick concrete panels in place on the curved structure. Photo: Kemper System America Inc.

Shea Company project manager Michael Frank, RRC, reviewed the installation challenges with Folan. The EPDM sheet would need to be cut into multiple slices, and then require full adhesion to the curved roof deck as well as along all the lap seams. The pedestals for the 665 concrete panels also posed an issue since the anchor studs would penetrate the EPDM sheet. There would be nearly 4,500 penetrations on the job for the 1,476 stainless steel pedestals alone. No EPDM manufacturer would warrant the installation.

After the contract was awarded in October 2017, the construction team suggested an alternative inspired by a recent project for a youth center in Cambridge. There Shea Company used the Kemperol 2K-PUR liquid-applied reinforced membrane system to waterproof below a plaza deck topped with pedestals and pavers. The DCR and Boston architectural firm Bargmann Hendrie + Archetype Inc. gave the team a green light to explore further.

“The point we made was that because we are dealing with such an odd shape and with so many penetrations for the studs, it would be much easier to install the Kemperol liquid-applied system,” Frank says. “With the single-ply EPDM sheet, there would be ‘miles’ of field seams and, of course, every time you have a lap joint, you have areas that may be suspect at some point for leaking.”

The team contacted Kemperol manufacturer, Kemper System America Inc. of West Seneca, New York, and detailed specifications for the assembly along with cost estimates were presented to the owner and architect about two weeks later. “Obviously, there was a change in installed cost, but it was almost immediately accepted. So, we needed to completely shift gears, and revise our shop drawings and submittals accordingly,” Frank says. Among other things, the design of the stainless steel pedestals was modified to allow the panels to rest a couple of inches above the new reinforced membrane.

Air hammers were used to remove the aging terrazzo and concrete layer. Photo: Kemper System America Inc.

The surface preparation for the waterproofing started in April 2018, with a late May project completion target. The Folan crew removed the old cast-in-place terrazzo roofing system with air hammers and then peeled back an existing neoprene membrane to expose the structural concrete deck. Before the waterproofing membrane could be applied, Folan completely tented the roof with winter enclosures around the scaffolding, and then added diesel heaters to maintain the temperature above 40 degrees F.

Shea Company worked the job across the top of the structure and down row-by-row. After applying a Kempertec EP primer, crews applied Kemperol 2K-PUR resin with high-nap rollers a section at a time while laying Kemperol reinforcement into the resin from 20-foot rolls. Each roll was pre-cut lengthwise and then rerolled so it could be smoothly laid onto the curved surface. This was closely followed by a topcoat of the resin to fully embed the reinforcement in the resin. The system fully adheres to the deck and creates a monolithic watertight surface.

Securing the Anchors

Each pedestal needed to be precisely positioned and anchored into place through the membrane, so the epoxy anchoring system for the studs was key to the project.

The team from John F. Shea Company waterproofed the concrete roof deck with a Kemperol liquid-applied reinforced membrane system. Photo: Kemper System America Inc.

The team from John F. Shea Company waterproofed the concrete roof deck with a Kemperol liquid-applied reinforced membrane system. Photo: Kemper System America Inc.

After the membrane fully cured, 3-D measurements were taken across the dome with point cloud software to help determine the height difference between the surface of the membrane and the desired finished elevation for the pre-cast panels. The surveying firm that made the measurements returned when it was time to set the pedestals.

“Their surveyors marked out the dome with lasers. They would set a mark, and say, ‘This is your point for four panels, and this is the cavity depth for the finished panel elevation,’” Folan explains. There was also GPR (Ground Penetrating Radar) scanning performed to locate existing reinforcement in the original structural concrete. His firm carefully drilled holes for the threaded studs to avoid the existing reinforcing steel, and the studs were then set in epoxy. Shea Company then applied GreatSeal PE-150 sealant around the pedestals and the heads of the bolts.

“Kemper System provided this detail, and they wanted the epoxy to ooze out of the pre-drilled holes when the anchors were inserted,” he says. “We would then hang the pedestals on the studs, and screw nuts onto the studs to hold the pedestal in place.”

The Folan team needed to wait for an architectural review of the pre-cast concrete panels before they could be installed. They were not all the same, but designed and numbered like puzzle pieces for their location on the shell. The 3-inch thick panels averaged 3 feet by 4 feet, and needed to be lowered by crane since they ranged from about 350 to 550 pounds each.

The studs for the pedestals were epoxied in place through the Kemperol membrane and top-sealed with GreatSeal construction sealant, also from Kemper System. Photo: Kemper System America Inc.

The panels were installed row-by-row starting at the bottom with 3/4-inch open joints between. “The biggest factor at that point was the depth of the cavity. Before we set a pedestal, we needed to know whether it should be shimmed 1/16th, 1/8th or 1/4 inch,” Folan says.

Though the panel fabrication process started late, the team worked six days a week with some 10-hour days to complete the job by a final June 15thdeadline. “As fast as they could get us the pre-cast panels, we were putting them in,” he recalls.

