Rigid Foam Insulation: A Quick Guide
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There are many options for insulating a building and a deluge of information you must sift through to decide. What kind of insulation is there? Are some forms better than others? Will it work for my climate? How would it affect my budget? The variations can make the decision-making process challenging.
At InSoFast, we are dedicated to providing our customers with the best energy efficiency and conservation through continuous insulation. This blog will discuss the basics of continuous insulation using rigid foam insulation, from benefits to application.
Once you understand the principles of how rigid foam insulation works, we’ll talk about the InSoFast All-In-One Continuous Insulation & Framing System and how you can benefit from its advanced features.
Ready? Let’s begin!
What Is Rigid Foam Insulation?
Rigid foam insulation, also known as foam board insulation, is a type of continuous insulation made from rigid plastic foam that’s applied to the walls of buildings before siding is installed.
Strong, durable, and resistant to water and pests, rigid foam insulation can also function as an air barrier if the foam boards are adequately sealed. You’ve probably seen foam insulation boards when you pass by construction sites—the most common are the pink or green panels mounted to the walls of buildings still under construction. The term “continuous insulation” comes from panels wrapping around a building like a shell, eliminating thermal bridges, weak points, or areas where heat passes through materials meant to insulate the building.
There are other materials used in continuous insulation panels, but we’ll mainly discuss the three primary types of foam board insulation:
Expanded Polystyrene (EPS)
Made using heated and expanded polystyrene foam beads that fuse together, EPS foam boards have naturally occurring voids between the beads. The voids increase thermal resistance, and combined with low cost, ease of manufacture, and environmentally friendly properties, make EPS very attractive as an insulation material. EPS can be encased in different laminations, making it versatile for roof, wall, below-grade, or foundation insulating applications.
Extruded Polystyrene (XPS)
Also made from polystyrene but made with a different process, XPS has a closed-cell structure generated from the extrusion process. The closed-cell structure gives XPS higher compressive strength, better water resistance than EPS, and higher insulating properties than EPS. The extrusion process gives XPS a noticeably smoother top and bottom surface compared to the surface of an EPS foam board. XPS is typically used in walls or below-grade applications.
Polyisocyanurate (Polyiso)
The third common type of rigid foam board is Polyiso (also known as ISO). Polyiso and XPS are similar in that they are both closed-cell foam types. Technically, it is not a foam board; it starts as a liquid foam sprayed against a substrate to form a rigid panel. Made from a different plastic polymer, polyiso responds to heat by charring. In contrast, EPS and XPS will soften and melt, allowing Polyiso a higher fire resistance level than other foam plastic insulations. Polyiso not only offers better fire resistance, but it also has enhanced strength and thermal resistance. Polyiso is a high-performing and ideal choice for roofing applications.
Benefits of Foam Board Insulation
Rigid foam insulation has become a common home insulation material for many years. Property owners favor rigid foam insulation because it offers many advantages:
Prevents Air Leaks
When appropriately installed, foam board insulation fills in all the cracks and crevices around your house to create an impenetrable barrier against outside air, keeping your home comfortable year-round. Foam board insulation does this well because it’s easy to cut to fit snugly around irregularly shaped openings, unlike traditional fiberglass batting, which can leave gaps and holes.
Controls Moisture
Moisture and wood do not mix. Damp wood can lead to wood rot and, worse yet, mold and mildew growth, which is a severe health hazard. Rigid foam installation mitigates moisture issues by creating a vapor barrier, stopping moisture from entering your home. This is crucial in houses built on slab foundations, where moisture can be a constant problem.
Reduces Noise
Depending on the specific product and its thickness, properly installed foam board insulation helps reduce noise levels from inside and outside your home by absorbing sound waves. Generally, extruded polystyrene (XPS) or expanded polystyrene (EPS) has an STC rating between 37 and 57, enough to reduce the noise of that 5 a.m. garbage truck, or the blare of your budding rock band career. However, it’s important to note that rigid foam board insulation is primarily used for thermal insulation rather than soundproofing.
However, no insulation method is perfect, so let’s talk about the disadvantages of rigid foam insulation next.
Disadvantages of Rigid Foam Insulation
As appealing as using rigid foam insulation can be, consider these disadvantages:
Not Fire Resistant
A significant downside to rigid foam insulation is that it is not fire-resistant, so consider this if you live in a more fire-prone area. Because rigid foam is made from petroleum products, it will give off toxic fumes as it burns or melts, which is a severe health hazard. Of course, in a fire, you’d want to evacuate immediately, so exposure to these toxins will likely be minimal.
