Skip to main content

Scope

Marriage joints between modular home modules at all exterior boundary conditions fully sealed with gasket and foam
Marriage joints between modular home modules at all exterior boundary conditions fully sealed with gasket and foam

Air-seal the marriage joints between sections of a modular or manufactured home with gasket material or spray foam.

  • Install a gasket along the entire seam of the exterior boundary where modules are attached together.
  • When modules are in place, seal the edge of the gasket to the module.

See the Compliance Tab for links to related codes and standards and voluntary federal energy-efficiency program requirements.

Description

In modular or manufactured homes that are delivered to the site in two (or three) sections, the joint where the sections of the structure are joined together is called a marriage joint. (It is sometimes also referred to as a marriage line or mating joint.) Marriage joints can be significant sources of air leakage. They should be properly gasketed and sealed to avoid leakage and maintain indoor air quality. Air leakage leads to heat loss in the winter and cooling losses in the summer.

Double-section modular homes are transported to the site as two separate sections. The marriage joints, beam joists, and walls are aligned and connected at the site. The roof, walls, and floor along the marriage line must be properly aligned, sealed, and supported.

Modular home manufacturers offer two options for delivery of manufactured homes to the home site: turn-key or rough set. With the “turn-key” option the manufacturer constructs the foundation, delivers the home, sets the home on the foundation, seals the marriage joints, and performs all finishing work. With the “rough-set” option, the home is delivered to the site by the manufacturer and placed on a foundation built by a third party (Steven Winter Associates 2001). The third-party contractor is responsible for ensuring the marriage joints are properly gasketed and air sealed.

 

A typical two-section modular home installation on a pier and ground anchor system. The middle line between the modules is the marriage joint.
Figure 1. A typical two-section modular home installation on a pier and ground anchor system. The middle line between the modules is the marriage joint (Source: Courtesy of FEMA). 

 

How to Air Seal the Modular Home Marriage Joint 

  1. Install a gasket along the entire seam of the marriage joint. If the manufacturer has already installed the gasket, ensure that each step below was performed.
    1. Install the gasket to the ceiling, walls, and floor prior to joining the sections together.
    2. Fold the gasket in half and fasten along the mating surface with nails or staples. Fasten at intervals of 6 inches on center (NFPA 2013).
Gasket installed along entire seam of the modular home marriage joint
Gasket installed along entire seam of the modular home marriage joint
Gasket installed along entire seam of the modular home marriage joint
Source
Author(s)
National Fire Protection Association
Organization(s)
NFPA
Description

Standard for installing manufactured homes, including specifications and procedures, for installation of utility connections of a manufactured home.

Figure 2. A gasket is installed along entire seam of the modular home marriage joint (Source: Courtesy of NFPA). 

    2. After the sections have been put in place and attached, air seal the entire perimeter of the gasket to the section walls, floor, and ceiling. Use an appropriate sealant such as caulk, foam, or silicon. 

Ensuring Success

Marriage joints between portions of modular homes should be visually checked to ensure that a gasket is installed along the entire seam of the modules and the outside portion of the gasket is fully air sealed.  An experienced technician can also check for air leaks with a smoke pencil or by feeling with the back of the hand. Air barrier effectiveness is measured at the whole-house level by blower door testing, which may help indicate whether marriage joints have been successfully sealed. To ensure indoor air quality and code compliance, air sealing strategies must be accompanied by whole-house ventilation systems and local mechanical exhaust.

Region

No climate specific information applies.

Training

Right and Wrong Images

No gasket installed at marriage wall connection prior to assembly
No gasket installed at marriage wall connection prior to assembly
No gasket installed at marriage wall connection prior to assembly
Source
Courtesy Of
EPA
Right - Gasket installed at marriage wall connection prior to assembling modules
Right - Gasket installed at marriage wall connection prior to assembling modules
Right - Gasket installed at marriage wall connection prior to assembling modules
Source
Author(s)
U.S. Environmental Protection Agency,
ENERGY STAR
Organization(s)
EPA
Description

Guide describing details that serve as a visual reference for each of the line items in the Thermal Enclosure System Rater Checklist.

