Making The Most Of Metal Roofing’s Energy Efficiency
It’s that time of year again. Summer is approaching and, with that, homeowners are beginning to think about high energy bills caused by air conditioning costs. Metal roofing contractors have a great story to talk about in terms of energy efficiency but, when I train sales teams across the country, I often find that they are woefully lacking in the “why” and “how” of metal roofing energy efficiency. As a result, they are unable to properly educate homeowners on this great benefit of metal roofing, and they lose sales to other companies and other products.
The contractor who can best explain energy efficiency and make it “emotionally real” to a prospective customer will stand a great chance of getting the job. They will become the “expert” that homeowners are seeking when it comes to making wise decisions about their homes.
In this issue the the Executive Report, we’re going to explain exactly how the energy efficiency of metal roofing occurs. However, before we get into that, there are a couple of basic concepts that we want to explain
How Is Heat Transferred?
Heat is transferred in three ways. Radiation, Conduction, and Convection. Radiant Heat is the heat that passes through materials, or radiates off of materials. For example, if I am inside my home standing next to a window on a sunny day, I can feel the sun’s radiant warmth passing through the window glass and warming the air around me. Conductive Heat is the heat that transfers when one material, warmed by the sun, touches another material and conducts heat to that other material. For example, a tightly sandwiched roof system will conduct heat from the outer layer to the inner layer pretty efficiently. Convective Heat is the heat that transfers with air flow. Think of the fact that warm air rises. That is convection and, in terms of energy efficiency, we use it to our advantage when we ventilate attics, bringing cool outside air in at the eaves, and allowing it to warm in the attic and be carried out at the ridge.
Who Cares About Energy Efficiency?
This is a huge question, and its answer provides great fodder for helping homeowners understand that the importance of energy efficiency goes beyond just their pocketbook. In fact, some homeowners choose energy efficiency solely because they see it as being wise for the environment. They will quickly choose energy efficient products despite their higher initial cost. However, utility companies also care about energy efficiency. You may wonder why this would be the case. Doesn’t it benefit the electric company when they sell more energy? Not really. Utility companies have to build their infrastructure for energy output to be able to meet their peak demand day each year. For most companies, that is the hottest afternoon of the summer, usually sometime in mid August. Utility companies care more about summer energy efficiency than anything because, if they can reduce that peak demand point, they reduce their need to build infrastructure which isn’t used the rest of the year. The government also cares about energy efficiency in order to help our country develop a solid and forward-thinking energy plan. That is why they developed an Energy Star rating system for roofing – they fully understand the huge role that roofing plays in our country’s energy consumption. At present, homeowners in the USA who choose Energy Star roofing products can be eligible for a federal tax credit of up to $500.
So, with those basics in mind, let’s dig into the “how” and “why” of metal roofing energy efficiency. Knowing this information will help make you an expert who your prospects and customers will trust and rely upon.
How Can A Home’s Roof System And Attic Save Energy?
The first thing to respect is just how vulnerable a home’s roof is to the sun. While we often do things to insulate the walls of our homes, the roof is actually far more prone to the sun’s radiant heat than the walls are. The roof is often forgotten as a place to stop unwanted heat from entering a home. It’s important to help homeowners realize that energy efficiency from the top of their home includes much more than just insulation on their attic’s floor.
Why not take steps to keep the heat from ever entering the attic in the first place? Doesn’t that make the most sense? And, it starts at the roof.
Of course, if heat does get through a home’s roof, there is a second chance and that second chance lies within the performance of the home’s attic. Insulation is indeed used to stop heat transfer through the attic into the living space while ventilation is used to vent the heat back outside where it belongs.
Let’s Start At The Top…
For many years, homeowners in hot climates have used white or light colored roofs for their reflective nature. These roofs help to reflect radiant heat and reduce heat transfer into the attic. White roofs are an option for all homeowners but, in response to the fact that many homeowners do not want a light colored roof (plus, with most products, they gather dirt and lose their light color over time), much of the metal roofing industry uses reflective pigments in its paint systems. These “tweaked” reflective pigments help to reflect radiant heat even in dark colors. It is these pigments that have led to the US DOE Energy Star rating for many metal roofs. So, a light colored roof or a metal roof with reflective pigment in the coating will provide the best “first line of defense” against the sun’s heat.
Next, Let’s Look At Thermal Mass…
Any roofing material sitting in the sun will gather heat and become warm to the touch. For maximum energy efficiency, a roof needs to quickly shed that heat as soon as the sun goes behind a cloud or even when a gentle breeze blows. Products that have great thermal mass, though, such as standard composition shingles and tile, gather and hold that heat, continuing to radiate it into the home even hours after the sun has gone down. Aluminum roofing and steel roofing both dissipate heat quickly (think of that piece of aluminum foil and how quickly it cools down once you remove it from your oven). Therefore, it makes sense to have a roof that quickly sheds any gained heat.
What Is A Thermal Break?
