Otherwise, you risk missing stuff that ends up costing more down the line.
That’s interesting—especially about the hidden rot. I get what you mean about humid climates making things riskier. But do you ever run into homeowners who just can’t swing the cost of a full tear-off? I’m curious if there’s ever a situation where adding a layer actually worked out okay, or does it always end up biting you later? Sometimes I wonder if the risk is the same with newer roofs or if age really makes that much difference.
I’m right there with you on the budget side—when we got quotes for a full tear-off, I nearly fainted. Ended up going with a second layer on our old asphalt shingles because the inspector said the decking looked okay (as far as he could tell, anyway). It’s been five years and so far, no leaks or weird smells… but I do worry about what’s lurking underneath. Not sure I’d risk it if the roof was already sagging or if we lived somewhere super humid. Age definitely seems to matter—a newer roof under there might buy you some time, but if it’s ancient, I’d be nervous.
Not sure I’d risk it if the roof was already sagging or if we lived somewhere super humid.
That’s a good point—humidity changes everything. Ever had any storms since you added that second layer? I always wonder if heavy wind or hail would make hidden problems show up faster with two layers instead of one.
I always wonder if heavy wind or hail would make hidden problems show up faster with two layers instead of one.
That’s definitely something I’ve noticed in a few properties. We had a duplex with two layers—first big storm after the new layer went on, some shingles peeled right off. Turned out the old layer underneath was trapping moisture, so the new one just didn’t grip as well. In humid climates especially, that “sandwich” effect can cause rot or mold you won’t see until it’s too late. Single layer’s more work upfront, but less mystery down the line.
- Totally get what you mean about the “sandwich” effect.
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“the old layer underneath was trapping moisture, so the new one just didn’t grip as well.”
- Seen similar on a few buildings—looked fine until a big windstorm, then trouble.
- It’s tempting to just add a layer and save money, but hidden stuff (like rot or soft spots) can get worse fast.
- Full tear-off is a pain upfront, but at least you know what you’re working with.
- Not saying double-layer never works, but I’d rather deal with known issues than surprises down the road.