Looking back, Folan says the pedestals would have required much more time to install if the Kemperol system had not been selected, since there were nearly 1,500 of them and each would need to be covered with EPDM. “With the Kemper System detail, we could just keep moving to meet the deadline in time for the big July 4thcelebration.”

TEAM

Architect: Bargmann Hendrie + Archetype Inc., Boston, https://bhplus.com
General Contractor: Folan Waterproofing & Construction Co. Inc., South Easton, Massachusetts, www.folanwaterproofing.com
Roofing Contractor: John F. Shea Company of Mattapan, Massachusetts, www.johnfshea.com

MATERIALS

Liquid-Applied Waterproofing System: Kemperol 2K-PUR liquid-applied reinforced membrane system, Kemper System America Inc., West Seneca, New York, www.kemper-system.com

New Elastomeric Acrylic Silicone Waterproofing Roof Coating

Nationwide Protective Coatings Mfrs.Inc. announced its latest product to the PERMAPRODUCT Line. Introducing PERMASIL, the New Silicone infused Bright White Elastomeric Acrylic, Ceramic Insulating, Waterproofing Protective Roof Coating with a 15-Year Warranty. A water-based Energy Saving high build formula that beautifies, protects and extends the life of most any roofing surface, according to the company. Silicone Technology adds extra waterproofing protection by sheeting off water from the dried coating surface. Easy to apply and will provide many years of durable protection, outstanding beauty and will extend the roof’s life. An inexpensive alternative solution to re-roofing.

For more information, visit nationwidecoatings.com.

Water Seal Waterproofing Treatment for Use on Brick and Concrete

New Mortar Sentry Water Seal waterproofing treatment from Mule-Hide Products Co. produces a water-repellant surface on masonry and concrete, extending the service lives of chimneys, walls and other surfaces.

Mortar Sentry is designed for use on alkaline materials, including brick, mortar, concrete block, cultured stone, sandstone and concrete. It can be applied to horizontal and vertical surfaces. It is not recommended for use on non-silicate natural stone, such as limestone or dolomite.

Mortar Sentry penetrates below the surface of brick and concrete, chemically reacting with the alkalines and silicas there to create a barrier that locks moisture out while allowing trapped moisture to escape. In brick structures, this waterproofing reduces the movement cracks caused when bricks absorb moisture and expand. In concrete structures, it helps prevent the accelerated aging caused when trapped moisture freezes during the winter or is exposed to high summer temperatures.

The treatment also helps prevent the rusting of concrete reinforcement, protects against the growth of mold and mildew, and eliminates the primary cause of efflorescence – the white powder left on brick and concrete when trapped water evaporates and leaves behind deposits of dissolved salts.

Because Mortar Sentry saturates brick and masonry – rather than simply leaving a film on the surface – it does not wear away when exposed to the elements. The original color and texture of the surface are retained.

Mortar Sentry is easily applied using a low-pressure, garden-type sprayer or a brush or roller.

The line includes two formulas. Mortar Sentry Water Seal 10 is recommended for use on vertical surfaces. Mortar Sentry Water Seal 15 provides the additional durability that horizontal surfaces require.

Both Mortar Sentry products are packaged in 1-gallon jugs and 5-gallon pails.

For more information, visit www.mulehide.com.

 

Drain Mat Developed for Use in Balconies and Breezeways

TAMKO’s new TW-Drain 220TAMKO’s new TW-Drain 220 is a drain mat designed with core and fabric construction to help keep water out of residential, multifamily and light commercial projects. According to the company, the drain’s unique design allows for quick and simple installation in concrete waterproofing projects.

TW-Drain 220 may be used for above grade applications such as balcony/breezeways. TW-Drain 220’s dimpled drainage core and filter fabric help protect entry points from potential moisture penetration into buildings.

“With TAMKO’s TW-Drain 220, water flows through the dimpled core, rather than building up excess moisture within the concrete. This relieves hydrostatic pressure and leads to better protection for your project,” said Corporate Director of Waterproofing for TAMKO, Brandon Knobloch.
TW-Drain 220 comes in 50-foot rolls with a 4-foot width. TW-Drain 220 can be purchased now from TAMKO’s Columbus, Kansas manufacturing facility with nationwide availability. Mixed truckload orders may be placed with TAMKO’s extensive line of additional waterproofing products.
For more information, visit TAMKOWaterproofing.com.

Polyglass Achieves ISO 9001:2015 Certification

Polyglass U.S.A., Inc. announced that it has achieved ISO 9001:2015 certification. This accomplishment validates Polyglass’ commitment to manufacturing quality roofing and waterproofing products, enhancing customer satisfaction, and improving business performance.

“We are proud to receive ISO 9001:2015 for all of our Polyglass locations,” said Polyglass CEO Natalino Zanchetta.  “As a quality-focused company, implementing a Quality Management System is a natural step for Polyglass. It increases our reputation for quality products in the industry and builds trust and confidence in our brand.”