Heat is transferred pretty efficiently by conduction. Again this means that one material gets warm sitting in the sun and anything that material touches also gains heat through conduction. One of the best ways to stop conductive heat transfer is with a dead airspace. That is known as a thermal break. It is the same concept that happens with double pane windows – the very tiny air space between the two panes of glass is adequate to stop heat transfer. So, while a metal roof may get warm to the touch, if we can minimize contact between the metal and the home’s structure, that is a good thing. This is done in a couple of ways with today’s metal roofs. First, metal roofs that are formed to look like shake, shingle, slate, or tile have an integral airspace between the metal and the roof deck, creating a natural thermal break. And, in the case of flat metal roofs that sit right on the roof deck, they can sometimes be installed on battens to create the thermal break between the metal and the roof deck. (Though battens do significantly increase job complexity as they raise the level of the roof – impacting dormer windows, gutters, downspouts, etc.)
Vent Out The Heat That Does Get Through…
It’s inevitable that some heat from the roof top will get through the roof system. In most residential construction, ventilation is the way to get that heat back to the outside. Ventilation is achieved by bringing fresh air in at the bottom of the roof and exhausting it out at or near the peak of the roof. As this air travels through the attic, it bathes the under side of the roof deck with fresh air, carrying both heat and also any moisture that has migrated into the attic away from the home’s living space. As much as possible, you want to think here about convective air flow and how to continually bathe the entire under side of the roof deck with fresh air. Metal roofs are designed to easily accommodate exhaust vents and there are also some integrated options to help increase intake vents if a home has limited intake venting.
Insulation on the attic floor serves as a final line of defense to help keep summer heat from entering the living space. This insulation is also perfectly located to help hold heat inside the living space during the winter.
What About The Winter?
A roof and attic system that perform well in the summer will also perform well in the winter. During the winter, there are two goals. One is to hold heat inside the home. This is done with insulation on the floor of the attic. The second goal is to vent out any heat and moisture that do enter the attic. This is done with ventilation. Good insulation and ventilation serve the purpose of helping avoid ice dams on the roof in the winter which result when heat from inside the home reaches the snow on the roof. Because of the need to vent attics in order to prevent ice dams, there is no “winter penalty” to energy efficient roofing – this reality goes against some of the published information that is available so it’s critical that you be able to thoroughly explain this to homeowners.
Special Circumstance — Conditioned Attics…
Increasingly, homes are constructed with conditioned attic spaces. In these cases, the entire interior surface of the attic is sprayed with closed cell urethane insulation which serves both as a vapor barrier to reduce moisture migration into the attic and as a high R-Value insulation. (Structural Insulated Panels, or SIPs, accomplish something very similar in terms of thermal dynamics.) This results in an attic that is not vented but instead is well insulated to prevent heat gain in the summer and heat loss in the winter. The downside is that insulating the underside of the roof deck can cause roofing materials such as asphalt shingles to age prematurely. That is not the case with metal though. Metal makes a great covering for fully insulated attics.
So What Savings Can Be Expected??
Every home is going to be different in terms of energy savings from a metal roof and proper ventilation. A lot depends upon their previous roof and attic system. A lot also depends upon their own personal habits when it comes to cooling their home. However, it is very common for us to have homeowners report summertime energy efficiency of 20% and even more after an energy efficient metal roof is properly installed. (And, again, a metal roof that is formed to have an integral airspace between the metal and the structure as a thermal break will always have great benefit compared to other metal systems.)
Make It Emotional
When promoting the energy efficiency of metal roofing, be sure to make it emotional for the prospect. Help them to understand that energy costs are only going to rise. Help them to understand that an energy efficient metal roof will make their home more comfortable and enjoyable. Help them to understand that only when their home is re-roofed can some very important things be done to achieve energy efficiency. Help them to “feel the pain” of a roof system that is not energy efficient. As I always say, people are willing to even go the to dentist when their pain level is great enough!
Need More Help?
Every situation is different. As a home improvement specialist, you will learn more from each and every job you do. Please call me at 1-800-543-8938, ext. 201 whenever I might be of service by helping you to properly understand and promote energy efficiency. I am happy to help with anything else as well!
Do You Have Ideas For Future Issues?
We hope that the information in this Executive Report helps you in your sales of residential metal roofing. It’s hard to believe but the Residential Metal Roofing Executive Report has been published for over two years now. While we have not yet come anywhere close to exhausting all of the ideas and information we can share, we’d love to hear from you. What would you like to know more about? What objections do you run into? What obstacles are in your way for achieving greater metal roofing sales? Please email them to me at email@example.com and we will answer them in future issues.
Home show season is in full bloom! Here are some ideas to make your home show booths even more effective at pulling in prospective customers – try choosing 3 or 4 and implementing them at your next show!
Todd Miller has spent his entire career in the metal building products manufacturing industry. He is president of Isaiah Industries, an organization recognized as one of the world’s leading metal roofing manufacturers. Todd is currently Vice President of the MRA (Metal Roofing Association) and a Past Chair of MCA (Metal Construction Association). Through his website, he strives to raise the bar on standards and practices to provide property owners with the best possible products for successful roofing projects.
You may pull quotes from this article provided you include a link back to the original article on this site. You may not reprint this full article, or even a significant amount of the article, without explicit permission. To gain permission, click here.