Off-Site Modular Construction Considerations for Specification of Adhesives and Sealants

Posted on 12/10/2020 3:36:07 PM By Paul Bertram

According to the Modular Institute 2019 Permanent Constructions report, interest includes:

  • Quicker Occupancy – Streamlined Modular Construction process may be 30 to 50% faster than conventional on-site construction
  • Provides more efficient use of skilled labor
  • Predictability – Due shortened schedules, up-front material purchases, reliable labor and hedge against market uncertainty.

I would also add that Off-Site/Modular Constructions may reduce risk and liability because of better construction processes.

In my observations from my Construction Specifications experience, currently there is no one way to specify material components in Off-Site/Modular Constructions. In asking specifiers how Adhesives and Sealants are specified in an Off-Site/Modular project many suggested there is no difference. They use Master-Format sections with manufacturers CSI 3-Part specifications. An alternative was the use of “Sheet Specifications.” According to CSI’s Project Delivery Practice Guide, there are no specific guidelines for “Sheet” specifications other than a concise such as found in an “Outline” specifications.

See example of “Sheet” specification below…


  • Provide products that comply with the Contract Documents that are undamaged and new at the time of installation.
  • Provide products complete with accessories, trim, finish, fasteners, and other items needed for a complete installation and indicated use and effect.
  • The Architect will select all colors based on samples provided by the Contractor.
  • When matching existing is required, provide samples that allow fair evaluation of the Contractor’s proposed match.
  • Do not make substitutions for specified items without the Architect’s written approval.
  • Submit to the Architect shop drawings, samples, and other information requested. Verify Architect’s approval of submittals before ordering any products.


  • Deliver, store, and handle products using means and methods that will prevent damage, deterioration, and loss, including theft.Comply with manufacturer’s written instructions.
  • Delivery and Handling:
    • Deliver products to Project site in an undamaged condition in manufacturer’s original sealed container or other packaging system, complete with labels and instructions for handling, storing, unpacking, protecting, and installing.
    • Schedule delivery to minimize long-term storage at Project site and to prevent overcrowding of construction spaces.
    • Inspect products on delivery to ensure compliance with the Contract Documents and to ensure that products are undamaged and properly protected.
  • Storage:
    • Provide a secure location and enclosure at Project site for storage of materials and equipment.Coordinate location with Owner.
    • Comply with product manufacturer’s written instructions for temperature, humidity, ventilation, and weather-protection requirements for storage Store materials in a manner that will not endanger Project structure.
    • Store products that are subject to damage by the elements under cover in a weather-tight enclosure above ground, with ventilation adequate to prevent condensation.


  • Prepare products for installation according to manufacturer instructions and referenced standards.
  • Test substrates and remediate objectionable conditions prior to installation.


  • Install products according to manufacturer’s instructions and specific recommendations addressing project conditions.


  • The Owner reserves the right to require field-testing of installed products.The Contractor shall assist testing agencies engaged by the Owner in matters of scheduling, site access, and collecting and storing samples taken for testing purposes.

                                   (click on image to enlarge)

Slenderwall Prefabricated Wall Systems provides this Guide specification, as an example


This document provides a basis for specifying in-plant fabrication, including product design, not shown in contractdocuments, and the field erection of the SLENDERWALL® Prefabricated Wall Panel/System. It does not include structuralprecast concrete, coatings, or sealing the joints between units.



The Fabricator’s drawings show the location and details of applied and embedded items. The drawings illustrate thedetails of structure corners and interfacing with other materials. The drawings identify the requirements for design anddesign loads and indicate load support points and space allowed for connections.

The Engineer of Record needs to be aware of the magnitude and direction of all anticipated loads to be transferred to thebuilding structural framing and their point of application. It is especially critical that the Engineer of Record provide stiffenersand bracing that are required to transfer the loads imposed by SLENDERWALL® to the structural frame of the building.


The SLENDERWALL® fabricator may be responsible to supply SLENDERWALL® support items to be placed on or inthe structure in order to receive the SLENDERWALL® units, depending on the type of structure. This is dependentupon local codes, practice, and building superstructure design.

The National Institutes of Building Sciences,  Whole Building Design Guide is a great resource for specifying sealants and Adhesives. In a recent MOU between ASC and NIBS, ASC has committed to update the section on Adhesives and Sealants.



ASC has created a great
reference web portal for manufacturers, design professionals, specifiers and installing contractors.

Currently there is no specific “modular building code” or exceptions for a building constructed utilizing the modular construction process. It is simply a different and more efficient process to assemble the materials and components of a building. Modular construction can be utilized for residential, commercial, or industrial applications. 

In response to industry confusion in delivering a complaint an Off-Site/Modular project, ICC IS-OSMC Off-Site and Modular Construction Standards Committee was formed and are nearing completion of the proposed Standard.

Keys areas of the proposed  ICC OFF-SITE AND MODULAR CONSTRUCTION STANDARDS COMMITTEE (IS-OSMC), that are potentially relative to adhesives and sealants, include:

A Key Plan for off-site components shall be provided, all off-site components delivered to the site shall be identified with unique numbers.

Documents shall be reviewed by any third party or special inspectors against submitted permit drawings.

Inspections generally include in-plant inspections and on-site inspections. Documentation identifying individuals or parties responsible for the inspection of installations and components shall be identified and provided to AHJ prior to the commencement of an inspection process.

Inspections generally shall include in-plant inspections and on-site inspections.


Designs, plans, and specifications, including written, graphic, and pictorial documents, prepared or assembled for describing the design, location and physical characteristics of the off-site construction the elements of a modular building necessary to show compliance with the applicable building codes.

Remote Virtual Inspections. The AHJ shall have the option to conduct remote virtual inspections

QA/QC personnel. Each manufacturing plant shall identify a responsible party that shall implement the QA/QC processes within the facility.

These are just a few of the considerations being included in the proposed ICC OFF-SITE AND MODULAR CONSTRUCTION STANDARD.