At Vista Towers on Monkey Island, Ridgeline Roofing & Solar recently inspected the 12th-story rooftop of this high-rise overlooking the lake and discovered exactly why commercial roofs must be properly prepped and fully removed before reinstallation.

The current TPO roofing system is failing, and the cause is clear: trapped water under the membrane, lingering for years, has led to deep-seated moisture intrusion and ongoing leaks around critical drainage areas.

Why This Roof is Failing

This roof sits above the elevator motor room—making it the highest point of the structure and one of the most vulnerable to long-term weathering. During inspection, Ridgeline identified the following:

• Trapped water beneath the TPO, confirmed by high moisture readings
• Persistent leaking at the roof drain, the central low point in this “cereal bowl” shaped layout
• Underlying modified bitumen and gravel signs the roof was never fully torn off in the previous installation
• Expensive logistics: A 12-story chute was likely avoided in prior work, resulting in compromised layering

“When we cored this roof, we found layers of old mod-bit and gravel. That’s a red flag. Instead of removing the old system, they built over it, trapping moisture and creating bigger problems down the line,” said Tim Yates.

What Happens When You Don’t Tear Off

Flat roofs need a dry, stable foundation for any new membrane. When old roofing layers—especially gravel and mod-bit—are left in place under new TPO, water gets trapped between them. This leads to:

• Mold and insulation decay
• Drain failure and pooling
• Leaks that spread far beyond the entry point
• Premature failure of the new roofing system

At Vista Towers, water has wicked out well beyond the drain area, soaking into insulation across the rooftop.

What Comes Next

Ridgeline Roofing & Solar is now preparing a full tear-off and replacement estimate, complete with moisture barrier protection, new tapered ISO insulation, and a warrantied TPO membrane installed to spec.

For buildings like Vista Towers—especially with complex logistics—doing it right the first time isn’t just smart. It’s necessary.

Is your roof holding hidden water? Let’s find out. Contact us today!

Hear Tim’s Thoughts

Video Transcript: "Hey, Tim Yates, Ridgeline Roofing and Solar.
We're here at Shangri-La Vista Towers.
And I'm with Jerry, Phillip, and Dave.
And we are checking some roof out.
This is the, is this a 12-story, Jerry?
This would be the 12th story on this building.
And the reason why most of these high-rises have an additional story like this is for the elevator motors.
They kind of got to be above everything else.
So this is about a 20-square piece.
It's TPO.
It's holding a lot of water.
They're seeing water come in around this drain.
And the whole thing's set up kind of like a cereal bowl.
So it all comes towards this drain.
And the water has been so bad coming in that it's, we're getting moisture readings all the way out here.
So we went ahead and cored it.
Here's our core over here.
It's our coring tool.
Cored it.
And to our surprise, this has a lot of modifying underneath it, which is not good.
And then it also had a lot of gravel.
So I can see why they didn't take this roof down all the way last time.
Because when you get a chute that goes 12 stories in the air, it gets expensive.
So here's what she looks like all the way down.
Not so much fun, but it sure is beautiful out here.
We were seeing some bass boats flying by earlier.
And we got a little jealous.
So this is going to have to be replaced.
We're going to put an estimate in on it and see what happens.
So if you've got any questions about your roof, residential or commercial, please give us a call."