Roof Coatings in Madison, WI

A coating is not a patch for a roof that is failing underneath. We start every repair by finding where water gets in: open seams on a flat roof, backed-out fasteners on metal, split flashing at curbs and walls. Those get cut out and rebuilt first. Then we embed polyester fabric in base coat over seams and penetrations and let it cure. Wet insulation gets replaced, because coating over it seals the water in.

Before any coating goes down, we walk the whole roof and pull core samples. A core tells us what the membrane is, how many layers sit beneath it, and whether the insulation is dry. We probe seams, measure flashing heights, mark where water ponds, and run an adhesion pull test with the product we plan to use. The median home here was built in 1979, so we look closely for older repairs and extra layers.

Sometimes the core tells us coating is the wrong call. Saturated insulation across much of the deck, a membrane that has shrunk away from its edges, or structural sag in the deck all point to a tear-off. We say so plainly. When the roof is sound, a coating restores it in place, with no tear-off and no disruption to the building below. Replacement makes sense only when nothing sound is left to coat.

Installation begins with a clean surface: power washing, then primer where the substrate needs it (rust inhibitor on metal, a bleed-blocking primer on asphalt). Seams and penetrations get fabric-reinforced base coat. The field coat goes on in passes to a set dry film thickness, checked with a mil gauge as we work. Silicone holds up to ponding water on flat roofs. Acrylic suits sloped metal. With about 32 inches of rain a year, we plan around cure time.

A coating only works over a roof that is dry and sound, so the inspection decides whether coating is the right call at all. We walk the whole surface, probe seams and flashing, and look for ponding, blisters and split laps. Core cuts or a moisture meter show whether the insulation underneath is wet. If a large share of the roof is saturated, we say so and talk about replacement instead.

The estimate spells out what we found and what we plan to do about it. It names the coating (silicone, acrylic or urethane), the specified dry-film thickness, where reinforcing fabric goes, and how much wet insulation comes out. Commercial roof coating services vary widely from one contractor to the next. Having the scope in writing lets you compare bids line for line instead of guessing what each one covers.

Most coating jobs leave the existing membrane in place, which is much of the point. What comes off is anything that would fail under the new coat: wet insulation, blistered or delaminated patches, loose gravel, old tar repairs and chalky residue from aged coatings. Wet sections are cut out and replaced with new board so no water stays trapped under the finished surface. Then the roof is power washed and left to dry.

Once a wet area is opened up, the deck underneath is in plain view. Rusted steel deck gets wire brushed and primed, or cut out and plated where it has lost strength. Soft plywood or plank decking is replaced to match. A weak deck should not go into another winter carrying Madison's 36 inches of snow, so we fix it now. Low spots that hold water get built up, since ponding shortens the life of most coatings.

On a coating job, the underlayment is the base layer the finish coat bonds to. That means an adhesion primer over EPDM, a bleed-blocking primer over asphalt or modified bitumen, or a rust-inhibiting primer on metal roofs. Seams, fasteners, penetrations and flashing get a base coat with polyester reinforcing fabric embedded in it. Skip that fabric at the laps and a coated roof tends to split open again along the same lines.

The field coat goes on by spray rig or heavy-nap roller, with a second pass laid crosswise to the first so thin spots do not line up. We check wet-film thickness with a notched gauge as we go, because coverage that looks even can fall well short of spec. Weather sets the pace. Coatings need a dry surface, dry hours ahead and temperatures inside the manufacturer's range before we open a pail.

Before we call a roof finished, we walk it again with the estimate in hand. Cured film is checked for thickness at sample points, and we look for pinholes, bare fasteners, missed laps and fabric edges that did not fully wet out. Drains and scuppers are flood-tested where the roof allows it. Anything short of spec gets another coat. The readings and photos go to you, so the record stays with the building.

Coating jobs are cleaner than tear-offs, but they still leave debris: cut-out insulation, old flashing, fabric scraps, empty pails and masking plastic. All of it comes off the roof and leaves the property with us. We pull tape from rooftop units, walls and windows, clear the drains, and walk the ground around the building for stray fasteners and scrap. Where a building stays open during work, entrances are kept clear every day.