Certification to ISO 9001 requires an accredited registrar (third-party auditing organization) to thoroughly review the company’s policies, processes, and procedures to ensure that they are capable of consistently meeting customer, regulatory requirements and the intent of the ISO 9001:2015 standard.

The ISO 9001 standards are published by the International Organization for Standardization, an international agency composed of the national standards bodies of more than 160 countries. A new version of the ISO 9001 appears about every seven years to ensure organizations continue to adapt to the changing environment in which they operate. ISO 9001:2015 is the latest of the ISO 9001 international standards.

For more information, visit www.polyglass.us.

RCI Canadian Building Envelope Technology Symposium Call for Abstracts

RCI, Inc. is excited to announce the first ever RCI Canadian Building Envelope Technology Symposium. The symposium will take place September 13-14, 2018, at the Hilton Mississauga/Meadowvale, Mississauga, ON.

We are now accepting abstracts for papers to be presented at the Canadian Building Envelope Technology Symposium. Abstracts of each paper (200 words) should be received at RCI headquarters by April 13, 2018. The RCI Canadian Building Envelope Technology Symposium Committee will review abstracts, and authors will be notified regarding acceptance of abstracts by April 20, 2018. If accepted, papers should be received by May 25, 2018, for peer review.

Potential authors should contact Tina Hughes at RCI headquarters for a copy of the Abstract Submittal Form and RCI Guidelines for Presentations, complete directions on formatting, and acceptable formats for abstracts and papers. A topic description must be provided addressing the speaker’s subject knowledge and the level of knowledge that will be presented to the attendee (i.e., beginner, intermediate or advanced). Six RCI CEHs will be granted for an accepted paper. Additionally, presenters will earn triple credit for the length of the program (one presentation hour yields three CEHs).

Download the 2018 RCI CBES Call for Abstracts PDF for more details.
Suggested topics include:

  • Innovative Technologies & Practices
  • Façade Systems & Technologies
  • Unique Façade Design Solutions
  • The Building Envelope as a Design Statement
  • Energy Conservation Design
  • Designing Façades That Will Improve Indoor Air Quality
  • Economics & Life Cycle Analysis
  • Panelized Stone or Masonry Systems
  • Sealants – Design & Selection / Appropriate Specifications / Quality Assurance
  • Hygrothermal Analysis in Façade Designs
  • Façades Designed to Achieve Sustainability
  • Unique Detail Design Work
  • Curtainwalls
  • Double-Wall Façades
  • Roofing
  • Brick Masonry
  • Stone Masonry
  • Waterproofing
  • Stucco
  • EIFS
  • Metal Wall Panels
  • Air-Barrier Systems
  • Testing Wall Systems
  • Construction Processes

For more information, visit http://rci-online.org.

Metal Roof and Wall Panels Capture the Spirit of Shakespearean Theater

The Otto M. Budig Theater is the home of the Cincinnati Shakespeare Company. The new theater was designed by GBBN Architects in Cincinnati. Photos: Petersen Aluminum Corp

For many new arenas and theaters, the sheer size and scope of the project can pose the biggest hurdles. At the new Otto M. Budig Theater, home of the Cincinnati Shakespeare Company, the problem was the reverse. The intimate theater was shoehorned into an existing space up against an adjacent building, so logistics were tight. But that didn’t mean the roof system couldn’t be striking. Designed by GBBN Architects in Cincinnati, the building’s exterior features daring angles and multi-colored metal roof and wall panels that combine to help capture the spirit of the Shakespearean theater.

Matt Gennett, senior project manager and vice president of Tecta America Zero Company in Cincinnati, oversaw the roofing portion of the new construction project in the Over the Rhine section of Cincinnati on the corner of Elm Street and 12th Street. “This building was plugged in downtown, and they fit everything in real tight,” he says.

Approximately 5,400 square feet of PAC-CLAD 7/8-inch, 24-gauge Corrugated Panels from Petersen Aluminum Corp. were installed on the metal roofs and walls. Tecta America Zero Company installed the metal roof systems, as well as a TPO roof manufactured by Carlisle SynTec over the main structure and mechanical well. Work began in January of 2017 and the roofing portion of the project was wrapped up in late August.

The Metal Roof System

The building features two different metal roof systems. The roof on the Elm Street side is comprised of three intersecting triangle-shaped sections in two colors, Champagne Metallic and Custom Metallic Bronze. “There were several unique angles on the roof,” Gennett explains. “On the top, there was a second metal roof, a shed roof that went down to the 12th Street side.”

The theater’s roof and walls feature approximately 5,400 square feet of PAC-CLAD 7/8-inch Corrugated Panels from Petersen Aluminum Corp. in two colors. The wall panels are perforated. Photos: Petersen Aluminum Corp.

The metal roof systems were installed over a 2-inch layer of polyisocyanurate insulation and a 2-1/2-inch nail base from Hunter Panels, H-Shield NB. The nail base is a composite panel with a closed-cell polyisocyanurate foam core, a fiber-reinforced facer on one side and, in this case, 7⁄16-inch oriented strand board (OSB) on the other. The nail base was topped with Carlisle WIP 300 HT waterproofing underlayment to dry in the roof.

