Roofers installing commercial roof insulation.

Do you notice extreme hot or cold areas in your commercial building? Is your HVAC system running constantly? The issue may actually be your roof’s insulation!

Insulation is installed under the roofing membrane (like TPO, PVC or EPDM) of a commercial flat roof to keep the building at a comfortable temperature, as well as to increase the building’s energy efficiency. So, if you’ve made an investment in a new roofing system, it’s important to know that proper installation with high-quality insulation materials is critical to a properly functioning commercial roof.

Types of Commercial Roof Insulation

There are a number of different types of insulation for commercial roofs. Each one has its benefits, and it’s up to your roofing company to make the best recommendation, based on factors like local building codes and the roofing materials being used. In addition to maintaining a constant temperature inside of a building, roof insulation also adds fire resistance and increases the durability of the roof, since it’s placed above the roof deck and just under the top layer of a single-ply membrane roof assembly.

Below are some of the most commonly installed materials for roofing insulation:

Mineral Wool

– Mineral wool is a wool-like insulation, made from minerals, with high fire and damp resistance.

Polyisocyanurate (Polyiso)

– Also known as insulation boards, polyiso insulation comes in rigid foam sheets and is compatible with single-ply, bitumen, and metal roofing.


– Commonly used, especially in residential settings, fiberglass has high fire resistance but loses insulative quality when wet.

Spray Foam Insulation

– Spray-on insulation can conform to non-regular surfaces and can only be applied in a certain temperature and humidity range.

Extruded Polystyrene (XPS)

– XPS consists of closed-cell foam boards that are made through an extrusion process.

Expanded Polystyrene (EPS)

– EPS is a lightweight board that can be shaped and molded. It is not compatible with petroleum-based adhesives and is not fire-resistant.

Since these commercial roof insulation options are manufactured products, a great advantage of many of them is that, as long as they are installed correctly, they have a warranty against defects.

What is R-Value?

R-value is the measurement used to rate the thermal resistance of insulation materials per inch of thickness. Different types of insulation products have different R-values, and a high R-value usually means a higher level of thermal insulation.

However, depending on your location in the United States, a high R-value insulation system may not be necessary.

Climate Zones

The lower 48 United States are divided into seven climate zones, with most of the state of Alaska in Zone 8. It’s important that your commercial roofing system has insulation with an R-value that’s appropriate for the zone that your building is located in.

Extra insulation may seem like a good idea, but too much insulation can cause damage to your roof due to thermal shock, in addition to being a waste of money.

TEMA Roofing Services: Your Entire Roof is Covered

TEMA Roofing Services covers all parts of your roof (whether you have one building with a low-slope roof or a portfolio of properties with multiple roofing types). We install only high-performance insulation and roofing systems that keep your building comfortable, along with keeping your energy costs down.

If your building is too cold in the winter or too hot in the summer, the issue may be your  commercial roof insulation. Call TEMA Roofing Services today for a free inspection!