Commercial and flat roofing in Fort Wayne

TPO, EPDM or modified bitumen

Most flat roofs in the Fort Wayne area use one of three membranes. Each handles a hot August and a frozen January differently.

Membrane	What it is	Where you see it
TPO	A white single-ply sheet whose seams are welded together with hot air	Newer stores, offices and warehouses; the white surface stays cooler in summer
EPDM	Black synthetic rubber, glued down or held with ballast, seams taped	Older commercial buildings, churches and schools
Modified bitumen	Asphalt rolls reinforced with fabric, torched, mopped or self-adhered	Porch roofs, home additions and small commercial buildings

Water that won't drain

A flat roof isn't completely flat. It needs enough pitch to move water to the drains or edges, and roofers call water that's still sitting there 48 hours after the rain "ponding." Ponds add weight, wear the membrane faster and, in a Fort Wayne winter, freeze and thaw over and over in the same spot. On a replacement we fix ponding with tapered insulation boards that build slope toward the drains.

Coat, repair or replace?

A coating goes over the old membrane as a new waterproof layer, and it only makes sense when the membrane is sound and the insulation under it is dry. So before we price a coating, we cut a small core out of the roof to see what's underneath. If the insulation is wet, a coating just seals the water in, and the roof needs a tear-off.

• Coat it: the membrane is aging but intact, and the core cut comes up dry.
• Repair it: a few seams or flashings have failed, and the rest of the roof is sound.
• Replace it: wet insulation, ponding that never goes away, or leaks in many places.

What commercial and flat roofing costs in Fort Wayne

A full commercial roof replacement typically costs $5 to $14 a square foot installed, based on national figures. Smaller jobs and partial work come in far lower, and coatings on small roofs average about $1,475.

Job	Typical cost
Full replacement, per square foot	$5 to $14
2,500 sq ft building	$12,500 to $35,000
10,000 sq ft building	$50,000 to $140,000
Roof coating on a small roof	$543 to $2,527
Flat roof repair	About $400 on average

The membrane you pick, how much wet insulation comes off, and the number of drains, curbs and rooftop units set the price. We price each of those on its own line.

Low-slope roofs on houses

Shingles need pitch to shed water. Indiana's code doesn't allow asphalt shingles on a roof flatter than 2 inches of rise per foot, so the back porch, the 1970s addition or the flat garage roof needs a membrane instead. Modified bitumen or a small EPDM or TPO roof is usually the right fit, and it ties into the shingles where the two roofs meet.

Commercial and flat roof questions