When constructing or renovating a building, finding the right thickness of rigid insulation is crucial for achieving optimal energy efficiency and comfort. However, there are a variety of materials to choose from—all of which have varying degrees of thickness.
Let’s take a closer look at rigid foam insulation, R-values, and the impact of insulation board thickness.
Understanding Rigid Foam Insulation
Rigid foam insulation is a popular insulation choice because of its excellent insulation properties and ease of installation. Here are the three types of rigid foam insulation:
Expanded Polystyrene (EPS)
Extruded Polystyrene (XPS)
Polyisocyanurate (Polyiso)
Although there are pros and cons to each type of rigid foam insulation, Polyiso is particularly noted for its high R-value per inch, making it one of the most efficient insulating materials to choose from.
What is R-value?
Before discussing rigid insulation thickness, it is critical to understand R-value.
R-value is a measure of how well rigid foam insulation boards block the flow of heat, usually listed in an R-value per inch format. Materials with high R-values, such as insulation, are very good insulators, whereas materials with low R-values, like metals, are good conductors and have the ability to move heat efficiently.
Determinants of Rigid Insulation Thickness
The thickness of rigid insulation is determined by several factors, including the climate of the area, the type of building, and specific energy codes.
The goal is to achieve the highest R-value in order to enhance the building's ability to retain heat during winter and cool air during summer. Higher R-values, however, typically result in higher building costs so it can be important to optimize the amount of insulation a building has.
For example, a material with a lower R-value (EPS) will require a thicker sheet of insulation to achieve the same level of insulation as a thinner piece of material with a higher R-value (Polyiso).
Thickness Guidelines for Different Applications
Depending where rigid foam board insulation is installed—residential or commercial buildings—there are different thicknesses of insulation required:
Residential
For residential applications, the typical thickness of rigid insulation ranges from 1” to 3”, depending on the part of the house being insulated. For basement walls, a thicker foam board is often recommended because of its high moisture environment and the need for greater energy retention.
Commercial
Commercial buildings, on the other hand, might require even thicker boards to meet higher R-value requirements and to address larger-scale thermal and moisture management. Homes and buildings located in colder regions often require thicker rigid foam insulation boards as well.
Polyiso Insulation: The Optimal Rigid Insulation Thickness
Polyiso is particularly effective due to its thermal performance and high R-value per inch. Many materials, as mentioned earlier, range from 1” to 3”, especially for residential buildings.
Polyiso, however, is has a rigid insulation thickness of 2” to 4”, which has the ability of providing an R-value of up to R-6 per inch—the optimal level of insulation thickness
Economic and Environmental Impact
Investing in thicker, high-quality insulation like Polyiso can provide significant long-term savings on energy bills. Environmentally, Polyiso contributes to reduced energy consumption and greenhouse gas emissions that support a more sustainable construction practice. Polyiso insulation even uses recycled materials in the manufacturing process, further increasing its sustainability.
Polyiso: Thin Foam, High Performance
Selecting the right thickness for your rigid foam insulation is crucial for optimizing the energy efficiency of your building. Installing the right amount of insulation keeps your building code compliant while also keeping costs manageable.
In addition, Polyiso offers a superior solution with its high R -value and robust environmental credentials. Always consult with a professional to ensure that your insulation meets local building standards and is installed correctly for the best results.
For help determining the right thickness of Polyiso insulation for your project, reach out to the rigid foam board experts at Rmax today!