Energy efficiency must be built into the design phase of a project in order to capture the best numbers. Usually, increased energy efficiency is accomplished by adding continuous insulation to a building’s enclosure (the walls and roof), which helps maintain a constant temperature so that heating and cooling equipment can run efficiently. However, one factor that can throw off your efficiency numbers, if left as an afterthought—is thermal bridging.
What is Thermal Bridging?
Thermal bridging is a phenomenon that can happen when you use materials on the building envelope that have different insulating values. This allows heat to escape through the material with the lower insulating value (higher conductivity), despite it being surrounded by a high-insulating material.
An example of thermal bridging includes insulation that is secured with screws. The insulation has a high thermal resistance, also known as R-value. Construction screws, which are usually made of metals like galvanized, stainless, or carbon steel, have high conductivity and no thermal resistance. That means that your building’s insulating value can be compromised when insulation is interrupted by metal.
Thermal Bridging in Walls Reduces Energy Efficiency
Since a building’s walls make up the largest surface area for heat to escape the enclosure, it’s critical to address and reduce thermal bridging in the wall design. In the past, buildings were often insulated only between the wall studs. This creates a major thermal bridging concern since there is a direct and continuous path for heat to escape along the entire height of the building—from the ground up. Thermal bridging in walls must be reduced in order to design more energy-efficient structures and meet energy code requirements.
How to Prevent Thermal Bridging in Walls
By utilizing the right system design, you can significantly reduce the impact of thermal bridging on your building. Using continuous insulation is one of the most effective design methods to prevent thermal bridging in walls. Continuous insulation means that insulation is installed at a constant thickness across the building’s surface without interruption.
You can take thermal bridging solutions a step further with a few other tactics. Minimize thermal conductivity further in your walls by installing continuous insulation with adhesives rather than screws or channels. Alternatively, if you prefer to loose lay your continuous insulation between supports, there are specialty girts on the market that are made of a non-conductive hardened polyurethane material that can completely eliminate thermal bridging in the wall system.
Polyiso is the Solution to Thermal Bridging
Selecting the correct type of insulation for your wall system is vital to maximizing your energy efficiency and minimizing your risk of thermal bridging. Rmax polyisocyanurate is the ideal material to use for continuous insulation on walls and roof systems. Here are some of its benefits:
Superior R-Value
Polyisocyanurate has one of the highest R-values (insulating value) of any building insulation type available. That means you can use a thinner and more manageable thickness to reduce material costs, but also achieve a well-insulated envelope at the same time. Rmax Durasheath®, which is a basic polyiso for continuous wall applications, boasts a minimum R-value of 6 per inch of thickness. Rmax ECOMAXci® has an enhanced R-value of 6.5 per inch.
Dimensional Stability
As you install continuous insulation to reduce thermal bridging, you’ll need a material that is stiff enough to hold its own. Unlike fiberglass, which requires paper backing and has no dimensional stability, polyiso is rigid and can be securely attached on the outside of the building structure to form a continuous layer of insulation.
Continuous Surface
Minimize air infiltration and leakage with continuous insulation with sealed joints between pieces. The facers of Rmax’s polyiso insulation are made of a variety of materials (paper, foil, or fiberglass-reinforced), which are all compatible with sealing and flashing tape that is designed to reduce heat loss and air movement at the joints and penetrations. The smooth, continuous surface is ideal as an underlayment for air barrier and cladding.
All-in-One Underlayment Options
Save time with installation and money on adhesives with Rmax ECOMAXci® Wall Solutions. This all-in-one polyiso air barrier product takes care of continuous insulation, underlayment, and air and vapor barrier for your walls so that they are ready for exterior cladding in a single step. This product features polyiso foam core insulation with heavy-duty aluminum facers for a superior reduction in thermal bridging.
Rmax Polyiso Extends Beyond Thermal Bridging
Rmax polyiso is a solid choice when designing commercial buildings with high-performance wall assemblies for maximum energy efficiency. The construction industry is constantly improving products to meet advancing building code requirements and to make installation faster and easier for contractors.
Rmax provides a specialized selection of high-quality building materials to tailor to your project’s specific design needs. Reach out to our experts today to help you find the right Rmax polyiso product for your building.