The Impact of Weather on Commercial Roofing Sealants, Adhesives, and Flashing
Your roof isn’t invincible, neither are its sealants, adhesives, caulking, and flashing. Wild weather and prolonged UV exposure can accelerate wear, compromising their effectiveness and waterproofing ability. Deterioration, delamination, cracking, and loosening may start as small problems but can accelerate quickly into extensive damage and pricey repairs.
What Do Sealants, Caulking, Adhesives, and Flashing Do?
These roofing materials, along with field membrane or metal, prevent water infiltration at potential leak points. Sealant and caulking are often used wherever different roof components meet (think seams, flashing, penetrations, fasteners, etc.). Adhesives attach insulation to the deck, bond layers together, and attach insulation to cover board. It also secures flashing and seals seams and joints. On adhered single-ply roofs, it can bond the waterproofing membrane to the cover board/insulation as well.
Flashing seals gaps and joints where the field of the roof meets skylights, curbs, parapet walls, roof penetrations, and at the roof’s edge. “The purpose of flashing is to waterproof,” explains Dan Edie, Service Field Office Manager, D. C. Taylor Co., Concord, CA. Flashing can be metal, single-ply membrane, or even liquid. For penetrations, either premanufactured flashing (such as boots) or field-wrap flashing will be applied depending on the shape of the pipe it’s being fitted to.
How Much Damage Can the Weather Cause?
Heat and UV. Even though they were made to be used outdoors, high temperatures and direct sunlight (UV rays) can degrade these materials and diminish their waterproofing ability. Sealants can dry out, adhesives may soften, and EPDM and modified bitumen roofs may shrink, causing flashing to pull at curbs, penetrations, and walls. “Sometimes flashings will start to get brittle and crack,” says Edie.
Cold and ice. Freezing temperatures can exacerbate clogged drains, making ice back up and breaking the seal of the roof, as well as damaging curbs and flashing. Cold can also make metal flashing brittle. Heavy snowfall can be problematic too as it adds weight to the roof, potentially straining flashings.
Temperature swings. When the temperature changes radically, thermal shock results. This can affect older roof membranes nearing or past their intended life. Potential damage to the base of roof membrane penetration flashings and/or exterior roof membrane flashings, as well as pitch pan filler, can be expected, along with large splits or tears. Flashings may pull as the single-ply membrane swells and constricts with weather changes. “Most membranes like TPO and PVC have a little bit of flexibility. If it’s a metal, then you have expansion and contraction issues. It can affect the metal splitting, breaking, breaking a seal or connection, and even breaking fasteners,” Edie explains.
Wind, rain, and hail. Spring and summer storms can deliver a real lashing to your roof. High winds can dislodge equipment and send it and tree limbs tumbling over the roof, leaving a path of damaging membrane punctures across the field of the roof and flashings, even lifting or dislodging flashing. Hail can impact the flashing’s integrity and compromise the waterproofing ability of seams. Heavy rains or prolonged periods can degrade sealants over time.
What Are the Consequences of Weather-Related Damage?
“Leaks,” says Edie, when asked about why this damage is so concerning. If the adhesive has failed, fasteners are loose or missing, and the membrane no longer appears attached, rain can enter your facility. And if air can enter under the membrane, wind uplift is possible. During tropical storms, tornadoes, and straight-line wind events, there is a risk that the entire roof, including the roof deck, could blow off.
What Can You Do to Prevent These Leaks?
“Preventive maintenance is a good start,” suggests Edie. Regular inspections and an ongoing program of repairs and maintenance will catch problems when they’re small. Hiring a roofing contractor to perform general preventive maintenance ensures that the condition of caulking and sealants for counter flashings and terminations are checked regularly and replaced or sealed if necessary. General preventive roof maintenance will identify and repair items that need regular attention, such as:
- Terminations like pitch pans, that need resealing.
- Deteriorated caulking and sealants.
- Failing adhesive on open sheet metal seams.
As your roof and its sealants, caulking, adhesives, and flashings age, plan for more frequent inspections and maintenance.
Contact D. C. Taylor Co. today at 319.731.4118 or [email protected] to schedule general preventive maintenance.