Flat and Foam Roofing
Flat roof and spray foam systems for residential and light commercial properties.
Kellum Roofing installs, replaces and recoats flat and low slope roofing systems across Glendale, Scottsdale, Phoenix and the surrounding Valley. Flat roofing is everywhere in this market, both on light commercial buildings and on the enormous number of Valley homes with a flat section, a patio cover, an addition or a full flat roof. It is also the roof type that gets neglected the longest, because nobody sees it from the street.
Why the Valley Has So Much Flat Roofing
Southwestern residential architecture in Arizona leans heavily on flat and low slope roofs. Territorial, pueblo, mid-century and contemporary desert homes all use them, and even conventional pitched homes here commonly have a flat section over a garage, an addition, a porch or a covered patio. That works well in a desert because there is not much annual rainfall to shed and no snow load at all. It works considerably less well for a few weeks a year when a monsoon dumps a large volume of water very quickly on a surface that is designed to drain slowly. A flat roof that has been ignored for a decade is fine three hundred and fifty days of the year and a serious problem on the other fifteen.
Spray Polyurethane Foam, and Why It Suits This Climate
Spray polyurethane foam is applied as a liquid that expands into a seamless insulating layer bonded directly to the roof deck. A protective elastomeric coating goes over the top of it. Seamless is the key word. A flat roof leaks at its seams and its penetrations, and foam does not have seams. It self-flashes around vents, pipes, curbs and parapet walls, which are exactly the places a seamed system fails. It also adds genuine insulation value, which on a flat roof over living space in a Phoenix summer is not a minor benefit. Foam can also be sprayed over some existing roof systems rather than requiring a full tear-off, and it can be built up to correct ponding areas by adding thickness where water sits. The tradeoff is that foam depends on its coating. The coating is what protects the foam from ultraviolet degradation, and it needs recoating periodically. A foam roof that is maintained on schedule can serve for a very long time.
Coatings and Recoating
If you have an existing foam roof in decent structural condition, a recoat is usually the most cost-effective thing you can do for it. We clean and prepare the surface, address any damaged foam, and apply a new elastomeric coating. It restores the ultraviolet protection, reflects heat, and resets the maintenance clock without the cost of a replacement. Reflectivity matters more here than most places. A bright reflective coating on a flat roof over conditioned space measurably reduces the heat load coming into the building. The catch is timing. Recoating works when the foam underneath is still sound. Once ultraviolet has degraded the foam itself and water has gotten into it, coating over the top just seals the water in. We will tell you honestly which situation you are in.
Ponding Water, Drainage and Scuppers
Standing water is the single most common issue we find on Valley flat roofs. A flat roof is never truly flat. It is built with a slight slope toward drains or scuppers, and over time settling, deck deflection or a poorly executed repair creates low spots where water collects and sits. Ponded water accelerates the breakdown of nearly every roofing material, adds significant weight, and finds any weakness in the membrane. Meanwhile the scuppers and drains that are supposed to move water off the roof fill with dust, gravel, palm debris and blown litter, which is a constant here. Part of what we do on a flat roof assessment is check whether water is actually leaving your roof. Sometimes the fix is a foam build-up to correct the slope. Sometimes it is clearing and reworking the drainage. Sometimes the scuppers were undersized from the beginning.
Commercial and Light Commercial Flat Roofs
The same systems apply to commercial buildings, and we handle office, retail and light industrial properties under commercial roofing. The considerations shift somewhat, since a commercial flat roof usually carries far more rooftop equipment, and every HVAC curb, conduit run and exhaust penetration is a potential leak point that needs proper detailing. Commercial owners also tend to care about disruption. Foam and coating work can generally be done without shutting down operations underneath.
Flat Roof Repair and Maintenance
Not every flat roof needs a new system. We handle targeted roof repair on flat sections, including membrane repairs, penetration reflashing, scupper and drain work, and emergency tarping during monsoon season. Flat roofs reward maintenance more than any other roof type. An annual look at the drains, the penetrations and the coating condition costs very little and catches the small problems while they are still small. It is the least glamorous advice in roofing and the most reliably correct.
What We Look At on a Flat Roof Inspection
We check the condition and thickness of the existing system, whether there is moisture trapped inside it, the state of the coating, every penetration and curb, the parapet walls and their caps, the flashings where the flat section meets an adjoining pitched roof, the drains and scuppers, and whether water is ponding and where. That last one often explains everything else. Then we tell you whether you are looking at a repair, a recoat, or a replacement, and we show you the photos that led us there.
Not sure what your roof needs?
Get a free inspection with photos from a licensed Glendale roofer. Call (480) 258-0925 or request an estimate online.
Free InspectionOther Services
We walk the roof, photograph what we find, and give you a written estimate, often the same day.
(480) 258-0925
Built to endure
Arizona heat.
BBB Accredited
Accredited Business since 2024.
Licensed, Bonded, Insured
Arizona ROC 352782, Specialty Dual.
Locally Owned
Based in Glendale. Not a franchise and not an out-of-state storm chaser.
Manufacturer Warranties
Underlayment warranties from 10 to 30 years.
Kellum roofing was great! They were professional, courteous and very punctual during my roof replacement. They were also very competitively priced. I highly recommend Jeremy and his team for any size job!