if leaks keep coming back or I see soft spots, that’s when I call a pro. Had a “quick fix” turn into a full deck replacement once... learned my lesson the hard way.
I can relate to that. Tried chasing leaks on my old flat roof for months—patch here, patch there, but water still found its way in. I was tempted to try flood testing too, but honestly, with older decking, it just felt like asking for trouble. Water has a sneaky way of finding the tiniest gaps and then you’re dealing with soggy insulation or worse.
What helped me was working methodically: start by checking all the seams and flashing after a rain (or even with a hose, but just a little at a time). Sometimes it’s not even the roof itself—could be around vents or where the roof meets the wall. If you’re seeing soft spots or sagging, though, I’d agree with calling in someone who can look underneath without making things worse.
It’s tough to know when to stop DIY-ing and bring in help, but peace of mind is worth something. At least then you know what you’re dealing with before it turns into a bigger headache.
- Seen this a lot: folks patching the same spot over and over, thinking it’s “fixed” until the next rain. It’s almost never just one spot.
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Couldn’t agree more. Flood testing sounds good in theory but on old wood? That’s how you end up with a ceiling collapse or hidden rot you can’t see until it’s too late.“I was tempted to try flood testing too, but honestly, with older decking, it just felt like asking for trouble.”
- Had a customer once who kept slapping tar on every seam. By the time I got called, water had already traveled sideways and soaked the insulation two rooms over. Flat roofs love to hide leaks—water will chase the path of least resistance every time.
- My rule: if you’re seeing soft spots or bubbling, stop with the patches. At that point, you probably need to open up a section and see what’s going on underneath. You might get lucky and find a small area, but usually if there’s softness it’s spread further than you think.
- Quick fixes are fine for emergencies, but for recurring leaks? Sometimes you just have to bite the bullet and get someone to pull things apart properly. Otherwise you’re just buying time—and sometimes not much of it.
I get where you’re coming from about not flood testing old decking, but honestly, I did it once on a 30-year-old roof and it actually helped me pinpoint a leak I’d been chasing for months. Yeah, you’ve gotta be careful—don’t go dumping buckets of water—but a slow hose and watching from below worked for me. Sometimes opening up the roof just isn’t in the budget right away, so I’d rather risk a little controlled water than keep guessing. Just my two cents—sometimes the “risky” move pays off if you’re careful.
I hear you on the “risky” move sometimes being the only move you can afford. I’ve been in that spot—old flat roof, mystery leak, and no way to just rip everything up and start over. I did the slow-hose trick too, but I’ll admit I was sweating bullets the whole time, hoping I wasn’t making things worse. For me, it actually worked out. Found a tiny split right at a seam that I never would’ve spotted otherwise.
One thing I’d add: if you’re going to try this, go super slow and have someone inside watching for drips. I started at the lowest point and worked my way up in sections, just a few minutes at a time. That way, if water started coming through, I knew exactly where to look. It’s not foolproof, but sometimes you’ve gotta work with what you’ve got.
Honestly, sometimes being careful and methodical with a “risky” method is better than just guessing and patching random spots. You’re not alone in taking that route.
That slow-hose method is honestly underrated. I’ve used it a bunch of times on older flat roofs, especially when the budget just isn’t there for a full tear-off. Did you notice if the split you found was right at a seam or more in the field? Sometimes seams are the sneakiest culprits, but I’ve also seen pinholes show up in the weirdest spots. Ever try using a dye in the water to help trace things? It’s a bit messy but can make tracking leaks inside way easier.
