The Use of MS POLYMER™-Based Sealants and Adhesives in Modular Building
Luc Peeters is the R&D Manager, Performance Polymer Solutions Vehicle | MS Polymer Division at Kaneka.
One of the major advantages of modular building is construction in a factory under controlled conditions. In many cases, an assembly line system is implemented that moves the modules through the factory depending on the construction stage. Hence, the modules are subjected to more movement and vibrations compared to traditional construction methods. In the final stage, the modules are transported on a truck to the building site, again subjecting the modules to vibrations and shocks. It can result in cracking of joints and adhesives leading to cracking or falling of tiles or other materials. As a result, a lot of assembly and finish work has to be done on the building site.
MS POLYMERTM, a silane modified polymer (SMP), was developed in Japan as base resins for sealants and joint fillers to protect buildings against earthquakes—simply put: the SMP provides a high elongation and elastic recovery to cope with vibrations and movement of the building. Since the rollout of that initial product, additional adhesives were specifically developed for tiling—for instance, in railway stations where cementitious adhesives will crack over time and tiles can fall off the walls.
Keeping these properties in mind, the SMP-based adhesives and sealants are ideal products for the construction of modular buildings and provide solutions for both exterior and interior adhering and sealing.
Fig. 1 Cut-through of the outer wall
Fig. 2 Cut-through of a flat roof
Exterior Applications of SMPs
Exterior walls can vary widely, but many consist of different layers starting with a wooden or fiber cement panel on which insulation panels are adhered. These connections can be made stronger by using SMP panel bonding adhesive. The wall can then be made even more air- and water-tight by sealing it off with a panel adhered with a tackified SMP foil adhesive. The final finishing of the wall can be done with stone strips, as conventional bricks are too heavy, or wooden or composite panels by using a SMP stone strip adhesive or panel bonding adhesive or a high tack adhesive. To prevent any cracking of the outer wall, an expansion joint with a low modulus sealant can be applied.
When we then take a look at the roof, which are often flat in modular buildings, again often find wooden panels with insulation panels adhered on top with an SMP-based insulation or high tack adhesive. For covering large areas there are already sprayable adhesives available. The roof can then be finished with an EPDM, TPO, or bitumen membrane which can all be adhered with SMP-based adhesives. The solid membrane can also be substituted with liquid applied membrane which can be applied with a roller or squeegee.
Any pipes or gutters can still be sealed with a detailed roof sealer.
Interior Applications of SMPs
Interiors can vary widely, but there are many ways the SMPs can help secure and seal various components. Floors, for example, are often based on panels with a wood laminate, parquet, or LVT floor adhered. For all these types of flooring, specific SMP based adhesives are available.
To prevent cracking and distribute vibrations and movements, elastic joint sealants with excellent recovery are required for sealing the skirt board, but also for sealing the joints between the plaster, wood-, or cement fiber-based panels.
For all the assembly of racks, sinks, etc., general purpose adhesives and sanitary sealants are available.
For wet areas such as bathrooms and showers, specially-designed SMP products need to be used. One option is a watertight coating based on newly-developed low viscosity SMP grades which can be applied under tiles. Kaneka has also developed a new reactive tile adhesive that passes EN-12004-RT2, which up to now was only possible with epoxy adhesives. To enable even more time saving, a 2-in-1 coating was developed which combines the watertight coating and the tile adhesive in one product.
Testing the Strength of SMPs
During assembly, the modules are moved through the factory, and once construction is complete, the modular building is transported by truck to the building site. During this movement and transportation process, the building is exposed to vibrations and shocks, which can result in issues such as cracked or detached tiles.
To demonstrate that elastic SMP-based sealants and adhesives can effectively prevent tile cracking and detachment, a truck transport simulation was conducted in accordance with ASTM D4169-23. In this test, a test piece with tiled panels was placed on a vibration table and subjected to a controlled vibration cycle.
The cycle included:
- 15 minutes of truck vibration at low level (random, 1–200 Hz, control: 0.40 Grms)
- 15 minutes at medium level (random, 1–200 Hz, control: 0.54 Grms)
- 5 minutes at high level (random, 1–200 Hz, control: 0.70 Grms)
This test cycle simulates the vibrations experienced over a 400 km truck journey in real-world conditions.
