The use of white, solar-reflective coatings often proves beneficial in reducing roof temperatures and contributing to lower cooling-energy demand.
But the application of such coatings has allegedly caused some very non-beneficial—and unwanted—effects when applied to a number of asphalt-shingle roofs in Florida, based on a news report on complaints lodged with the utility company Florida Power & Light. The coatings are being blamed for leaking and deteriorating roofs.
The South Florida Sun Sentinel reports that Florida Power & Light (FPL) reimbursed contractors to paint asphalt-shingle roofs white to reflect sunlight—“against the advice of the federal government and major roofing manufacturers.” FPL has provided rebates as part of a program to encourage customer actions to reduce electricity use and costs.
The Sun Sentinel story can be read at FPL sued over program aimed at saving energy.
“About a dozen FPL customers have complained to state regulators that their roofs started to deteriorate or leak after they were coated,” the newspaper reported. “And five others in South Florida filed a lawsuit against FPL and the contractor who did the work. Others have complained directly to the utility or contractor, according to court records.”
The report said FPL has provided rebates for application of white coatings to some 4,700 asphalt roofs. The funds are generated by conservation charges on electricity bills.
Complaints included reports of leaking roofs, with one homeowner saying paint trapped water in the shingles, causing the nails to rust and water to seep in.
Jackie Anderson, an FPL spokeswoman, told Durabilty + Design that complaints have come from only a “handful” of customers. She said customers make arrangements with independent contractors, who are responsible for the work and for complying with building codes. “We provide incentives to help with the cost,” she said.
“We’re conducting a thorough investigation of the claims, but the matter is in litigation, so we really cannot comment further,” Anderson said.
The newspaper report says painting shingle roofs “has never been recommended or approved by the federal Department of Energy, which also promotes energy conservation,” and adds that the Asphalt Roofing Manufacturers Association (ARMA) warns against applying elastomeric roof coatings to asphalt shingles.
“Problems reported after asphalt shingle roofs have been field coated include unsightly curling and/or cupping of the shingles, which may lead to premature failure and leaks,” the newspaper said, quoting an ARMA technical bulletin. “The paint can trap moisture and make the shingles rot.”
But opinions on the issue are apparently not universally agreed upon. The Solar Reflective Coatings Council, part of the Roof Coatings Manufacturers Association (RCMA), says in a “Frequently Asked Questions” discussion of solar-reflective roofs that white, reflective coatings can be applied a wide range of roofing surfaces, including “certain kinds of asphalt roofs.”
“White coatings can be applied to practically any roofing surfaces, membranes, or substrates,” the FAQ section of the Solar Reflective Coatings Council’s website states. “They are commonly applied to sprayed polyurethane roofs to provide waterproofing. They can also be applied to metal roofs, single-ply rubber roofs and modified-bitumen roofs. They can even be applied to certain kinds of asphalt roofs.”
The document adds, however, that “It is important to establish compatibility between the white coating and the underlying roof membrane.” See FAQs on white roof coatings.
The Sun Sentinel report said coatings were applied to 4,711 asphalt shingle roofs, including 1,004 in Broward County and 1,948 in Miami-Dade County, from 2007 to 2009, according to court documents.