How To Seal A Mobile Home Marriage Line – Using Mating Gasket During Set Up.

using sill sealer as mating gasket

By placing a water-proof, airtight sealer between the sections of the mobile home prior to connecting the modules together. This ensures a barrier between the living area and the outside elements and the main home from the roof space.

Why is a Barrier Important?

With all homes, there is a difference in air temperature between the inside living area and the roof space. The temperature in the roof space on a summer’s day could be up to 50 degrees higher than the interior temperature. This is especially true with modern HVAC systems.

Moisture will form if the air from the two areas is allowed to mingle.

Properly installed mating gasket prevents air infiltration.

Long term this could cause unpleasant smells, mold, damage or dampness.

There is also the extra energy cost of allowing the free movement of cooled air between the sections.

What Is The Marriage Line?

The marriage line is the connection between sections of  a mobile home.

It includes the floor, the end walls and the join above the living area and support walls called the ridge beam. The marriage line area is used to join the sections together with bolts or screws during installation.

Mating gasket is best if it is securely attached at this time whilst the ridge beam is easily accessible.

What Is Mating Gasket used for?

To seal the opening between sections of the home.

Keep out moisture.

Separate the roof space from the living area.

Prevent insects and pests from gaining easy access.

Types of Material used to seal the gap.

Factory installed mating gasket on new homes.

Foam sill sealer from Home Depot or Lowes.


Expanding foam in cans.

Fiberglass insulation batts

Does Expanding  Construction Foam Do A Good Job?

No not really for a number of reasons.

It shrinks over time.

Cannot be used prior to the joining process.

Doesn’t get to the needed areas to seal properly.

Messy substance to use accurately.

How To Install Sill Sealer.

With the plastic shipping wrap removed and mobile home sections ready to mate together, sill sealer is folded double and attached to the home with a roofing nailer or slap stapler.

Start at one end stretching out the sealer before securely fastening to the home. Carefully work your way along the floor to the end wall leaving no gaps as corners are turned.

You will need a ladder to reach the ridge beam which is just above the living spaces.

Tools Needed To Install Mating Gasket On A Mobile Home.

Here is a list of tools which will be needed if you intend to do it yourself:

  1. 12 foot ladder
  2. Sharpe Knife
  3. Slap stapler or staple gun
  4. Compressor and hose (optional)
  5. Hammer
  6. Small prybar
  7. Safety glasses

Materials Needed To Install The Marriage Line Gasket.

Just a few cheap materials are needed:

  1. 3 rolls of sill sealer to use as the gasket
  2. Nails or staples

Pulling The Mobile Home Sections Together To Seal The Gap.

With the home stripped of all shipping materials which usually consists of polythene held in place by sticks and the gasket in place, the sections are now ready to be pulled together.

Ensure that the mating gasket that you have chosen is in contact with both sides of the floor, the end walls and the ridge beams above the living areas ceilings.

When installed correctly the gasket will not allow light to pass through the joint.

Make a thorough visual inspection of the mating line and fill in any gaps where needed.