Better for the Environment and Your Next Roofing Project

Choosing the right material(s) for your roofing project can be a daunting task, especially when working on projects chasing a LEED certification or adhering to any kind of sustainability standards. Even if the project isn’t seeking any kind of green certifications, the rise in demand for more sustainable construction practices and higher performing materials has skyrocketed in the last decade. So what are the best options?

One roofing material has been gaining popularity in the design and construction spaces and for all the right reasons. Insulated metal panels, or IMPs, are durable, easy to install, versatile and best of all, sustainable.

What Are IMPs?

Insulated metal panels consist of two sheets of metal that fully encase a center core layer of insulation generally made up of either foam insulation or mineral fiber insulation. This sandwich-style design often removes or reduces most of the common disadvantages of layered building systems including cost, time, thermal performance, fire-rating and sustainability. Most building components are multi-layered, meaning they are all separately pieced components that get put on individually. IMPs have the air barrier, moisture barrier and insulation built right into one compressed air-tight system.

IMP Performance, Time and Labor

Because IMPs are an all-in-one system, they are faster to install, save on labor costs and speed up the install period for the roofing since there is one piece being installed as opposed to several pieces being installed separately in layers. This one-component approach is generally faster and cheaper to use, but also typically has better barrier performance too. Instead of having to install the air/vapor barrier, insulation and then panel with two or three passes around the building, IMPs takes the place of all three.

Multi-component systems rely not only on proper installation to make them effective, but also material choice. With traditional systems you’re fastening through the air/vapor barrier opening up yourself to the potential of leaks if all punctures into the air/vapor barriers aren’t sealed properly. Many of these traditional insulation systems are made with materials that will hold water if moisture reaches it. Fiber or paper-based gypsum materials will retain water and either mold or deteriorate quicker if the moisture barrier is not properly installed or fails. 

Design Advantages with IMPs

IMPs perform great, but also look great and for longer. Metal roofing has long been regarded as a superior choice for its durability and low maintenance, but options only go so far with how heavy some metal roofing systems can be. The strength-to-weight ratio of IMPs gives you the same durability, but at a much lower weight with more flexibility.

Since IMPs generally have a lower weight-to-size ratio, roofing projects can have longer panel runs covering larger areas faster with fewer panels and without the added structural support/costs. Because of this, they are also an ideal choice for low-sloped roofs and larger-scale roofing projects like warehouses or production facilities, industrial buildings, or schools. The longer panel lengths offer a seamless look that can be carried throughout the project since IMPs can also be used for exterior wall cladding. This continual look has been a more recent and modern design trend that lends to the desirability of IMPs being used for both facades and roofing together. 

Most IMP manufacturers offer performance-based coatings, several aesthetic options and an extensive range of color and finish options. IMPs can be installed in either vertical or horizontal panel orientations and can be used in almost any climate. The durability of IMPs offers long-lasting protection from the elements with weather resistance in hot, cold, salty and wet regional conditions.

IMPs Can Help Sustainability Goals

IMPs aren’t just a great choice for the look and cost, but also for the environment. Sustainability and waste have been a recent driving force when engineering and constructing buildings and as research and technologies advance, the push for sustainability has growing significantly. More and more projects are chasing LEED certifications, and building codes have stricter requirements. Whether the roofing project you are working on is trying to reach a green building metric, or is just looking to meet the ever-so-strict building codes, IMPs might be the way to go. 

Since IMPs are two layers of metal encapsulating an insulation core, the thermal performance is higher than that of traditional roofing materials alone. IMPs have been engineered specifically to provide better insulating properties, effectively reducing heat transfer and heat loss due to thermal bridging or thermal drift. These not only regulate the temperature consistency inside the building, but significantly reduce energy costs for heating and cooling the inside of the building. Since heat rises, choosing a roofing material with superior thermal performance is essential for projects emphasizing sustainability and energy efficiency.

Understanding R-Values

When considering sustainability and thermal capability, IMP performance is often measured and given what is called an R-Value. The insulation cores of the metal panels drive the bulk of the performance metrics and are made up of either a dense foam core or a mineral fiber core. The panels are given a rating based on the material’s thermal resistance to the flow of heat. This performance rating is the R-Value. The higher the number is for the R-value, the higher the thermal resistance is. Insulation thickness can often be raised in order to meet specified thermal conditions or sustainability requirements for a project.

In addition to the thermal performance, IMPs are often made from recycled materials, have a great fire rating and greatly reduce construction costs. The energy used to produce the metal in IMPs is offset by the decades of use a building will get from them. IMPs are also recyclable, which helps with the concerns about depleting metal resources and just general carbon emission strains. Knowing this material has utility beyond its initial use brings the product lifecycle virtually full circle.

What is LEED and Why is it Important?

LEED stands for Leadership in Energy and Environmental Design. It is a professional, accredited, green building rating system and certification handed out at a projects completion. It is the most widely used green rating system and standards in the world with the goal of promoting sustainability and ensuring buildings meet their defined framework for healthy, highly efficient, and cost-saving green buildings. 

To achieve a LEED certification, a project earns points by adhering to prerequisites and credits set by the USGBC which address top sustainability metrics like carbon, energy, water, waste, transportation, materials, health and indoor environmental quality. Projects go through a verification and review process by Green Business Certification Inc. (GBCI) and are awarded points that correspond with various calculated totals at different LEED certification levels. 

IMPs are a great roofing system choice because of their recyclability, durability, generally lower construction costs, building efficiency and overall thermal performance. These metrics typically meet or exceed benchmarks for energy efficiency codes and green building standards, contributing directly to LEED certification credits. Overall, IMPs might be worth the consideration for your next roofing project.

ABOUT THE AUTHOR: Kyle McGinnity, is senior project estimator at MG McGrath, Maplewood, Tennessee. For more information go to www.mgmcgrath.com.