Reflective Seamless Membranes For Arizona Roofs & Tanks

On a dark aged modified-bitumen or single-ply roof in Phoenix, mid-afternoon surface temperature routinely runs 160 to 180°F in July. A clean, high-reflectance white membrane typically reads 40 to 70°F cooler at the same moment on the same roof. That is a measured surface delta, not an energy guarantee — how much of it reaches your utility bill depends on your insulation, your deck type and how much of your conditioned load is actually roof-driven. Buildings with thin or wet insulation and roof-mounted ductwork see the biggest change.

It will waterproof through it, but it will not remove it. Ponding is a slope and drainage problem, and no membrane cures bad fall. What we can do is specify a chemistry that tolerates permanent immersion — some silicone and polyurea systems handle standing water indefinitely while most acrylics soften and re-emulsify in it — and, where the pond is caused by a low spot rather than a deck deflection, build a tapered fill to restore fall toward the drain. If the ponding comes from a structural sag or an undersized drain, we will tell you that before quoting a membrane over it.

It comes down to how the polymer backbone reacts to ultraviolet light. Aromatic polyurea is tougher per dollar and builds thickness fast, but UV breaks down its aromatic rings, so it ambers and then chalks — a powdery surface layer that washes off in the monsoon and slowly thins the membrane. Aliphatic chemistry has no aromatic ring to attack, so it holds color and gloss for years under direct sun. The right answer on a roof is usually both: an aromatic base coat for build and elongation, protected by an aliphatic or silicone topcoat that takes the UV load. Chalking on a bare aromatic roof is not a defect; it is the material doing exactly what its chemistry says it will do.

Most sound roofs can be recoated, and that is the main economic argument for this work — a restoration keeps the existing assembly, the insulation and the tear-off cost out of the project, and it keeps thousands of square feet of roofing out of a landfill. What it requires is verification: core samples to confirm the insulation is dry, adhesion pull tests on the existing surface, and infrared or moisture scanning across the field. Wet insulation must be cut out and replaced regardless. A membrane installed over saturated insulation traps the water and the roof fails from underneath.

That is where roofs leak, so that is where the labor goes. Every curb, drain, vent stack, conduit penetration, skylight and equipment leg gets a reinforced detail — polyester fabric embedded in the base coat and wrapped up the vertical before the field membrane goes on. Parapet walls are coated continuously from the field, up the wall and over the top of the cap, so there is no termination sitting in the horizontal water path. A seamless membrane is only seamless if the details are done first; spraying the open field is the easy part of the day.

Yes, and it is closely related work. Water storage tanks, process vessels, fuel and chemical tanks across Arizona take the same UV and thermal load as a roof, plus a vertical geometry that punishes any coating that sags during application. Fast-gel plural-component polyurea is well suited to that — it sets before it can run, so it builds full thickness on a vertical shell in one pass. Exterior tank work pairs naturally with the containment lining underneath it, so we frequently scope the shell exterior and the berm together.