How To Install Foam Board Insulation On Metal Roof?

insulation on metal roof

Do you know that switching to foam board insulation can save upto 20-50% of your heating and cooling costs?

Well, you have heard it right!

A foam board is a waterproof and durable material, which is added to the inside of your roof within the attic space and provides numerous benefits along with your house insulation.

It aids in saving energy, trapping heat inside the places where the temperature is cold, and also provides insulation against heat by controlling indoor temperature in summer. Apart from this, it is highly durable and prevents air leakage. When foam boards are used for the insulation on metal roof they reduce drafts and also save energy. Simultaneously, reducing bills with an insulating efficiency of more than 30%.

Foam board insulation effectiveness can also be proven from its thermal resistance, offering an R-value of about 3.6 to 8.0. It can be used in floors, ceilings, walls, and various other sectors of construction. Foam boards come in various sizes and qualities. The three different types of material from which foam boards are made are named as expanded polystyrene, extruded polystyrene, and polyisocyanurate. All three materials for insulating foams are easy to install and are cost-effective.

Understanding Foam Board Insulation

A foam board is a dense sheet that is laminated on either side. They are sized in 4 x 8 ft and 4 x 10 ft footboards and in terms of thickness 1 inch to 2 inches are widely used. The type of material that foam board is made of includes expanded polystyrene, extruded polystyrene, and polyisocyanurate.

EPS and XPS foams are made of polystyrene. EPS is made from non-cross-linked polymers or beads, while XPS is made from a molten material that is pressed afterward to form an insulating sheet. EPS has a higher R-value and higher density than XPS, ensuring better heat, moisture, fire resistance, and dimensional stability.

Polyisocyanurate is a closed-cell foam sheet It contains hydrochlorofluorocarbon-free gas, which is replaced by air and provides quality insulation, low conductivity, and a warmer interior.

Foam Board sheathing provides high-quality resistance from insects, pests, thermal, sound, moisture, etc. Moreover, it is easy to install and is cost-effective. The variety of benefits it provides makes it a top choice for property owners for insulation on metal roofs.

Tools And Materials Required For Insulation

Before you look for how to install foam board insulation, you may require a lot of tools such as an insulation cutter or saw, utility knife, a cloaking gun, sealing foil tape, drywall screws, staple guns, and various other tools including safety tools too for secure and error-free installation.

Safety tools and measures

When cutting foam boards, proper safety measures are essential to adopt. This ensures the foam board installation process is free from hurdles. Cutting into insulation foams like glass, plastic insulations, and other insulating materials may release particles that can be dangerous for the lungs and eyes and may cause irritation.

To prevent irritation and diseases, proper safety precautions must be taken with the help of tools.

  1. Insulation goggles to protect eyes.
  2. Mask and gloves to cover your mouth and hand
  3. Long-sleeved coat to protect the skin

Insulation Cutter

An insulation cutter can be used to cut through insulation foams so that it can be precisely fitted into the interior of the walls. Various brands offer insulation cutters that could be significant to cut straight through several insulation foams like :

  1. Polystyrene insulation foam
  2. Polyurethane insulation boards
  3. Facade insulation boards and more

Hot Knife Cutter

A hot knife cutter can also be a great tool to cut through the insulation foams. It is used to shape foam boards so they can be attached to the metal roof. A hot knife cutter is perfect for accurate cuts on a wide range of materials such as

  • Expanded Polypropylene
  • Expanded polystyrene
  • Extruded Polystyrene and more plastic foams.

Slap stapler

A slap stapler is a gun that can be used to staple foam sheets in place. It doesn’t have a trigger to staple the foam board, instead, you have to insert a staple pin by the whack of your arm. It is used to place the foam boards exactly in position and is an alternative for Staple guns.

Staple gun

A staple gun contains a trigger and directs a pin wherever you want to fix the foam board in place. It can be used to connect the foam board with the wall for better insulation and efficacious outcomes. Rather than needling with a hammer, you use a staple gun for the perfect placement of the foam sheets.

Sealing tape

Various sealing tapes such as foam tapes, plastic film tapes, and more can be used for proper placement and fixing corner positions of the foam boards, for the insulation work. This ensures accuracy and provides a cleaner finish to the board.


Adhesives are used to attach the foam board to the walls with ease. This makes it extremely easy for workers to set foam sheets, attaining durability and stability with precise positioning. It is very useful for attaching foam boards to walls, floors, and metal roofs.

Caulking Gun

A caulking gun is used to eject adhesives filling the space between the sheets. It can be used for accurate placement of foam sheets with clean finishes. Various foam boards are connected using adhesives, which are sprayed with the help of a caulking gun.

Gypsum board screws

Gypsum board screws are important for the installation of foam board to the metal roofs. The foam boards are attached directly to the drywall and roofs with the help of gypsum board screws. The screws help ensure durability and rigid placement.

Vapor control Layer

A vapor-resistant layer is added over the foam sheaths, within the wall structure to prevent the water vapors from entering into the building, hence enhancing the insulation from moisture. It is specifically a plastic layer that is added to the walls and the roofs of the structure. It not only prevents moisture but also avoids pests and insects that can cause harmful diseases.

Steps on how to install foam board insulation

Before the installation of the foam board to the inside of the metal roof, you need to make a proper estimation of all the tools and materials required for such a process. Moreover, labor costs must be evaluated, to ensure delay-free and timely process management.

The installation process may require an experienced person to carry out the insulation of metal roofs without errors. The foam board insulation involves the following steps

  • Safety first

To begin with the foam installation, workers need to equip the essential tools to enhance safety with the insulation sheaths. For that wear your gloves, goggles, and mask to begin without any problem, ensuring a secure environment.

  • Measure the project area

Measure the area of the roof, wall, or space where metal foams need to be installed. It is required to make measurements of length, dimensions, and the size of the foam board that might fit within the metal roofs.

Thoroughly analyze your roof and use an inch of tape to measure the length and width of the metal roof for proper insulation.

  • Mark and cut the foam

Once you have measured the metal roof you have to mark the foam board for cutting and proper placing. Use a marker to point to the place where it needs to cut down the insulation foam.

After that, take out the insulation saw, knife, or cutter for proper cutting of the foam without damage. Carefully cut the insulation sheet straight without errors, ensuring precision and immaculate outcome.

  • Install the foam insulation

Now, install the foam to the walls by using adhesives once they have been placed. Use a staple gun to connect the foam with the roof and the corners of the foam boards for accuracy and precise placement.

Use high-quality adhesives to attach the foam to the surface with the utilization of the slap stapler or staple gun. The work should be done by an expert for accurate results without errors.

  • Seal the Gaps in the Insulation

Now after they have been placed, seal the gaps together by spraying adhesives between the gaps of the two boards. This can be done using a caulking gun so that the adhesives can be sprayed with precision onto the spaces for accurate and sturdy placement.

After this process has been completed you need to add a vapor membrane layer so your roof is completely insulated from moisture and diseases.


Metal roof insulation requires the installation of insulation foams to the roofs. This process ensures resistance against heat, moisture, impact, sound, insects, pests, diseases, and more. It provides high-quality insulation with durability and long-lasting outcomes.

To proceed with the metal roof installation process it requires complete estimation of all the components, tools, and labor to install foam board insulation sheaths. So, if you’re looking to estimate the material and cost for the foam board insulation process, then our Insulation estimating services are here for you. We provide the most accurate and error-free estimates for your structure insulation project. Our expert teams provide