Crews also installed two rows of snow guards on the metal roof using the S-5! CorruBracket. “The snow guard was a little different,” Gennett says. “It was specifically designed for a corrugated roof.”

The TPO Roof System

The main roof and mechanical well were covered with the TPO roof system, which totaled approximately 8,300 square feet. After Carlisle VapAir Seal725 TR self-adhering air and vapor barrier was applied to the metal deck, crews installed two layers of 2-inch iso. Tapered insulation was applied over the top to ensure proper drainage. The insulation was covered with a 1/2-inch sheetrock and the 60-mil TPO was fully adhered.

Two large smoke hatches manufactured by Bilco were installed over the stage area. The ACDSH smoke hatches measured 66 inches by 144 inches, and are designed for theaters, concert halls and other interior applications that require limiting noise intrusion.

The Installation

The initial focus was to get the roof dried in so work could progress inside the building. The jobsite conditions posed a few challenges. The structure abutted an existing building, and the space was tight. The schedule necessitated multiple trips to the site, which can be a budget-buster on a small project. “We had a lot of trips in and out to accommodate the schedule and get everything dried in so they could meet the interior schedule,” notes Gennett. “We were sort of on call. We made three or four trips out to roof this small project, so it took a lot of coordination because it was completed in pieces.”

Crews tackled the TPO roof sections first. The mechanical well section provided several challenges. Changes in the mechanical well layout necessitated moving some curbs and making adjustments to the tapered insulation. “They were trying to get lot of equipment into a small space,” Gennett explains. “We had to make sure we could get the water to the low spots and route it around all of that equipment. That was probably the biggest challenge on the project.”

Staging material was also problematic, as traffic was heavy and parking space was at a premium. Material was loaded by a crane, which had to be set up in the street. “It’s a postage stamp of a site,” says Gennett. “This is a main thoroughfare, and there is a school right across the street. We had to work around school hours, and we couldn’t be working when the busses were coming in. We usually came in after school started, around 8 a.m., to load materials.”

When it came time to load the metal panels, the cramped jobsite actually paid off. “It was very convenient,” Gennett recalls. “We were able to load the panels onto the adjacent roof and just hand them over. We had a nice staging area for cutting, so all in all it wasn’t bad.”

The corrugated panels were installed with matching edge metal. “It’s not a complicated panel to install, and they look really nice,” Gennett notes. “On the Elm Street side, to the right of the valley was one color, and to the left was another, so we had to match the color with our coping. There were some interesting transitions with our metal. We also had to really pay attention to how the siding was being installed so we could match the metal to the siding and follow the transitions from color to color.”

The perforated wall panels were installed by ProCLAD Inc. of Noblesville, Indiana. “Once the walls were done, we came in and did the transition metal,” Gennett says. “We just had to make sure everything lined up perfectly.”

Planning Ahead

Ensuring a safe jobsite was the top priority for Tecta America Zero and Messer Construction, the general contractor on the project. “Both Messer Construction and Tecta America take safety very seriously. That’s why we’re good partners,” Gennett says. “We had PPE, high-visibility clothing, hard hats, safety glasses for the whole project. All of the guys were required to have their OSHA 10. Anyone outside of the safety barriers had to be tied off 100 percent of the time.”

Planning ahead was the key to establishing the safety plan and meeting the schedule while ensuring a top-quality installation. “This job had a lot of in and out, which is tough in the roofing business,” Gennett says. “But we planned ahead, we made sure everything was ready for us when we mobilized, and we did a good job of coordinating with the other trades. It took a lot of meetings and discussions — just good project management.”

Gennett credits the successful installation to a great team effort between everyone involved, including the general contractor, the subcontractors, and the manufacturers. “We pride ourselves on our great, skilled crews and our great field project management,” he says. “Our superintendents are there every day checking the work and making sure the guys have everything they need. Messer Construction is great to work with, and obviously having the manufacturer involved the project and doing their inspections as well helps ensure the quality meets everyone’s standards and holds the warranty.”

The theater is now another exciting venue in the Over the Rhine neighborhood. “It is really cool spot,” Gennett says. “It’s an up-and-coming neighborhood that’s grown in leaps and bounds in the last seven years. There is a ton going on in Cincinnati. It’s just another part of the city that makes it really fun to go downtown.”

