The Drip Is Rarely Under The Hole

Following Water Backward Across A Flat Deck

Most calls start with a location. The drip is over aisle six, or by the dock door, or above the office in the corner. That location is useful, because it tells us where the water finished its trip. It almost never tells us where the trip began.

A commercial low-slope roof is one continuous waterproof sheet laid over insulation and a structural deck. When a seal fails somewhere in that sheet, water gets underneath and travels along the deck, following whatever slight fall the building has, until it finds a gap it can drop through: a fastener hole, a joint between deck panels, a conduit chase. That first gap can be fifty feet from the actual breach.

So answering where the leak is starts on the roof, with the whole drainage pattern in view. Setting a ladder under the stain comes later, if at all.

Why Sealing Above The Drip Keeps Failing

A crew that climbs up directly over the wet spot and smears sealant on whatever looks suspicious has a decent chance of sealing nothing that was actually leaking. The weather turns dry for a week, the ceiling stops dripping, and everyone assumes it worked. The next real storm sends water through the exact same opening, because the breach upstream never got touched.

The cost of that miss is mostly hidden. Water that keeps entering upstream soaks the insulation between the breach and the drip, and wet insulation stays wet, gets heavy and stops insulating. Every week spent chasing the wrong spot widens the wet area.

Inside clues still help when they are used correctly. A drip that starts minutes into a rain is usually near its entry. One that shows up hours later has traveled. A leak that only appears with wind from one direction points at the side of the building facing it. We ask about all of that before anybody climbs.

Details Get Checked Before The Field

The breach is almost always at a detail, because details are where someone cut the membrane and then sealed it back up by hand.

• Curbs under rooftop units. Flashing runs up the sides of the curb and has to stay sealed at the corners through years of heat, cold and vibration.
• Penetrations. Pipes, conduit and vents each come through the deck with a boot or collar, and every one of those seals ages on its own clock.
• Drain sumps. The membrane steps down into the drain bowl and gets clamped there. A loose clamp ring or a crack around the bowl turns the lowest point on the roof into the way in.
• Expansion joints. Long buildings need them so the structure can move, and the cover over the joint has to move along with it. When it cannot, it tears.
• Parapet flashing at the perimeter. The membrane turns up the wall and terminates under metal or coping. Water that slips behind that termination runs down inside the wall and appears somewhere nobody would think to blame the roof.

We work through those in order of suspicion, starting with whatever sits uphill of the drip along the fall of the deck, and we look over the stretch of roof between that detail and the stain on the way. A blister, a split or a soft area in that stretch earns a note even when it turns out to be a separate problem. Once the entry is confirmed, the repair goes on in the same material and method as the surrounding roof, so the fix ages at the same pace as everything next to it.

Product Underneath Changes The Order

A leak over an empty corner can wait for a dry day and a careful permanent repair. A leak over racked inventory, finished goods or a production line does not get to wait. When the building tells us product is under the water, the first job is an emergency patch that stops it, even if the permanent repair needs better weather or material that has to be ordered.

We are clear about which one you have. An emergency patch gets written down with where it went and what the permanent detail will be, so nobody in the building closes the ticket on a problem that is only contained.

Fifteen Minutes South, Straight Up Cicero

Our shop is in Alsip, fifteen minutes south of Bedford Park, and the drive is a straight shot up Cicero. A call at eight in the morning can put somebody on your roof before lunch. On a leak, that gap between the call and the climb is most of what matters, since every hour the water runs it is soaking something.

Being close also changes the follow-up. If a stain comes back after the next hard storm, we are near enough to go back up and look without it turning into a scheduling event for anybody. The patch either held and the inside dried out, or we keep looking.

The Owner Walks The Roof

Angelo Ristich runs the jobs himself. He took over the company from his father Frank, and the man you describe the leak to on the phone is the same one who goes up and traces it. On a tracing job that continuity is worth a lot, because the small details you mention, which rains, what time, how much, are exactly what narrow the search.

Leak work here is part of the same commercial roof leak repair we run across the south suburbs. Finished low-slope repairs are in the gallery. Photos of the stain and of the roof area above it tell us where to look first, and they can go through the contact page.