- Not saying a nail-over is always a bad move. In some cases, it’s actually a decent option—especially if the first layer is still solid and you’re not dealing with a ton of valleys or weird roof angles.
- Midwest weather’s rough, but I’ve seen plenty of double-layer roofs hold up fine for 10+ years, as long as the decking underneath is dry and flat. The key is making sure you really check for soft spots, especially around chimneys, vents, and eaves. Sometimes folks skip that step and regret it later.
- Full tear-off does give you peace of mind, no doubt. But it’s not always in the budget, and sometimes insurance won’t cover it unless there’s visible storm damage. Had a neighbor who did a nail-over after hail—saved a chunk of change, and it’s been leak-free for five years now. He did get up in the attic and poke around first, though.
- One thing to watch: adding a second layer adds weight. Most houses can handle it, but if you’ve got an older structure or a low slope, it’s worth double-checking. I’ve seen sagging rafters from too many layers.
- Mold’s a dealbreaker, for sure. If you spot any, tear-off’s the only way. But if it’s just old shingles and the deck’s solid, sometimes a second layer buys you time to save up for a full replacement down the road.
- Personally, I lean toward tear-off when possible, but I get why folks go the other way. It’s all about what you find once you start poking around under those shingles. Sometimes you get lucky, sometimes you don’t...
I get the logic behind saving money with a nail-over, but I’ve got to push back a bit on the “10+ years” thing.
Maybe that’s true in some spots, but in my case (older house, lots of shade), the second layer trapped more heat and moisture than I expected. Ended up with curling shingles after about six years. If you’re not planning to stay long-term, maybe it’s worth the risk, but I’d say really weigh how much you’re actually saving versus possibly having to redo it sooner than planned.“I’ve seen plenty of double-layer roofs hold up fine for 10+ years, as long as the decking underneath is dry and flat.”
I get where you’re coming from—shade and older houses can definitely change the equation. I’ve seen a few roofs in my area (Midwest, lots of trees, humid summers) where the double-layer thing didn’t pan out as planned. The extra layer just seemed to hold onto moisture, especially after a big storm or two, and then you get that curling or even some moss creeping in. Not fun.
But I’ve also seen the flip side. My neighbor did a nail-over about 12 years ago on a ‘90s ranch, and it’s still holding up fine. His place gets a ton of sun and has good airflow, though. I think that’s the kicker—ventilation and how much shade you’ve got really make a difference. If your attic’s not breathing well, or if you’re in a spot that stays damp, that second layer can be asking for trouble.
Honestly, I’m not a huge fan of nail-overs unless the roof is pretty young and everything underneath is bone dry. Once you start layering over old decking or questionable shingles, it feels like you’re just hiding problems instead of fixing them. Plus, if you ever do get storm damage (hail, wind, whatever), insurance can get weird about double layers. Had a client last year who had to pay more out of pocket because their adjuster said the second layer made repairs trickier.
I get why folks do it—money’s tight and tearing off is a pain—but sometimes it’s just kicking the can down the road. If you’re planning to stick around for a while, I’d lean toward full tear-off unless your situation is really ideal for a nail-over. Just my two cents from seeing both sides... roofs are never as simple as they seem on paper.
If your attic’s not breathing well, or if you’re in a spot that stays damp, that second layer can be asking for trouble.
Couldn’t agree more. I’ve pulled up double layers where the bottom shingles were basically mush from trapped moisture—especially on low-pitch roofs with lots of shade. On the other hand, if you’ve got solid decking and good venting, sometimes a nail-over buys you a few years. Still, I always wonder what’s hiding underneath... tough call unless you know the roof’s history.
Still, I always wonder what’s hiding underneath... tough call unless you know the roof’s history.
That’s the part that gets me every time. I’ve seen “nail-over” jobs where the old shingles looked fine from the attic, but once we peeled them back, there was black mold and rotten decking—especially on north-facing slopes with heavy tree cover. Even with good venting, if the first layer was already compromised, you’re just sealing in the problem. I get the appeal of saving money and time, but for me, peace of mind usually wins out.