TEAM

Architect: GBBN Architects, Cincinnati, Ohio, www.gbbn.com
General Contractor: Messer Construction, Cincinnati, Ohio, www.messer.com
Roofing Contractor: Tecta America Zero Company, Cincinnati, Ohio, www.tectaamerica.com
Wall Panel Installer: ProCLAD Inc., Noblesville, Indiana, www.procladinc.com

MATERIALS

Metal Roof:
Roof Panels: PAC-CLAD 7/8-inch Corrugated Panels, Petersen Aluminum Corp., www.pac-clad.com
Wall Panels: PAC-CLAD 7/8-inch Corrugated Panels, Petersen Aluminum Corp.
Nail Base: H-Shield NB, Hunter Panels, www.HunterPanels.com
Snow Guards: CorruBracket, S-5!, www.S-5.com
Waterproofing Underlayment: Carlisle WIP 300 HT, Carlisle SynTec, www.CarlisleSyntec.com

TPO Roof:
Membrane: 60-mil grey TPO, Carlisle SynTec
Waterproofing Underlayment: Carlisle WIP 300 HT, Carlisle SynTec
Smoke Hatches: ACDSH Acoustical Smoke Hatch, The Bilco Co., www.Bilco.com

North Carolina Legislative Building Restoration Poses Unique Challenges

The North Carolina State Legislative Building was the site of a renovation project that included asbestos abatement in the interior and a complete restoration of the building’s roof systems.

The North Carolina State Legislative Building was the site of a renovation project that included asbestos abatement in the interior and a complete restoration of the building’s roof systems. Photos: SkySite Images

Some of the variables that can make a project difficult include a variety of complex, interconnected systems, unique design elements, and a tight schedule. These challenges are heightened on a highly visible, historic building, where the goal of keeping the design historically accurate must be balanced with making improvements to the structure and functionality of the systems. All of these elements and more were in play during the restoration of the one-of-a-kind roof on the North Carolina State Legislative Building in Raleigh, North Carolina. It took a talented team of design, engineering, and roofing professionals to bring the project to a successful conclusion.

Originally designed by architect Edward Durell Stone, the building has been the home of the state legislature since 1963, but water intrusion under its copper pyramids and at windows and doors on the promenade level precipitated a complete restoration project. Renovation work conducted in 2016 and 2017 included asbestos abatement in the interior and a complete restoration of the building’s roof systems.

The roofing phase of the project included removing and replacing the metal roof systems on the five copper-clad pyramids, as well as re-roofing the low-slope sections adjacent to the pyramids with a two-ply modified bitumen system. A liquid-applied waterproofing system was installed in the planter areas and under the pavers in the promenade section. The project also involved the removal and replacement of windows, doors, and skylights, as well as repairing and coating the concrete surfaces at the perimeter of the roof.

The design of the quilted flat lock copper panel system involved 17 different panel profiles. A false batten was added after the panels were in place.

The design of the quilted flat lock copper panel system involved 17 different panel profiles. A false batten was added after the panels were in place. Photos: SkySite Images

Companies involved in the project included Raymond Engineering, headquartered in Raleigh, North Carolina, which provided engineering and architectural services; Owens Roofing Inc., also located in Raleigh, which served as the general contractor on the roofing phase of the project and installed the low-slope systems; and The Century Slate Company, headquartered in Durham, North Carolina, which removed and replaced the copper roofs on the five pyramids.

Some of the key players in the project shared their insights with Roofing, including John Willers, a senior engineer with Raymond Engineering; Bert Owens, president of Owens Roofing; and Mike Tenoever, president of Century Slate.

“This is an iconic state building with a unique roof system which the owner and designer required to be aesthetically replicated,” Tenoever notes. “At the same time, some functionality and technical improvements were incorporated. This is a very high-profile project with a lot of complexity, particularly given the schedule. There were a lot of details compressed into a very short period of time.”

Design and Pre-Construction

Raymond Engineering conducted testing on the existing roofs and specified systems designed to match the originals and provide some necessary improvements, including added insulation and ventilation under the pyramids. Willers worked closely with Jason Mobraten, the senior architect on the project. “We provided the engineering and architectural services, beginning with design and then assisting with bidding and managing the construction phase of this project,” says Willers. “We engineered the copper roof, all of the detailing for the modified asphalt roof, and the detailing for the drainage, the pavers, and the sealants for the promenade.”

Crews from Owens Roofing removed the existing plants, media and drainage system from four 42-foot-by-42-foot fixed planters with skylights. After the substrate was cleaned and primed, a liquid-applied waterproofing system was installed.

Crews from Owens Roofing removed the existing plants, media and drainage system from four 42-foot-by-42-foot fixed planters with skylights. After the substrate was cleaned and primed, a liquid-applied waterproofing system was installed. Photos: SkySite Images

The schedule was an obvious challenge, as the majority of the work had to be completed while the legislature was in recess, and there were substantial financial penalties that would come into play if the work was not completed on time. “The client also required that the asbestos abatement be completed before re-roofing the copper-clad pyramids to avoid the risk of dislodging the asbestos-containing textured ceiling finish. However, doing the work in two phases allowed the asbestos contractor to get started while the rest of the job was designed and bid,” Willers states.

The building houses legislators’ offices, and it was open and occupied during construction, with the exception of the areas undergoing asbestos abatement. The schedule had to be carefully adjusted as the job progressed. “In addition to our role in monitoring the technical aspects of the construction, we closely monitored the construction phasing and sequencing, as it was directly driven by the schedule of the state legislature,” Willers notes. “We had to take a lot of care in developing the schedule and monitoring it.”

