Deck-Armor’s a solid pick for underlayment, especially if you’re worried about breathability. I’ve seen it hold up in some tough spots, but honestly, it’s not a cure-all—if your ventilation isn’t dialed in, even the best materials will run into trouble over time. Ridge vents are a game changer, but with complex rooflines, sometimes you still get dead spots. I usually suggest running a smoke test before finalizing vent placement…sounds silly, but it can save you grief down the line. The upfront cost hurts, yeah, but fixing mold or rot later is way worse for the budget.
That’s spot on about ventilation being just as important as the underlayment. I went with Deck-Armor on a reroof about five years ago, and while it’s definitely more breathable than traditional felt, I noticed the attic still ran hot until I tweaked the venting. Ridge vents helped, but my roof’s got a couple valleys and dormers that made airflow tricky. Ended up adding a couple of low-profile intake vents near those dead zones—wasn’t cheap, but it finally balanced things out.
The smoke test is a great idea. I did something similar with incense sticks (my contractor thought I was nuts), but it actually showed where the air just wasn’t moving. Caught a couple spots we’d have missed otherwise.
If you’re budgeting for CertainTeed, don’t overlook flashing and ice/water shield either. Those add up fast, especially if you’re in a colder climate or have a lot of roof edges. I learned the hard way that skimping there just means more headaches later... It’s all about spending a little more upfront to avoid way bigger repair bills down the road.
- Ran into the same thing with attic heat, even after putting in a “breathable” underlayment (I used CertainTeed DiamondDeck). Ridge vent helped, but the real game changer was adding more soffit vents.
- My house is older, so the original builder barely put in any intake. Once I drilled a few more holes and added vent covers, temps dropped noticeably.
- Agree on not skimping on flashing—my first roof job I tried to save by reusing some old stuff. Ended up with leaks around the chimney two winters later. Had to pay for repairs and redo the flashing anyway.
- Ice/water shield is pricey, but in my area (upstate NY), it’s non-negotiable. Ice dams are brutal here.
- One thing I’d add: budget for extra nails and starter shingles. I underestimated both, and it meant an extra trip to the store mid-project.
- If you’re doing valleys, consider the “open metal valley” method. Costs a bit more, but I’ve had less trouble with debris and leaks since switching.
- All in, I’d say don’t cut corners on anything that keeps water out. The rest is mostly cosmetic.
Funny you mention the soffit vents—I've lost count of how many attic inspections I’ve done where folks swear they have “good ventilation,” but it’s all ridge vent and barely any intake. It’s like putting a straw in a bottle with the cap on… air’s not going anywhere. The difference after folks add more soffit vents is almost immediate, especially in these older places where insulation and airflow weren’t top priorities back when.
I’ll second the point about not reusing flashing. I had a seller last year who insisted the old stuff was “just fine” because it looked okay from the ground. Come first big rain, water was sneaking in behind the bricks. Ended up costing them more than a fresh piece of flashing would’ve—plus a chunk of drywall repair. Sometimes saving a couple bucks up front just isn’t worth the headache.
On ice/water shield, I’ve seen houses up here try to get away with the bare minimum and, sure enough, you see those telltale stains inside come spring. If you’re in upstate NY, I’d say don’t gamble with it. Same goes for starter shingles. I get why folks try to cut corners, but every “shortcut” seems to turn into a call-back or a repair bill down the line.
One thing I’m curious about—has anyone run into issues with CertainTeed’s DiamondDeck getting a little too slick during install? Had a crew complain about footing last year, but I haven’t seen it myself. Wondering if that’s just an installer gripe or an actual safety concern. Also, for folks who’ve done open metal valleys: do you notice much extra noise during rain? I’ve always wondered if that’s something homeowners regret after the fact, or if it’s just a non-issue once everything’s sealed up.
Curious what others have run into with these details. Sometimes it feels like every house has its own set of “gotchas” no matter how much you plan.
I’ve got a pretty old house (built in the 50s) and when we did our roof last year, I was surprised how much the venting stuff mattered. I always thought “a vent’s a vent,” but turns out, not so much. We had almost no soffit intake—just a ridge vent—and the attic was basically an oven. After adding more soffit vents, it actually felt cooler up there, which I didn’t expect to notice that fast.
About DiamondDeck being slick, my roofer mentioned it too. He said it was especially bad on a damp morning—almost like walking on ice. They ended up laying down some old mats for footing until things dried out. He didn’t seem mad about it, just said you have to be careful and maybe not rush if there’s dew.
On the open metal valleys, I was worried about rain noise too but honestly, I haven’t noticed anything inside. Maybe if you’re right under the valley in a quiet room you’d hear something, but with insulation and drywall, it’s not obvious. The bigger “gotcha” for us was how much flashing and underlayment add to the price, but skipping them just didn’t seem worth the risk.
