MJS™: Durable Waterstop System

The MJS™ System is a long-lasting solution for dams, locks and other structures. The system holds up to water and joint movement without damaging the system itself.

MJS™: Durable Waterstop System

The MJS™ System is a long-lasting solution for dams, locks and other structures. The system holds up to water and joint movement without damaging the system itself.

MJS™ Monolith Joint Seal System

STRUCTURAL TECHNOLOGIES’ MJS™ is a proprietary replacement waterstop monolith joint seal system that controls leakage of water through existing joints, particularly in dams, locks, large retaining walls and other structures.

The system is installed in a drilled hole and uniformly pressurized to offset hydrostatic pressure. 

The MJS™ System is a long-lasting solution that holds up to water and joint movement without damaging the system itself.

MJS SystemsInstalled in a drilled hole
  • Ensures continuity throughout length of joint.
  • System won’t track into opened joint – preventing damage to the dam seal
  • May be removed or replaced
Maintains uniform internal pressure
  • Offsets hydrostatic pressure from the water source regardless of joint movement
  • Accomodates pressure heads to 150 psi and depths over 300 feet
  • Adapts to variation in weather from -50°F to 120° F

Waterstopn Systems

Overall System Advantages
  • Maintains water control when the joint opens and closes
  • Eliminates need for divers
  • Eliminates need for chemicals to contaminate water supply
  • Easily maintained and serviced
  • Restores original water control features designed into the structure
  • Easy to inspect via remote cameras during and after installation


Specialty Products develop by Structural Technologies

Engineered Solutions for Moisture Control

Moiture Control

STRUCTURAL TECHNOLOGIES’ Moisture Control Team provides solution building services for difficult-to-solve moisture problems. Our specialty is taking on problems where traditional products and design solutions have failed. Our experts integrate with engineers, owners and builders to assist with initial assessments through design and material selection

Our engineering support services for moisture control include:

  • Investigation and diagnostics for existing structures
  • Budget development
  • Material selection
  • Specialized products for unique applications
  • Specification development assistance
  • Means and methods development assistance
  • Design Assist Services
Solution-Building Areas of Concentration

Coatings Membranes

CoatingsSTRUCTURAL TECHNOLOGIES Solution Builders assist in the selection, design and detailing of various types of coatings and pre-formed membranes. While similar, coatings and pre-formed membranes may differ in overall use and performance

  • Coatings Coatings can be rigid or elastomeric and generally involve the application of material layer(s) to produce a film covering a surface. They can be designed to control water absorption, vapor transmission, and diffusion of aggressive liquids and gasses through the surface of a structure or member. Coatings can be filled with hardened aggregates and minerals to enhance wear and abrasion resistance. We assist in the selection, design and detailing of various types of coatings.
  • Pre-formed Membranes are sheet systems that may be bonded or loose-laid over the substrate. These membranes can be formulated to resist a vast variety of chemical exposures. Sheet systems require heat, tape, adhesives, or solvents to adhere overlapped seams. Sheet systems are factory controlled for thickness, dimensional stability, and internally reinforced for strength. Sheet membranes can have fabrics bonded to either or both sides to enhance mechanical penetration, adhesion, and assist in adhesion.. Typical pre-formed membranes include:
    • Thermosetting polymer sheets,
    • Vulcanized rubber sheets, and
    • Composite systems

Grouting / Injection

Chemical Injection

STRUCTURAL TECHNOLOGIES Solution Builders assist engineers, owners, and property management agents in product selection, design, detailing and “means and methods” specifications of a wide variety of grouting and crack injection solutions for a wide range of applications.

Chemical grouts are injected under pressure into or around structural elements for either or both moisture control and strengthening. Moisture control pressure grouting is injected into concrete defects within structural elements to make them monolithic. Monolithic concrete is considered water-tight.

Selection of chemical grout(s) is based on many structural, environmental, and chemical compatibility issues. The material properties of the grouts must be matched with the physical nature of concrete defects. Successful grouting practice involves a blend of “art” and ‘science”.

Commonly used and specified grouts include the following:

  • Epoxy (low viscosity)
  • Structural Urethane(s) (One part, two part, various viscosities)
  • Hydrophobic urethanes
  • Hydrophilic urethanes (foams and gels)
  • Polyacrylate (High solids to low solids)
  • Bentonite (Water or plasticizer, activated)
  • Polymeric Gel (High viscosity)
  • Acrylamides (Powder or liquid pre-polymers)
  • Sodium silicates
  • Micro-fine cements

Joint Seals

Waterstop systems

STRUCTURAL TECHNOLOGIES Solution Builders assist in the design and detailing of various types of joint seals .Joint seals are used in a variety of applications across industries and infrastructure types, creating moisture proof seals between the connections of various types of building materials. Joint seals typically deal with either pressure and or movement in performing their function of maintaining a watertight connection at a construction joints where different material come together (or where the design has incorporated the need to compensate for movement within the structure ) .

Joint seals consist of elastomeric glands, initially applied as sealants, preformed polymers, sheet membranes and expanded gaskets. Typical examples include:

  • Pressure-rated waterstop joints
  • Water control sealants- rout & seal
  • Load supporting glands, and
  • Traffic bearing expansion joints

Moisture Control Engineering Team Leader
Brent Anderson, P.E.
Moisture Control Engineering Leader

Brent Anderson, P.E.

Brent Anderson, P.E. has Bachelor and Master’s degrees in Civil Engineering and minors in Architecture and Mechanical engineering. He is a Member of American Concrete Institute, Society of Mining Engineers, International Concrete Repair Institute, Concrete Foundation Association, and American Society of Civil Engineers. He serves on ACI 332 Residential Concrete, and served on ACI 515 Protective Coatings for Concrete. Brent lectures throughout the United States at Higher Education Institutions.

Brent has over 34 years of experience in below-grade foundation and plaza deck waterproofing, chemical grouting with urethanes, micro-fine cements, bentonite's, acrylamides, acrylic’s and epoxies. He performs forensic foundation engineering for concrete problems (cracking,corrosion,deflection, and soil-settlement) and water leakage claims (roofs, cavity walls, building envelope, air/vapor barriers, floors). He has also provided expert witness services for waterproofing systems (products, installation, performance, design, and specification writing) and foundation problems.


STRUCTURAL TECHNOLOGIES' licensed engineering services are provided by Structural Technologies StrongPoint, LLC - A Structural Group Company, or through other licensed engineers.

Installation Support

Moisture Control SupportSTRUCTURAL TECHNOLOGIES provides construction phase support services to ensure that moisture control and waterproofing systems are installed properly and will carry out their intended functions. We coordinate with builders to provide project-specific oversight, quality assurance and quality control.

Turnkey Investigate – Design – Build Solutions

When paired with Structural Group's specialty contracting companies— we provide our clients with Turnkey Investigate-Design-Build services from forensic evaluation, product selection, setting of means and methods, and system installation with single source accountability. Together, we seamlessly integrate to deliver customized, cost-effective, and long-lasting solutions for moisture control problems.





STRUCTURAL TECHNOLOGIES — A Structural Group Company

With member companies dating back to 1902, Structural Group is firmly committed to its ongoing mission of making new and existing structures stronger and last longer. Through its member companies, Structural Group delivers turnkey solutions that integrate technology, engineering, and construction. Structural Group provides state-of-the-art products and engineering support services through STRUCTURAL TECHNOLOGIES and specialty contracting services through STRUCTURAL and PULLMAN

Learn more about Structural Group and its member companies.