Rigid Board Insulation Archive

Rigid Board Insulation

Pacific Insulation Supply saves you time and money when buying Rigid Board Insulation

 Rigid board insulation are board insulations that can be installed internally and externally to enhance thermal-insulation and sound-proof a room. There are varieties of rigid boards and options to install them throughout your construction. Here are some tips for finding the best types of rigid boards to install and where.

What is Rigid Board Insulation?

Rigid board and often known as the rigid panel insulations are the exposed exterior insulations that you commonly see on new buildings during construction.

They are generally made from two types of materials.

  • The first type is the foam plastics, polyurethane, polyisocyanurate, and polystyrene.
  • The second type is from fibrous materials (bulk materials of individual fibers) such as rock, slag wool, and the well-known fiberglass.

Rigid board insulations are known for their high R-value (the measurement of an insulating material’s resistance to conductive heat flow) per area thanks to its dense material. Unfortunately, they are UV sensitive and must be ensured full coverage. Lastly, they are usually more expensive than other types of insulations.


Kinds of Rigid Board Insulation

POLYISO (Polyisocyanurate, PIR) POLYISO is a closed-cell foam board made from polyisocyanurate. These boards are commonly found with two facers on each side made of organic and inorganic material. Oftentimes you will find the aluminum foil facing.

It is known for its common uses in commercial and residential buildings for roofs and low-slop insulations. They are also favored for its environmental awareness and responsible impact on the environment.

Their facers are known to be highly adhesive, with high strength and good absorption. The thermal performance is rated at R6 to 6.5 per inch, but unfortunately, they are not the best option for the colder (Chicago) weather.

The R-value: 6-6.5 per inch but not good during winters.

What we like

  • Stable temperature range
  • Low density and good adhesion to facers.
  • Good performance in fire tests.

What we don’t like

  • Sub-par for winter applications.

EPS (Expanded Polystyrene) EPS, also known as “beadboard,” has been available since the 1950s. It is a board made of expanded beads of polystyrene. When these beads are poured and expanded, the resulting air in the beads provides the insulation.

As a result, it is a closed-cell insulation with 98% trapped air and 2% plastic resulting from the expansion of the beads. The high level of air and space makes the material an efficient insulator.

EPS is known for its breathability and permeability. This can be good for insulation, but it is not the best option when you don’t want to trap moisture. In the wet stage, it can also drop in performance when it comes to overall insulation.

R-value: 4 per inch

What we like

  • EPS is great for its moldability. These are easy to cut and size appropriately to the awkwardly shaped areas where you want to install insulation.
  • There have been popularities with the contoured EPS which is beneficial for increased durability and increased impact resistance.
  • They are usually the cheaper selection of the rigid board family.

What we don’t like

  • Higher susceptibility to moisture damage due to its higher perm rating ranging in 60 to 75(without film facers).

XPS (Extruded Polystyrene)XPS is the commonly found rigid board insulation found in remodeling and new construction projects. This is also known as the common Styrofoam.

Due to its high rigidity and stiffness, it is durable and great for roofs, below slabs, and other applications.

R-value: 5 per inch

What we like

  • Energy-efficient
  • Higher R-value than the EPS

What we don’t like

  • They are restricted to a certain dimension and shape.
  • The depletion of the agents results in depreciation of insulation value over time.
  • Not environmentally friendly.

1 in. x 4 ft. x 8 ft. R-5 Scored Squared Edge Rigid Foam Board Insulation Sheathing
Known for its flexibility of changing the strength you need from 15 to 60 PSI and provided with moisture resistance, Owens Corning offers a great option for their R-5 rigid foam board. This is easy to cut and install with minimal tools required.

What we like

  • Minimal tools; a straight edge and razor blade will easily get the job done.
  • Paint-adhesive surface.
  • Durable and Versatile
  • Lightweight, durable, and heat resistant.

RMAX R-Matte Plus
3 3/4 in. x 4 ft. x 8 ft. R-5 Polyisocyanurate Rigid Foam Insulation BoardThis is often used for commercial, residential, and agriculture construction. Many users use this for the renovation of existing buildings.

It is cost-friendly, with great quality for a high R-value. The aluminum facer and reflective aluminum facer bonds in the Polysico board providing a high R-value per square inch. R-value of 5 is comparable to the 1-inch FOAMULAR mentioned above with the same R-value.

What we like

  • High R-value per inch.
  • Moisture and vapor resistance.
  • Lightweight and easy to use.
  • Energy Star Qualified.

Common Uses for Rigid Board Insulation

Rigid boards are often found on the exterior side of walls; this application’s purpose is to provide the thermal insulation in the building envelope. They are found on exterior foundation walls, and often between the foundation and the roof.

Additionally, rigid boards can be found on the exterior of studs in a framed wall or a mass wall assembly.

Products such as EPS are installed for ground contact. They can be installed against footings and back-filled foundation walls on the exterior.

For its rigid feature, rigid boards are also great for installing between sheathing and siding.

Note that these can be installed on interior walls also and are great for compact and limited spaces due to its high R-values and dense material. In the interior walls, prior to finishing, they can be seen in shapes like batts or as pre-cut pieces.

Brands of Rigid Board Insulation we carry


RMAX is an insulation and building company that was established in 1979. They are a company specialized in insulation solutions. They offer high-quality polyiso-based products in varieties of commercial, residential, and specialty products for heavy-duty projects and unique industrial applications.

They are known for their rigid board sheathings with foil on one side. They can vary in sizes from ½ inch to 4½ inches. They are known for their high R-values, efficiency in installation, cost, and design. Their purpose is energy efficiency and to keep their R-max values at the forefront.
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More info about XPS, EPS and Polyiso