There is an enormous selection of building materials available on the market today, and choosing the right materials can quickly become overwhelming. When it comes to insulation, you can choose from blankets to beads, boards and even blocks. From there, you have even more choices to make, such as the chemical makeup which can include various types of foam, fiberglass, and more.
Rmax simplifies the selection process in this article by breaking down a tried-and-true building component that they've been manufacturing for decades: rigid foam insulation.
What is Rigid Insulation?
Let’s start by answering the simple question: What is rigid insulation? Rigid insulation, like all insulation, is a building material used in construction that creates a thermal barrier to separate the inside of your building from the outside. Rigid insulation is often produced as rectangular-shaped boards that are installed in a modular fashion.
One way to define rigid insulation is by answering the question: What is rigid insulation not? Rigid insulation can be differentiated from other types of insulation by the following characteristics:
Dimensional Stability: Unlike beads, spray foam, or batts, rigid insulation holds its manufactured shape rather than conforming to its surroundings. This means it can be used outside the wall cavity since it doesn’t require a container to support it.
Compressive Strength: Other types of insulation like cellulose or fiberglass blanket carry virtually no compressive resistance, while polyiso rigid insulation boards typically boast a compressive strength of 20 psi or higher. This means you can walk on rigid insulation without damaging it.
Installation Method: Rigid insulation can be installed by fastening, adhering, or loose-laying modular boards to structural sheathing, studs, walls, or decking.
What is Rigid Insulation Made of?
Now that we’ve established a basic understanding of what rigid insulation is, let’s answer the question: What is rigid foam insulation made of? There are three main types of rigid foam insulation that you’ll see in the construction industry:
Expanded Polystyrene (EPS)
Extruded Polystyrene (XPS)
Polyisocyanurate (Polyiso)
Each of these rigid insulation types is made of different raw materials (resins and additives), and each one has its own manufacturing process. The final product comes out looking very similar for all three varieties of rigid insulation: rectangular 4’x8’ boards in various thicknesses ranging from ½” up to 6”.
Polyiso insulation contains an additional component that is not included in EPS or XPS. That’s because the manufacturing process requires a facer on either side of the foam. Polyiso consists of a foam core that is sandwiched between two facers. The facers are made of a material like foil or fiberglass-reinforced cellulose. EPS and XPS, on the other hand, do not require a laminated facer and have a homogenous makeup.
What is Rigid Board Insulation Used for in Construction?
Rigid insulation is versatile and can be used throughout the building envelope, including inside and outside of the wall cavity, roofs, attics, and foundations. Rigid insulation, like Rmax Durasheath®, is used on exterior walls under siding and wall finishes, on the interior of basement walls, and as protection to newly installed waterproofing on the outside of foundation walls for backfilling.
Rigid insulation is the go-to material in commercial roofing systems. It’s used to insulate the building from above and create a drainage slope on flat roofs. In fact, to meet current energy codes, many commercial roofs require more than five inches of rigid insulation above the roof deck and below the roof membrane!
Benefits: Why and What Rigid Foam Insulation is Best?
A clear advantage that rigid insulation has over other types is its ability to be applied in a continuous manner. Continuous insulation is when your insulating material goes uninterrupted across the surface of your building. Rigid insulation is inherently a continuous insulator.
Additionally, the boards are often applied in two layers. When installed this way, joints are staggered and there is less opportunity for leaks to occur through the insulation joints. If you’re looking for insulation that enhances your building’s energy efficiency, rigid foam insulation gets the job done, by achieving a thermal resistance of R6 per inch for polyiso rigid foam insulations like Rmax Thermasheath®.
For an even bigger boost in energy efficiency, polyiso rigid foam insulation has another major advantage. It can be laminated to air and vapor barrier materials so that it can be installed in a single application. The Rmax ECOMAXci ® Wall Solution combines a fire-rated polyiso foam core with a 12 mil foil facer. When properly installed with joints sealed, it can function as an all-in-one air and vapor barrier, plus insulator.
What is the Best Rigid Foam Insulation? Rmax Can Help You Decide
Save time and money now, and later on down the road, by choosing the right insulating material for your construction project. If you’re still not sure what the best rigid insulation for your building is, Rmax can help you choose the right fit for the job.
Reach out today to learn more!