Willers and Mobraten knew that the details on this project would be crucial. “There were previously some issues where the copper and the low-slope membrane roofs met,” Willers says. “We detailed that very carefully so that we had redundancy in keeping that watertight.”

Extensive mock-ups of the copper pyramids were constructed and tested to ensure the quilted pattern could be exactly replicated while avoiding the leaks that plagued the existing structure.

Photos: SkySite Images

Photos: SkySite Images

As designers looked for ways to improve construction, they explored the design and construction of the quilted panels. “From a design standpoint, we wondered why we had this odd diamond-shaped pattern,” Willers recalls. “After we played with the dimensions a bit, we realized that if you fly over the building, from above all of those diamond sections look like squares.”

The key was to replicate the design with its false battens while avoiding leaks. “We were concerned about how to detail out the joining of the copper sheets that formed the diamond-shaped panels,” Willers says. “What had been done was susceptible to windblown rain getting in. We did two things differently: the little clips that supported these battens were secured by forming the clips with hooks that would be integral with the single-locked seams and soldering the clips to the top surface of the copper panels. Previously they were held in place by pop rivets, which went through the copper.”

The Secrets of the Pyramids

Century Slate was well prepared to tackle the copper roofing on the project. The company has been in business more than 20 years, and it specializes in historic restoration projects including slate, tile, wood, copper and other historical metals.

Crews from Century Slate removed the existing copper panels. The copper was salvaged and recycled.

Crews from Century Slate removed the existing copper panels. The copper was salvaged and recycled. Photos: SkySite Images

Tenoever knew the design of the original quilted flat lock copper panel system needed to be replicated exactly. “There were 17 different panel profiles, each within a very particular location within the roof’s quilted pattern,” Tenoever notes. “Proper placement of each different profile was essential to the whole system working correctly and looking like the original.”

The first step was to remove the existing copper roofs. “We tore off the entire system down to the deck,” Tenoever explains. “We then installed a semi permeable a vapor barrier, insulation, and a vapor retarder.”

Along with added insulation and Carlisle WIP 300HT self-adhering underlayment, crews also installed a vented nail base from Hunter Panels. “The Hunter Cool-Vent is a vented nail base that gets screwed down,” Tenoever says. “The goal was to have a breathable air cavity. All of the hip caps are actually vented to allow the air to get out.”

With the addition of the insulation and nail base, the roof was built up approximately 6 inches from the previous configuration. This added height necessitated changes in the custom flashing at the base of the pyramids but did not change the configuration of the copper panels.

In all, 22,500 square feet of copper panels fabricated by K&M Sheet Metal in Durham were installed. Each of the 17 different panels was labeled with a letter code. “When they were out at the site, we could just grab an A panel or a B panel, as needed, and bring them to that layout,” Tenoever explains. “Four of the pyramids were the same, and the center one was different, as that was the one that had skylights built into it.”

The areas between the pyramids were covered with a two-ply modified bitumen roofing system. Photos: SkySite Images

The panels feature flat-lock clips that were screwed down to the nail base. “It’s a typical flat seam panel system, and the panels interlock together,” says Tenoever. “You can see the batten panel above it, which is an aesthetic feature. The battens and the clips that held them were amazingly intricate, for what they were. They were cut out with a CNC machine and soldered onto the copper panels prior to installation. Later we came back and installed the batten system over the top.”

Century Slate built new curbs in the center pyramid for the new skylights, which were manufactured by Wasco. “The skylights were one of the last things to go on,” says Tenoever. “They were custom made because even though they look square, there isn’t a square angle on them.”

Custom copper flashings were installed at the bases. “One of the trickier parts for us probably would have been the tie-in of the modified roof, because Owens Roofing had to do their bit, and we were also replacing all of the wood blocking and everything all along the bottom edge before we could put our flashing on,” Tenoever recalls. “It took a lot of coordination between the two trades, but it all worked out.”

The Low-Slope Roof Systems

Owens Roofing served as the general contractor on the project and installed the low-slope roof systems. The company was established in 1986 in Raleigh, and focuses on commercial and institutional buildings, almost exclusively re-roofing. Much of its work is on historic buildings, so Owens was confident he could execute the project and complete it on schedule.

A scaffolding system offered secure roof access, but material had to be loaded and removed from one access point, so logistics had to be carefully mapped out.

A scaffolding system offered secure roof access, but material had to be loaded and removed from one access point, so logistics had to be carefully mapped out. Photos: SkySite Images

Crews from Owens Roofing installed 18,900 square feet of modified bitumen roofing from Soprema over concrete decks, including the areas between the pyramids. Tapered polyiso and half-inch DEXcell cover board from National Gypsum were installed using Duotack adhesive, followed by the two plies of modified bitumen membrane.