Can Be Difficult to Install
Those massive, lightweight foam panels are not easy to install, especially as a do-it-yourself project. Unlike fiberglass batting, which even an amateur can quickly cut and fit into place, rigid foam boards need to be carefully measured and cut precisely, which can be a time-consuming and frustrating process with little room for error.
Expensive
Rigid foam may be an excellent insulator, but it might not be the best choice if you’re on a budget, as it’s one of the more expensive options on the market.
Now that we’ve discussed the pros and cons of rigid foam insulation, let’s examine how to apply it.
Applications of Rigid Foam Insulation
Rigid foam insulation products are generally sold in sheets of 4 foot by 8 feet (the same size as plywood). They come in several different thicknesses ranging from ½ inch to 2 inches. This gives rigid foam insulation the versatility to be installed in various applications:
1. Walls
Rigid foam is often installed in walls to provide thermal insulation because it’s ideal for reducing heat transfer between a building’s interior and exterior.
Traditionally, wall insulation installation occurs between wood stud walls using fiberglass batts. However, the thickness of this cavity space can limit the insulation’s effectiveness. Because of this, some homeowners add continuous insulation to the outside surface of the studs, as adding one inch of polyiso insulation can add R6 to the thermal resistance.
2. Roof, Attic, and Crawl Spaces
The ability to quickly cut rigid foam boards to fit is why builders often use this to prevent heat loss or gain through a building’s upper surfaces. Sealing the panels also provides some protection against moisture buildup in these spaces.
Rigid foam insulation is also an excellent choice for insulating conditioned attics or retrofitting an attic space into a conditioned attic.
3. Under-slab Insulation
Some Rigid foam insulation can even be installed beneath concrete slabs (such as basement floors) to provide thermal insulation and prevent heat loss to the ground. In some climate zones, building codes require a minimum insulation standard, so the properties of rigid foam insulation are ideal for these requirements.
As we’ve seen over the past few paragraphs, rigid foam insulation is a very useful and versatile medium for insulating your home or business. Can rigid foam insulation be improved? Absolutely – that’s why the InSoFast system was invented!
The InSoFast System
Born from experiences in the ICF industry, InSoFast combines the benefits of ICFs (Insulated Concrete Form), which are continuous insulation and built-in studs. InSoFast is easy for DIYers while addressing issues that concern the building science community, such as insulating properties and sustainability.
How does InSoFast combine the benefits of ICF?
1. Interlocking Panels
Unlike flat-edged rigid foam panels, the edges of InSoFast panels are keyed, so they interlock like ICF blocks, making them easy to install. The interlocking panel design also provides a seamless thermal barrier that minimizes energy loss, enhances comfort, and improves overall building performance.
2. Ease of Installation
Why work so hard? InSoFast panels can be glued or screwed https://www.kgraberco.com/icf-construction/ directly onto your wall studs – and even over existing drywall or plaster! Use your existing insulation as an additional barrier, further creating more insulation!
3. All-In-One Design
Conventional rigid foam board requires, in addition to the board insulation board itself, a rain-screen drainage mat, two sets of fasteners, flashing tape, and furring tape to install properly. InSoFast eliminates all of the additional materials needed, so all you need to do is attach the panel using glue or screws.
4. Low Profile
Although inspired by ICF, InSoFast panels are thin – at 2 inches, making it an ideal choice for indoor insulation projects.
5. Install Almost Anywhere
You can use InSoFast for your walls, whether in your basement or above grade, floors, walls, or ceiling – InSoFast can also be installed as an exterior insulation layer!
6. Perfect for Insulating Shipping Containers
Whether you’re insulating a container for your storage needs or you’re considering converting a container into an office or home, our CX44 panels will convert your container into a comfortable, habitable space!
7. Integrated Wall Studs
InSoFast panels come with integrated wall studs made from polypropylene plastic and can be nailed, screwed, or glued. The studs will not split, rot, rust, or lose strength over time and can hold a massive amount of weight!
8. Built-in Electrical Raceways
Forget cutting into the drywall or installing cable covers to hide electrical cabling. InSoFast panels have built-in electrical raceways through which you can run your cables, making it perfect for creating a basement movie theater.
Conclusion
We hope this blog helps you warm up to the cool features of continuous insulation and how InSoFast can enhance and improve your installation experience.
At InSoFast, our motto is “Why work so hard?” and our customers agree! Our patented system is a cut above not just because of our advanced design but also because it simplifies your work, letting you complete your project faster to make the most of your building sooner.
Contact us today and let InSoFast be your insulation provider!
