Restaurant & Retail Roofing in Troy, MI

The mechanical code sets the hardware. A grease duct serving a Type I kitchen hood that ends above the roof must discharge at least 40 inches above the roof surface. The exhaust fan has to be positioned so its discharge doesn't hit the roof, and a vertical-discharge fan needs a drain at the bottom of its housing that empties into a grease reservoir. Upblast fans must be hinged so they can be tipped for cleaning, with the duct rising at least 18 inches above the roof. In practice, grease still escapes when reservoirs overflow, filters are skipped or the fan is cleaned on the roof.

The membrane decides how much that grease costs you. The federal guide specification for EPDM roofs says not to use EPDM next to kitchen exhaust discharge, because grease and oil attack it, and one EPDM maker tells installers to keep greases, vegetable oils and animal fats off its sheet. Makers market PVC, and PVC blended with KEE, for food-service roofs. In one maker's 30-day lard immersion test, its standard PVC lost 21 percent of its weight and its PVC KEE lost 12 percent, a lab result the maker itself says does not represent real-world exposure.

Two PVC makers' food-service brochures also say their warranties do not cover grease exposure. A grease-resistant membrane narrows the risk; a containment unit, a sacrificial pad and regular fan cleaning keep grease off the roof in the first place. The membrane itself is covered on PVC roofing.

Grease damage usually shows up on a roof walk. The membrane around the fan curb discolors, and where grease has been attacking it the sheet can feel soft or look swollen next to clean membrane a few feet away. Grease also runs with rainwater toward the nearest drain, so the damage often trails away from the fan in a stripe. If you see that pattern, have the fan and its reservoir checked before the roof is patched, or the patch will fail the same way.

A strip center often runs one continuous low-slope roof over five or ten tenants, each with its own rooftop unit, vents and maybe a kitchen fan. Leaks get patched tenant by tenant, so over the years the roof becomes a quilt of repairs in different materials. Before replacing, sort out who pays: leases differ on how roof repair and replacement are split between landlord and tenant, and a restaurant tenant's grease damage may fall under a separate clause. A single scope for the whole building, with per-unit breakouts, makes those conversations easier.

Front parapets on retail buildings carry sign raceways, lighting and bracket bolts driven through the coping and the wall. Each fastener is a leak path into the wall, and the water often shows up inside the storefront, not on the roof. Canopies and awnings over entries add their own small roofs and their own wind exposure: on June 5, 2024, storm reports logged a gas station canopy collapsing onto cars near Farmington in Oakland County. Coping and parapet details are covered on roof flashing repair.

Restaurants and grocery tenants put walk-in cooler and freezer condensing units on the roof, with refrigerant lines dropping through pipe boots or pitch pans and condensate draining onto the membrane. Service techs walk the same path every visit. In winter that condensate can freeze into a sheet of ice right on the service path, since Detroit's normal lows sit below freezing from December through March. Ask for condensate piped to a drain, equipment on rails high enough to reflash under, line sets through proper boots rather than sealant-filled pans, and walkway pads to each unit.