A liquid waterproofing system from Sika was specified for the large planter areas. Crews from Owens Roofing removed the existing plants, media and drainage system from four 42-foot-by-42-foot fixed planters with skylights. After the substrate had been cleaned and primed, the Sika RoofPro system was installed.

“Once it’s cleaned and primed, it’s pretty simple,” says Owens. “The product is one part, and you don’t even have to mix it. We applied it with rollers on this project. You embed fabric sheets in the system and then topcoat it. It was a cold-weather job, but fortunately we caught a break last winter in that it wasn’t as cold as usual, and we didn’t miss as much time as we might have.”

The 30,000-square-foot promenade section was originally covered by white granite pavers native to North Carolina. The old pavers were removed and replaced over a new roof system, which was comprised of modified bitumen sheets beneath the liquid-applied waterproofing system. “The concrete deck was primed and a modified bitumen base ply heat welded to the deck,” Owens explains. “This surface was primed in preparation for the Roof Pro system, which was then installed.”

Innovative Roof Services of Raleigh was called in to conduct a high-voltage electrical testing to ensure there were no voids in the system before the pavers were re-installed. The pavers had originally been set in a bed of mortar, and they had to be removed and cleaned, which revealed a problem. “When we took the pavers up, we found out that they ranged between 1-1/8 and 1-3/4 inches thick,” Owens notes. “That wasn’t a problem when they were set in a bed of mortar, but over extruded polystyrene, they would have been all up and down. We put in a change order and had the pavers set in a bed of sand on top of one layer polystyrene.” The sand was adjusted by hand to ensure the pavers were level. New pavers were added to replace those broken over the years.

On the roof’s concrete eyebrows, damaged areas of concrete were repaired, joints were sealed, and a cold-applied waterproofing system from Sika Sarnafil was used to cover 8,800 square feet of concrete.

Numerous Challenges

Important considerations on the project included safety and logistics, as well as the tight schedule. Safety was paramount, and a third-party safety monitor was on the site to ensure the safety plan was designed and executed properly. During the time between when the original skylights were removed and when their replacements installed, the voids in the roof deck needed to be cordoned off and covered according to OSHA regulations. Personal fall arrest systems were used on the pyramids and outside of the safety perimeter, which was marked with flags. “With the promenade, you had a wide concrete eyebrow, so it made it easier to set up the safety lines and keep everyone safely away from the edge,” Owens notes.

This aerial photo taken before the restoration project shows the copper roofs with their green patina. Photos: SkySite Images

“Safety is a key concern as on all jobs, but this one in particular was highly visible out the windows of the nearby Department of Labor,” Owens continues. “We were paid a courtesy visit and agreed with them that an on-site safety meeting conducted by their personnel might be useful. The owner allowed us use of one of their auditoriums and we had a very productive half-day meeting for all trades. Every week we had a meeting with a state construction monitor.”

A scaffolding system was set up that offered secure roof access, but there was only one point for loading and unloading material, so logistics at the site were a concern. “We had to use wheelbarrows and roof carts to transport materials back and forth to the scaffolding tower,” Tenoever notes. “Between the removal of the original roof and the installation of the multiple layers of the new roof system, over 150,000 square feet of roofing materials were moved by hand over an average distance of approximately 200 feet.”

Loading and unloading added another wrinkle to the complicated schedule. “The schedule was based on when the legislature was scheduled to come back to town—not how long the job was supposed to take,” Owens says. “We were all concerned with the ambitious time frame and $1,000 a day liquidated damages included with this job.”

Willers cited excellent communication as one of the keys to completing the project on time. “Fortunately, the project managers for the general contractor and other trades were highly organized individuals,” Willers says. “Regular site meetings were detailed and thorough. Although setbacks did occur, communication kept the ball rolling.”

The roof system on the building’s iconic copper clad pyramids was removed and carefully recreated, matching the original design while adding a vented cavity and increasing the thermal insulation. Photos: SkySite Images

A Unique Experience

Copper removed from the existing roof was salvaged and recycled, notes Willers, with the exception of a few pieces that

were cut into the shape of the state of North Carolina to serve as mementos of the unique project. “We’re very proud of the design and the outcome—and the assistance we got from all of the contractors involved,” Willers says. “We had some pretty heavy rains after the project was completed, including some high winds, and there were no leaks.”

Tenoever also looks back on the project with pride. “A one-of-a-kind roof system was custom built and delivered on schedule and with the owner and designer’s praises,” he says. “Taking something so amazing and restoring it to the beauty it originally had—we all get a kick out of that.”