No gasket installed at marriage wall connection prior to assembly
No gasket installed at marriage wall connection prior to assembly
No gasket installed at marriage wall connection prior to assembly
Source
Courtesy Of
EPA
Right – Wood-to-sheathing joints are caulked so the sheathing can provide an air barrier for the home.
Right – Wood-to-sheathing joints are caulked so the sheathing can provide an air barrier for the home.
Right – Wood-to-sheathing joints are caulked so the sheathing can provide an air barrier for the home.
Source
Right – All wood-to-wood joints are sealed with caulk.
Right – All wood-to-wood joints are sealed with caulk.
Right – All wood-to-wood joints are sealed with caulk.
Source
Right – A foam fabric gasket is installed in the header of this wall.
Right – A foam fabric gasket is installed in the header of this wall.
Right – A foam fabric gasket is installed in the header of this wall.
Source
Right – All wood-to-wood joints are sealed with sprayer-applied sealant.
Right – All wood-to-wood joints are sealed with sprayer-applied sealant.
Right – All wood-to-wood joints are sealed with sprayer-applied sealant.
Source

More Info

References and Resources

Publication Date
·
Author(s)
U.S. Environmental Protection Agency,
ENERGY STAR
·
Organization(s)
EPA
Description
Guide describing details that serve as a visual reference for each of the line items in the Thermal Enclosure System Rater Checklist.
Publication Date
·
Author(s)
National Fire Protection Association
·
Organization(s)
NFPA
Description
Standard for installing manufactured homes, including specifications and procedures, for installation of utility connections of a manufactured home.
Publication Date
·
Author(s)
U.S. Department of Energy
·
Organization(s)
DOE
Description
Website listing implementation timelines and links to various versions of the DOE Zero Energy Ready Home national program requirements.
Publication Date
·
Author(s)
U.S. Environmental Protection Agency
·
Organization(s)
EPA
Description
Website providing the technical specifications and related documents for home builders, subcontractors, architects, and other housing professionals interested in certifying a home to the EPA's Indoor airPLUS program requirements.
Publication Date
·
Author(s)
ENERGY STAR
·
Organization(s)
ENERGY STAR
Description
Website showing compliance timelines for various versions of the ENERGY STAR Single-Family New Home program requirements with links to national program requirements documents and checklists.

*For non-dated media, such as websites, the date listed is the date accessed.

Contributors to this Guide

The following authors and organizations contributed to the content in this Guide.

Sales

Building Science-to-Sales Translator

Tight Air Sealed Home = Comprehensive Draft Protection

Image(s)

Technical Description

Poorly air-sealed homes are less comfortable and cost more to maintain because they provide a pathway for drafts, cold spots, moisture, and insects into the home. Comprehensive draft protection includes a continuous air barrier around the whole house along with caulking and sealing in all holes and cracks. This includes around wiring, plumbing, ducts, and flues; where wall framing meets flooring; around windows; where drywall meets top plates and sill plates; where rim joists meet foundation walls and subfloors; etc. Spray foam insulation can be used at rim joists, floors above unconditioned space, and in attics to insulate and air seal at the same time.

Comprehensive Draft Protection
Sales Message

Comprehensive draft protection minimizes air flow that can undermine a complete high-performance insulation system. What this means for you is less wasted energy along with enhanced comfort, health, quiet, and durability. Wouldn’t you agree it would be a shame to only get a partial return on your investment in advanced insulation?

Last Updated

Questions? Comments? Contact our webmaster.

Disclaimer

This content is a work created with funding provided by the United States Department of Energy under Contract no DE-AC05-076RL01830 for the operation of Pacific Northwest National Laboratory. The information and guidance provided by Pacific Northwest National Laboratory (PNNL) in the content are intended solely for educational purposes only and do not constitute formal training or certification. It is provided with the explicit understanding that neither the United States Government nor the United States Department of Energy, nor the Contractor, nor any or their employees, nor any jurisdiction or organization that has cooperated in the development of these materials, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness or any information, apparatus, product, software, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Viewers assumes full responsibility for all actions that they may take from information provided in this content including ensuring the safety, code compliance, and proper functionality of any products they choose to install. Installation and use of such products should be performed in accordance with local regulations and manufacturer instructions.