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Flat Roof Insulation

Modern beautiful home with flat roof

Do you have a flat roof on your home? Are your heating bills unusually high? Your energy costs might be literally going through the roof! Installing the right flat roof insulation can help.


Flat Roof Insulation

Flat roofs are becoming a popular way to add an aesthetic touch to a modern home, and are the standard for many commercial and industrial spaces. However, flat roofs can pose challenges that homeowners don’t always expect.

One of those challenges is managing energy costs. The U.S. Department of Energy estimates that up to 70 percent of a home’s energy usage is dedicated to heating and cooling. A home loses 25 percent of its heat directly through the roof. An uninsulated roof can add up to some big heating bills, especially during the winter. The only way to counteract that, and keep your heat inside where it belongs, is good insulation. 

Unfortunately, insulating a flat roof is trickier than many people realize. Because of the unique shape of the roof, you’ll need to take some extra steps to ensure it’s done right.

Methods of Flat Roof Insulation

No matter how you proceed, flat roof insulation needs to be installed carefully. Because of the difficulty posed, we strongly recommend working with a licensed and experienced roofer. They will be able to advise you on which insulation method will work the best for your space, and they’ll make sure the work is done correctly. Improperly insulating your flat roof today can cost you thousands of dollars in repairs. If you aren’t an experienced roofer, save yourself the headache and call in the experts.

Interior Insulation 

One option for insulating your roof is the traditional method of placing insulation material between the roof and the ceiling. In order to make sure the insulation doesn’t cause further issues with the roof, it’s important to pick the right material for the job.

Unlike a pitched roof, which allows ample space between the roof and ceiling for ventilation to be installed, flat roofs are difficult to effectively ventilate. A poorly ventilated space that isn’t airtight allows condensation to gather, which can damage your roof. Insulation materials that trap moisture can exacerbate this problem. Flat roofs are also more prone to leaks. If a leak occurs, an absorbent insulation material will soak it up and be rendered useless. You can avoid this problem by using an insulation material that is less absorbent, such as spray foam or dense pack cellulose. Be sure to do your research and use a material that has the appropriate r-value for your home and climate. 

No matter what material you use, many people discourage interior insulation for flat roofs. Luckily, there is an easier option.

Exterior Insulation 

If interior insulation isn’t possible, or if it just doesn’t seem like a good idea, exterior insulation might be the answer. For this method, a layer of rigid insulation is placed on top of the roof’s weatherproof membrane, and then covered with another layer of weatherproof material. Rigid foam sheets are the best insulating material for this method. Two or more layers of foam sheets should provide an appropriate level of insulation depending on the r-value mandated for your roof. Review our blog post on tapered roof insulation

This method allows you to avoid condensation issues, and provide some additional weatherproofing to your roof as well. It also requires no ventilation, and is generally easier to install and maintain. Most roofers prefer exterior insulation for flat roofs.


Flat roof insulation isn’t an easy task, but it can be done. With a little bit of work, and some professional assistance, you can say goodbye to those high heating bills once and for all.

If you live in southwest Missouri, contact Taylor-Made Roofing for help with your roofing needs. Our experts can help you explore new roofing options, maintain an older roof, perform emergency repairs, complete tear-offs and recovers, and perform remodeling services. With over 20 years of experience in residential and commercial roofing, Taylor-Made Roofing is a company that you can trust. Our family-owned business offers quality services, a reassuring warranty, and free estimates. Give us a call at 417-326-8778 or contact us online. We look forward to hearing from you.

Fully licensed and insured, Taylor-Made Roofing is ready to take care of your roof.
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