KEE is the answer to a narrow question: what do you put on a roof that is going to be soaked in something nasty every week? It is a PVC-alloy membrane, welded like PVC and built to keep its flexibility as it ages. If the roof does not see grease, oil or chemical exhaust, KEE is more membrane than the job needs and we will say so. If it does, KEE can be the cheapest roof on a twenty-year basis.
In Coeur d'Alene, ID the same roof also has to carry 60 psf of design snow. The chemistry and the snow are separate lines in our bid, so you can see what each one costs.
The Call: KEE, PVC or Something Else
KEE sits above standard PVC in resistance and in price. PVC resists fats and many chemicals, and for most restaurant and clinic roofs it is enough. KEE earns its keep where the exposure is heavier or more varied: long-running kitchen exhaust, process vents, laboratory discharge or a mix nobody can list with confidence. It also suits roofs where the owner wants the longest possible service life and will pay for it.
The call against KEE is just as clear. On a plain warehouse roof with a few units, a welded TPO does the job for less. On a roof with extreme chemical exposure, a coating or a different system may be the better answer. We show KEE as an alternate beside PVC and TPO, with prices, and the owner picks.
Tenant mix can shift the answer too. A roof over a single owner-occupied building can be specified to that owner's exhaust. A roof over a multi-tenant building has to allow for whatever the next tenant brings, and that uncertainty is a point in KEE's favor.
What Makes It Different: A Plasticizer That Stays Put
Standard PVC membranes use plasticizers to stay flexible, and over time some plasticizer can leach out, especially under heat and chemical exposure. The sheet then stiffens and shrinks. KEE membranes use a ketone ethylene ester that is designed to stay in the sheet, which preserves flexibility and slows that aging. The seams are hot-air welded into one continuous membrane, and the reinforcing scrim gives it strength.
This matters on roofs that run hot. A black rooftop duct, a hot exhaust plume or a mechanical room curb can heat the surface well above air temperature, and a sheet that holds its flexibility there lasts longer. Cold flexibility helps too. Coeur d'Alene has logged minus 30 F, and a membrane that stays supple through that kind of night is less likely to crack at a fold.
Fire performance is a second reason owners ask about it. KEE and PVC membranes carry inherent flame-retardant properties, which matters on a roof with hot work, kitchen exhaust or electrical gear. We confirm the roof assembly's fire rating against the plans before we order material, because the rating belongs to the whole assembly, not to the sheet alone.
What It Costs: A Premium You Should Be Able to Justify
KEE costs more per square foot than TPO and more than standard PVC. Prefabricated corners and boots, which are often used, add to the material line and cut field labor. Insulation, cover board, fastening and edge metal cost the same as under any single-ply. We show five lines: membrane, details, insulation and board, edge metal and drains, with tear-off separate.
The way to test the premium is to count the years. If the roof is going to see grease or chemicals, and a cheaper membrane would need replacing early, KEE's higher first cost spreads over a longer life. If the exposure is light, the math goes the other way. We lay both numbers side by side. A replacement scope with a KEE alternate lets the owner make that call from the bid.
Where It Fails First: Details, Drains and Mechanical Damage
KEE does not fail from chemistry as often as lesser sheets. It fails where any single-ply fails: at the details, at the drains and where something sharp meets the surface. Corners and pipe boots are the first place a bad weld shows. A drain sump set high leaves a pond, and a pond sits on the sheet through the freeze. Foot traffic around exhaust fans wears the surface, and a dropped tool can cut it.
We reduce those risks by planning the details, setting drains low, and adding walkway pads to the service routes. A roof that sees weekly maintenance visits needs a protected path to every unit. We put the pads on the plan, price them as a line item and note their location in the record. A quarterly look at the pads and the grease areas is the cheapest insurance on a KEE roof, and our preventive maintenance visits cover it.
Where It Fits: Kitchens, Clinics and Plants
Post Falls has several kinds of building worth a KEE look. Healthcare employers such as Pleasant View Surgery Center, the Rehabilitation Hospital of the Northwest and North Idaho Day Surgery each employ between 200 and 299 people, and clinical buildings carry exhaust and mechanical equipment on their roofs. Employers there such as Buck Knives and Tedder Industries run buildings whose rooftop exhaust we would want to see before specifying a membrane.
Across the Rathdrum Prairie, in Post Falls, Hayden and Coeur d'Alene proper, food service, labs and light manufacturing are the kinds of buildings where a chemical-resistant roof is worth pricing. For each, we ask for the exhaust list before the bid.
Snow, Wind and Ice: The Same Details Apply
A KEE roof carries the same snow as any other roof. The city's 60 psf snow load and severe weathering rating apply to a KEE roof exactly as they do to any other. Drift pockets behind parapets and rooftop units, drains that stay clear in January and edge metal that holds in a windstorm decide whether the roof lasts, whatever the membrane is made.
We detail the perimeter heavier than the minimum, because a windstorm like the one in November 2015 goes straight for the edges. Welds are probed after they cool, and test welds are cut and pulled at the start of each shift, particularly on cold mornings.
Schedule: Order Details Early, Weld in the Warm Months
Prefabricated details are ordered after we measure the roof, not from the drawings. A wrong boot size is a week lost. Installation follows the usual single-ply window, spring thaw to first hard freeze, with winter work only when a failing roof leaves no choice. Closeout includes the walk with the GC, photographs of every detail and the maker's warranty documents. For existing roofs, a moisture survey tells us whether a recover is an option or a tear-off is required.
One more habit separates a clean job from a callback. Before the membrane goes down, we check the substrate for moisture and the deck for fastener back-out, and we hold the start until both pass. A KEE sheet laid over a wet board or a loose deck inherits the problem, and the warranty will not fix it. That hold point costs a morning and removes the most common cause of early failures.
Commercial Roofing Questions
Is KEE better than PVC?
On heavy exposure, yes. On ordinary roofs, PVC or TPO is enough. We price them side by side.
What does KEE cost compared with TPO?
More per square foot. We show the difference as an alternate so the owner can weigh it against the roof's exposure.
Can KEE go over an old roof?
If the old roof is dry and sound, a separation layer may be needed. We scan and core before we decide.
Does KEE need special welding?
It welds with hot air like PVC. Heat and speed need adjusting to the day. We test-weld every shift.
What if we are not sure what the exhaust contains?
Send us the equipment list and the maintenance schedule. If it is still unclear, we price the roof in KEE and in a standard alternate and note the exposure risk.