Today’s blog post provides an overview of commercial roof coatings and their use with spray polyurethane foam roofing systems.
Roof coatings and spray polyurethane foam can serve different but complementary purposes. Reflective coatings can help reduce solar heat absorption, while SPF can provide insulation value as part of a properly designed roof assembly.
Commercial Roof Coatings and Their Value
Commercial roof coatings can provide both protective and reflective benefits when applied to a properly prepared and compatible roof substrate.
A liquid-applied coating can form a continuous protective surface over suitable roof areas. Many commercial roof coatings are available in white or other reflective colors that reduce the amount of solar energy absorbed by the roof.
A white roof coating can lower roof surface temperatures compared with a darker roof surface and may reduce cooling demand in some buildings.
Actual energy savings vary based on climate, insulation, HVAC efficiency, building use, roof construction, utility rates, and other factors.
Reflective Roof Coatings in Colder Climates
Reflective roofing can provide substantial benefits during periods when reducing solar heat gain is desirable. In colder climates, however, the overall energy effect can be more complicated.
A reflective roof may reduce some solar heat gain during the heating season. Whether this creates a meaningful heating penalty depends on factors such as climate, insulation levels, snow cover, building use, heating efficiency, roof orientation, and the overall roof assembly.
For that reason, the energy performance of a reflective roof should be evaluated based on the particular building rather than assuming that the same savings will occur in every climate.
Roof insulation and air-sealing performance also play important roles in overall building energy use. A reflective coating alone does not replace the need for an appropriately designed insulation and air-control strategy.
Don’t Forget about the Insulating Power of Spray Polyurethane Foam
When spray polyurethane foam is used as part of a roofing system, it provides insulation value in addition to the protection supplied by the roof’s surface coating.
Because SPF is spray-applied, it can form a continuous insulation layer over properly prepared roof areas and conform around penetrations, curbs, and other details.
When properly designed and installed, an SPF roof assembly may help reduce heat transfer through the roof. A reflective coating installed over the foam can also reduce solar heat absorption during warmer periods.
The combination can therefore provide both insulation and reflective performance, although actual heating and cooling savings depend on the particular building and climate.
Commercial Spray Polyurethane Foam Roofing Systems
Roofing Services
Our professional commercial roof contractors provide:
- Roof maintenance & repair
- Inspections & leak detection
- Energy efficient roof systems
- Complete roof replacement
- Roof life-extending solutions
An SPF roofing system typically consists of spray polyurethane foam protected by a compatible coating or other protective surfacing. Depending on the project, this type of assembly may provide several benefits:
- Roofing and insulation value in a single system
- A continuous insulation layer over properly prepared roof areas
- Reduced solar heat absorption when a reflective protective coating is used
- Potential reductions in heating and cooling demand depending on the building and climate
- The ability to conform around penetrations, curbs, and other roof details
- The ability to create or improve slope in properly designed applications
- Repair and recoating opportunities when the existing SPF system remains suitable
SPF roofing is not appropriate for every roof. Before installation or restoration, the existing roof should be evaluated for wet insulation, structural deterioration, drainage problems, damaged roofing materials, failed seams or penetrations, trapped moisture, and other conditions that may need to be corrected first.
The exact insulation value, coating performance, service life, application requirements, and warranty terms depend on the particular SPF and coating products selected.
Combining SPF with Protective Roof Coatings
The protective coating installed over an SPF roof is an important part of the complete system. It helps protect the foam from ultraviolet exposure, weathering, moisture, foot traffic, and other conditions.
The coating should be applied at the required thickness and maintained over time. Damage or deterioration should be repaired so the underlying foam does not remain exposed.
When the building and existing roof are suitable candidates, an SPF roofing system with a compatible protective coating may provide an effective combination of roof protection, insulation, and reflective performance.
A commercial roofing contractor can evaluate the existing roof and discuss whether SPF roofing, another restoration system, repair, recover, or replacement is appropriate.
