07/17/2026
The $20 can of roof tar that could cost you $50,000. 🪣🛠️
It happens all the time across Fort Myers, Cape Coral, and Naples: a maintenance guy spots a small drip on a flat roof seam, buys a bucket of black mastic (tar) from a local supply shop, and smears a thick layer over the crack. The leak stops for a few days, and everyone thinks the problem is solved.
But in Southwest Florida, a mastic patch is a dangerous illusion.
Here is why the "Mastic Band-Aid" trap is so destructive to commercial buildings:
1️⃣ It doesn't stretch: Under our intense summer sun, flat roof membranes expand and contract constantly. Mastic quickly bakes, hardens, and cracks right open again within a few weeks.
2️⃣ It traps rot: Applying tar over a leak creates a non-breathable seal that traps existing moisture inside the roof insulation.
When the hot sun beats down, it literally bakes that trapped moisture—turning your solid structural wood decking into wet, rotted mulch and creating a silent breeding ground for mold.
At PRG Roofing, Randy and Rob don't believe in band-aids. We conduct actual moisture-detection tests to ensure the wood underneath is healthy, and we use permanently flexible, engineered materials that last.
We just published a full, unfiltered article explaining why patching flat roofs with tar is ruining local commercial substructures—and how to fix leaks permanently.
Read the full breakdown before your maintenance team reaches for the mastic:
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🔗 Read the Full Article: https://cityscoop.us/fortmyersfl-roofingcompany/2026/07/14/is-a-mastic-repair-valid-why-patching-flat-roofs-with-tar-can-ruin-substructure/