By Kathy Danforth / Published March 2016
Whether hidden on a high rise or capping off your community’s statement of style, roofs are essential. With the high cost of replacement, homeowners and associations are learning that a combination of new products and catching problems early to prevent ongoing damage can extend the life of a current roof well beyond its original, expected life. Mike Shephard with Advanced Roofing and Sheet Metal shares, “The direction of the roofing industry is toward long-term maintenance and coatings. The return on the dollar is huge for roof maintenance.”
Flat roofs and sloped roofs present different challenges and options for types of roofing and maintenance. “Flat roofs are a little harder to maintain because pitched roofs shed water,” says Stella Amador with Florida Quality Roofing. “The warranties and types of materials used are different. What we recommend for repairs or replacement depends on the foot traffic on the roof, number of air conditioners and penetrations, and what roof is in place and its condition.
“The built-up roof (BUR), with multiple layers of asphalt and fiberglass plies and modified bitumen, has been the industry standard for flat roofs,” notes Amador. “Rolls of asphalt felt roofing, which is a mixture of synthetic and organic material, may be self-adhering or may be applied with hot or cold asphalt. The number of layers and slope of the roof will influence the warranty and level of water resistance.”
Shephard reports, “Modified bitumen is very tough and may be the best choice for roofs with lots of air conditioners and foot traffic. It has been proven to last more than 20 years and now has a No Dollar Limit (NDL) warranty on workmanship as well as the product, unlike warranties with a prorated, decreasing value. The manufacturer inspects the installation and ‘owns’ it, but—very importantly—almost all NDL warranties require regular maintenance and inspections. A small leak that is undiscovered can lead to massive damage and failure.”
Shephard is currently working on a project that could have been avoided. “We began installing a new roof today on a condominium, which had a seven-year-old modified bitumen roof that had failed completely. The membrane on top appeared perfect, but water had been seeping in; because it had a poured-in-place concrete roof, the water ran under the roof until about 70 percent of the roof was saturated when the water finally found a place to leak in. Because of a single leak, the whole roof was compromised. They can leak for a long time before you know you have a problem, so a roof with poured concrete should get a thermal moisture scan annually.”
Shephard observes, “In the last three to four years, thermoplastic olefin (TPO) roofing has overtaken and surpassed modified bitumen in the flat roofing market. Now TPO has 70 percent of the flat roofing market for new or reroofing projects. TPO is significantly less expensive and is energy efficient because it is a white, reflective material,” Shephard notes. “Installation is fast and quiet with no smell, no torch, and no flames. If a reroofing is needed, it can often be installed over modified bitumen without a tear-off by adding a substrate layer. Its weakness is that the details and flashings have to be perfect since there’s only one layer and one chance to seal it. NDL warranties are available with the same requirements for maintenance.”
The main causes of failure for flat roofs are lack of positive water drainage and lack of proper maintenance. “If the roof doesn’t drain properly because of clogged drains, there aren’t enough drains, or it isn’t pitched properly, premature roof failure results,” comments Amador. “If a flat roof doesn’t drain properly within 48 hours, there will be a weathered pattern, and the roof will begin to deteriorate rapidly.
“We recommend that associations limit access to their roof with locked doors and signage, and also keep a log book of all foot traffic.” Amador advises. “Sometimes unit owners have their own air conditioner repairman on the roof, and unbeknownst to them the contractor may cause damage by dragging equipment, dropping items that puncture a membrane, or leaving debris. Building maintenance personnel can help prevent this if they escort tradesmen. For added protection, it is a great idea to add walk pads and designate walk areas.
“The most important factor in extending a roof’s life is maintenance,” according to Amador. “This includes checking that drains are not clogged, flashings and all penetrations are waterproofed, pitch pockets are filled, and nothing is holding water. Often communities think that if they have a new roof they don’t need to worry about it, but the sooner maintenance begins, the longer the roof can be guaranteed. A 20-year roof life expectancy may be increased up to 30 percent longer with proper maintenance. Each manufacturer specifies the maintenance and documentation needed to not void the warranty.”
When a roof is nearing the end of its lifespan, restoration is often an option instead of replacement. “The most successful restoration we have seen is silicone roof coating,” Amador states. “If less than 25 percent of the roof has moisture, as determined by an independent survey, then the wet areas can be located, removed, and repaired; and a coating can be applied.”
Victor Monisera with Rhino Roof Protection Coatings, Inc., observes, “Most people who get a new roof could have applied a silicone coating for less than a third of the cost of a new roof. The silicone is better than a new roof because it resists ponding water; water doesn’t get in because it’s one solid, monolithic membrane. The silicone doesn’t crack like tar, and there are no seams that can lift up.”
Depending on the previous roof and other factors, Monisera points out, “Silicone coatings also can reduce the temperature on the roof by up to 75 degrees. This, in turn, reduces the temperature on the upper floors by 6–10 degrees. Silicone coatings are rated by Energy Star, the Cool Roof Rating Council, and other energy conservation programs.”