The test piece consisted of two OSB panels and two fiber cement boards. Four different adhesives were applied, three cementitious and one SMP-based. On each type of board, eight white ceramic tiles (20 cm x 20 cm) were adhered using the different adhesives without applying any primer (see Fig. 4).
The results shown in table 1 show that the SMP-based adhesive offers the best performance for modular building applications. It maintains strong adhesion even on challenging substrates such as OSB panels, without the need for a primer, and withstands long-distance transportation without compromising the integrity of the tile installation.
Table 1: Test results of truck transport simulation (ASTM D4169-23)
Fig. 3 Cut-through of a shower wall
Fig. 4 Picture of the assembled test piece
Fig. 5 Test piece during the vibration test
Conclusion
After taking a closer look at a modular building process, it becomes clear that both the interior and exterior can be completely constructed and assembled by using MS POLYMERTM-based sealants and adhesives. These products combine flexibility and elastic recovery with excellent adhesion to different substrates and have already shown their usefulness in traditional construction. Now it’s time for them to be put to use in the modular construction industry.
More from Modular Advantage
Mind the Gap: The Interface Between Onsite and Offsite Construction
Every design for manufacture and assembly (DfMA) project — modular, mass timber, or panelized — is really two projects joined at a seam. One is built in a controlled factory to millimeter tolerances; the other in the field, in weather, to the looser tolerances of poured concrete and human hands. Between them sits an interface: where the factory’s precision meets the site’s reality.
Rules, Rails & Repeatability: Applying DfMA to Modular Healthcare
DfMA offers several advantages for healthcare projects, with faster delivery among the most valuable. Schedule matters when building new facilities, expanding campuses, renovating existing space or bringing care closer to communities that need it.
Precision and Possibility: Demands of DfMA and What Modular Mass Timber Makes Possible
Mass timber does not automatically create an efficient modular building. Its precision makes early coordination more important: fabricated components will accurately reproduce both the team’s solutions and its mistakes. The material’s advantages are realized only when supported by an equally precise design and delivery process.
Catch It in the Factory, Not in the Field: Smarter Testing for Modular Builds
Integrating watertightness and airtightness testing into factory workflows transforms quality assurance from a reactive process into a proactive commissioning strategy. It ensures that every module shipped is field ready and resilient for transportation while also supporting the ability of the modular construction industry to make buildings better.
Modular Construction Contracts: Key Considerations for Successful Canadian Projects
Starting a modular project with a well-developed contract protects both the owner and the contractor. It will help keep the project on track and on budget, and it will improve quality from the factory floor to final installation on-site.
Modular by Design: Turning Architecture into a Manufacturing System
Modular construction is often presented as a faster way to build. Speed, however, is only one part of its value. The larger opportunity is to create a coordinated design and production system that improves quality, reduces uncertainty, and allows a building to move efficiently from concept design through manufacturing, transportation, installation, and completion.
Repeatability Begins with Trust: What Alora at Dry Creek Reveals About Scaling Modular Housing
Alora at Dry Creek, a 329-unit, multifamily community comprising five four-story buildings in Centennial, Colorado, demonstrates how repeatable design, standardized manufacturing and early collaboration can work together to create a model that is not only faster to deliver, but easier to replicate across future projects.
T.R. Arnold: The Art of Third-Party Inspections
T.R. Arnold (TRA), a third-party inspection company in Elkhart, Indiana, contracts with modular manufacturers across the US. Manufacturers register with each state to which they intend to send their modules and may be required to hire a third-party inspection company.
Creating an ‘Ecosystem for Innovation:’ 50+ Years of Modular Construction Oversight in Virginia
Virginia’s modular building program began in 1973, with the implementation of the Virginia Industrialized Building Unit and Mobile Home Safety Regulations. Now it’s leading the country in modular code adoption.
Understanding Thermal Barriers Compliance Methods & Emerging NFPA-275 Foam Plastic Technologies
New fire barrier technologies are improving total costs and margins in major areas of construction, such as commercial, government, union and prevailing wage projects. These benefits translate into other large fringe areas, such as agriculture, commercial cold storage facilities, grow houses, outbuildings, military and aviation hangars.