TEAM

Design and Engineering Services: Raymond Engineering, Raleigh, North Carolina, RaymondLLC.com
General Contractor: Owens Roofing Inc., Raleigh, North Carolina
Metal Roofing Contractor: The Century Slate Company, Durham, North Carolina, CenturySlate.com
Leak Testing: Innovative Roof Services, LLC, Raleigh, North Carolina, IRS-LLC.net

MATERIALS

Metal Roof System
Copper: 20-ounce copper sheet metal
Vented Nail Base: Hunter Cool-Vent, Hunter Panels, HunterPanels.com
Underlayment: Carlisle WIP 300HT, Carlisle, Carlislewipproducts.com
Skylights: Wasco Skylights, Wascoskylights.com

Modified Bitumen Membrane Roof System

Membrane: Sopralene Flam 180 and Sopralene Flam 180 FR GR, Soprema, Soprema.us
Adhesive: Duotack, Soprema
Insulation: Sopra-Iso, Soprema
Cover Board: DEXcell, National Gypsum, NationalGypsum.com

Waterproofing System

Liquid Applied Membrane: RoofPro 641, Sika Corp., USA.Sika.com
Reinforcing Fabric: Reemat, Sika Corp.
Primer: Sikalastic EP Primer/Sealer
Extruded Polystyrene Insulation: Foamular 604, Owens Corning, OwensCorning.com

Contractor Restores the Roof on the Museum Beneath St. Louis’ Historic Gateway Arch

Western Specialty Contractors restored the roof of the Museum of Westward Expansion located beneath the Gateway Arch in St. Louis. This photo shows the protection board being installed prior to adding the leak detection system.

Western Specialty Contractors restored the roof of the Museum of Westward Expansion located beneath the Gateway Arch in St. Louis. This shows the protection board installed prior to adding the leak detection system.

The St. Louis branch of Western Specialty Contractors recently completed a project to restore and waterproof the roof of the Museum of Westward Expansion located beneath the iconic Gateway Arch on the St. Louis Riverfront. The work is part of a multi-phase project, spearheaded by nonprofit organization CityArchRiver Foundation, to expand and renovate the underground museum, plus renovate the grounds surrounding the Arch. The Jefferson National Expansion Memorial, which includes the Gateway Arch, Museum of Westward Expansion and the surrounding park, is maintained by the National Park Service.

Opened to the public in 1976, the Museum of Westward Expansion has undergone very few changes since its grand opening. The size of a football field, the museum features rare Native American Indian artifacts and materials documenting the days of Lewis and Clark and the 19th century pioneers who shaped the history of the American West.

Work on the 100,000-square-foot museum roof project began with removing sod and sandy soil covering the top of the roof and 10-28 inches of Elastizell engineered fill using a bulldozer. Next, the existing waterproof membrane was removed from the structural concrete deck.

After two layers of modified bitumen sheet waterproofing were installed, crews apply a coat of adhesive to adhere the asphaltic protection board.

After two layers of modified bitumen sheet waterproofing were installed, crews apply a coat of adhesive to adhere the asphaltic protection board.

Once the deck was exposed, Western crews went to work identifying and repairing leaks in the existing museum lid that had been present for many years, as the existing waterproofing had exceeded its lifespan. Several methods were used to evaluate the condition of the structural concrete deck, which included a chain-drag sounding along with visually identifying delamination and cracks.

Western crews then installed a two-ply Laurenco modified bitumen sheet waterproofing system covered with WR Meadows PC2 protection board. An electronic leak detection system followed by a permanent leak detection grid system were installed over the protection board. Crews then installed a layer of 1-1/2 inch, 60-psi Dow extruded polystyrene with an additional layer of the protection board and a J-Drain 780 drainage mat.

The next phase of the project involved waterproofing the 42,000-square-foot horizontal lid and the 37,000-square-foot vertical walls of the museum addition. Western’s scope of work in this area included installing a two-ply modified bitumen sheet waterproofing and protection board, as well as an electronic leak detection system, along with two layers of extruded polystyrene. A layer of extruded polystyrene was also installed on the vertical walls, followed by the drainage mat on both the horizontal and vertical walls.

During portions of the project Western crews were working over occupied space, as the museum was largely operational during construction.

During portions of the project Western crews were working over occupied space, as the museum was largely operational during construction.

Additional waterproofing of the north and south museum entrances encompassed approximately 13,800 square feet, which included approximately 5,000 square feet of deck around each leg of the Arch.

The museum was largely operational during construction, and for much of the project Western crews were working over occupied space. The company sequenced the removal of existing roofing material so that they could remove, clean and install new roofing material daily to keep the museum dry during construction.

Testing was a daily requirement during the waterproofing installation. Western was required to complete a pull test for every 500 square feet and take moisture readings for every 100 square feet. Daily observation reports had to be completed during the waterproofing application, with all testing results and location tests documented along with the weather conditions. Additionally, Western crews took 50 photos daily to document the testing and work area.

Construction on the Arch grounds began in August 2013, while renovations to the museum and visitor center began in April 2015. The multi-phase project is still underway, and the improved underground Museum of Westward Expansion is expected to be finished by summer 2018.

TEAM

Roofing Contractor: Western Specialty Contractors, St. Louis, Westernspecialtycontractors.com

MATERIALS

Waterproofing System: Laurenco Waterproofing, Laurencowaterproofing.com
Protection Board: WR Meadows, WRmeadows.com
Extruded Polystyrene: Dow, Dow.com
Drainage Mat: J-Drain, J-Drain.com