Shephard relates, “Florida Power and Light has offered rebates on reflective coatings at times. Environmentally, if you coat and maintain a roof, you can avoid tearing off massive amounts of roofing and insulation and sending it to the landfill. With a modified bitumen roof, as it reaches its 20-year warranty, it can be coated at one quarter the cost of a new roof and receive a 10-year warranty. If you do maintenance and coatings every 10 years, this can continue indefinitely.”
Though the battle and solutions are much the same for sloped roofs, the options in roofing systems are more varied. Most leaks occur at valleys or penetrations, due to the quality of materials and aging. “The most basic and least expensive material is a three-tab shingle, which will withstand winds up to 60 mph,” shares Amador. “Dimensional shingles can withstand winds up to 130 mph and have a significantly different warranty. An important issue with shingles is washing them with an organic wash rather than harsh chemicals. Aesthetically, people want to remove the black stains that algae forms, but the roofs can be vulnerable because they are asphalt-based with granules. However, with proper installation and high-quality materials, we can offer five-star warranties that cover workmanship for 25 years backed by the manufacturer.”
Shephard adds, “In Florida, most shingles are going to last 18–20 years regardless of what they are rated for, so there is no gain in paying for a higher rated shingle for longevity alone. Shingles are predictable, with a good track record, but environmentally they are weaker because the darker colors absorb heat into the deck and attic space.”
Monisera advises, “Asphalt shingles are only covered by insurance for 10 years because the grit starts coming off so the material cracks. Once it has a silicone coating, insurance can be reinstated—again, at under one-third the cost of a new roof. The lighter the color of the coating, the more the roof temperature will be reduced. However, even darker coatings are UV reflective and lower roof temperatures.”
Tile roofing provides an attractive option that can be quite durable. “It is the underlayment, not the tile itself, that provides the waterproofing,” Amador explains. “Concrete or clay tile can last up to 50 years, but the underlayment determines the life span of the roof. If the underlayment becomes brittle and cracks from the building shifting, there may be leaks even if the top tiles are intact. The other issue with tile is the method of attachment, which is either by using foam or by nailing holes through your waterproof barrier (mechanically fastening the tiles). We always recommend foam, because it does not puncture/rupture the tile underlayment and also withstands high winds.”
Shephard notes, “Tile has air space underneath, which helps to cool the roof better than shingles.” A consideration in reroofing projects is that shingles can be used to replace tile, but not the converse. “You usually can’t put standard tile on a shingle roof because the building was not designed for that weight.”
Monisera advises, “When pressure washing, water will soak into the tile that is not coated. Using water at 3000–4000 psi will break and chip tiles. When we apply a silicone coating, we repair the tiles, use silicone caulking around the vents, and put elastomeric patching that expands and contracts in all the cracks. Then, we apply primer and two top coats of a coating product from Australia. With this, the roof cleans itself as the water rolls off, and the silicone coating is algae and mildew resistant so no pressure washing is needed.”
“Metal roofs are similar to tile in lifespan—up to 50 years—and again, the underlayment is the most important aspect in determining how long the roof actually lasts,” Amador states. “The underlayment may be similar to a flat roof; some are manufactured with a non-woven polyester mat to last longer, and some are a mineral surface, which are constructed on a fiberglass mat. The most common underlayment is fiberglass, which is easier to tear. The environmental location is also a factor with metal roofs as only aluminum should be used near salt water, such as oceanfront properties. Different profiles of metal roofs include standing seam and 5V Crimp. The standing seam has hidden screws with a clamp, while 5V Crimp has exposed screws that may rust or pop up.”
Shephard recommends metal roofs as the longest lasting and most wind resistant of the pitched roofs. “My personal favorite is stone-coated steel tile,” he shares. “It has the beauty of tile with the strength of steel. And because it’s light, a shingle roof can be converted to steel tile. Like concrete tile, it lets air move underneath, and it comes in reflective colors. Most people don’t know when they have seen stone-coated steel tile because it looks like other tile.”
Monisera shares, “Metal roofs can be coated with varied colors of silicone coating or with a clear coating. If an aluminum roof oxidizes, it can be repaired and coated rather than removed. We are coating a lot of new roofs of different types, so they don’t have to be cleaned as often,” Monisera points out. “Roof warranties may be based on no one walking on the roof, so if workers are up there to pressure wash, that may break a tile and void the warranty. If the roof is a variegated shingle, the owners may choose a clear coat to preserve appearance, but a big advantage is that these coatings don’t require such frequent cleaning.”
“Steep roofs will have to have gutters and drains cleaned out, but associations should be very careful with pressure washing,” advises Shephard. “Associations should seek out companies that employ a soft washing technique by using environmentally-sound products and avoiding high pressure spray. Once a roof is clean, there are products that will prevent mold and algae growth if applied every other year. That avoids the issue of people walking on steep roofs, wallowing fastener holes, and starting a leak.”
As communities combine the advantages of maintenance and new products, budgets and the environment will come out ahead. “Consumers are becoming more educated and coatings are becoming popular, so tear-offs are becoming less common,” Shephard relates. “We have a roof in Naples that I installed 33 years ago, and we’ve performed maintenance since then. With coatings, we renewed the warranty for another 10 years six months ago. That’s my vision of a permanent roof!” If you like your current roof, with a relatively modest investment you can probably keep it!