How Long Should a Roof Last in Pennsylvania?
Quick answer
Most shingle roofs in Pennsylvania last about 20 to 30 years. The home inspectors' association InterNACHI puts basic 3-tab shingles at about 20 years and architectural shingles at about 30, with metal at 40 to 80 and slate at 60 to 150. Storms, wind, and how well the roof was put on decide where yours actually lands.
I've been roofing around Washington County for about 10 years now, the last four running JS Jobs Roofing Plus on my own. Before that I spent almost 30 years in bars and restaurants, so I'm used to talking to people straight. When somebody asks me how long a roof should last, what they usually want to know is whether theirs is done.
The chart number is a starting point. What I look at is the roof itself: damaged areas, soft or rotted wood, and the spots that are going to cause trouble next. Here's how I'd think about it if it were my house.
How long each type of roof lasts
| Roof type | Expected life (InterNACHI) | What you'll see around here |
|---|---|---|
| 3-tab asphalt shingles | About 20 years | Flat, single-layer shingles on a lot of older roofs |
| Architectural asphalt shingles | About 30 years | What's on most houses now. I install Owens Corning Duration. |
| Metal | 40 to 80 years | Standing seam panels, plus metal shingles made to look like asphalt or slate |
| Slate | 60 to 150 years | Older homes. I've torn slate off and put shingles on when it was leaking. |
Source: InterNACHI's Standard Estimated Life Expectancy Chart for Homes. InterNACHI notes that severe weather can shorten any roof's life.
Why Pennsylvania roofs don't always reach the chart number
Those numbers assume the weather plays fair. Ours doesn't always. Storm season used to be in the spring, and now August has been crazy, with hurricane remnants coming up the East Coast. Most of the calls I get after a storm are the same: the wind blew shingles off and now there's a leak.
Winter matters too, but mostly for timing. December, January, February, and a good part of March, you're watching the weather, because shingles aren't supposed to go on below 45 degrees. A roof that's already failing in the fall has to make it through all of that before anybody can replace it.
What decides how long your roof lasts
- The material. A 3-tab roof and an architectural roof installed the same year won't wear out the same year. Metal and slate are in a different league.
- Storms and wind. Every storm that lifts or blows off shingles shortens the clock, especially on a roof that's already older.
- How it was installed. A lot of roof problems are installation problems. That's why every replacement I do comes with a 5-year workmanship warranty at no charge.
- What's under the shingles. Rotted decking can't hold nails the way good wood does. Nobody sees it until the old roof comes off.
- Upkeep. InterNACHI lists maintenance as one of the things that decides a roof's life. Catching a loose shingle or a small leak early keeps it from turning into rotted wood.
Two local roofs that show how this plays out
Monongahela: repairs until it made sense to replace
Jake's roof kept taking hits. Storms loosened shingles and blew some clean off, and he had leaks. We did repairs and gutter work to keep water out of the house, and when it was time, we replaced the whole roof.
“Joe has been fixing up my roof and gutters since I moved into my home, and has always provided quality work and quick service. He and his crew recently put a brand new roof on my home, and I was very pleased with their work. They arrived at dawn and worked the entire day, finishing up that same evening.”
Jake Gerba, Monongahela, PA · 5 stars on Google
Washington: a slate roof that didn't make it to 150
Slate is supposed to outlast all of us. AJ bought an older home in Washington with a slate roof that was leaking from storm damage. We took the slate off, checked the structure underneath, and put a new shingle roof on. Slate tear-offs make a real mess, so cleanup was a big part of this one.
“We have moved into an older home with a slate roof that needed to be replaced due to it leaking from storm damage. Transitioned it from slate to shingle. With the debris and dust related to removing a slate roof, Joe and his team did an incredible job cleaning up and practically removing all debris from around my home making it safe for my dogs and kids to be out there and play the day after it was complete.”
AJ Creamer, Washington, PA · 5 stars on Google
Repair or replace?
Here's how I handle it. I don't put a warranty on repairs, because most repairs are on older roofs, and you start guaranteeing things like that, you're going to find yourself in some trouble. What I do say is that if it's the same thing I came out for and it's still leaking, I'll come back out and not charge you double.
When the repairs start stacking up the way they did on Jake's roof, that's usually when it's worth getting a replacement price. You can see what a replacement runs in my roof replacement cost guide for Washington, PA.
What a roof replacement with me includes
- Satellite measurements and an in-person walkthrough of the roof
- A written estimate priced per square, labor and materials included
- Local permits wherever they're required
- Full tear-off of the old roof, with rotted decking replaced where we find it
- Owens Corning Duration shingles
- Cleanup with a magnetic nail sweep
- A 5-year workmanship warranty at no charge, sometimes 7. A 10-year warranty is an extra $600.
I'm on every job unless I'm grabbing lunch or running for materials. You can see more of our roofing services and the towns we cover, from Washington and Monongahela to Mt. Lebanon, Upper Saint Clair, and McMurray.
Common questions
What is the average cost of a new roof in PA?
I can only speak for my part of the state. Around Washington County I charge $600 to $700 per square, and a square is 100 square feet of roof, labor and materials included. A 20-square roof usually lands between $12,000 and $14,000, plus any rotted decking we find at tear-off. I broke the full pricing down in my roof replacement cost guide.
How much does it cost to replace the roof on a 1,400 square foot house?
It depends on the roof, not the house. The roof is usually bigger than the living space because of the pitch and the overhangs. If the roof itself measures 1,400 square feet, that is 14 squares, so about $8,400 to $9,800 at my rates, with steep or complicated roofs at the top of that range.
Do I need a permit to replace a roof in PA?
Under the state building code, a residential re-roof has not needed a building permit since October 2018, but the work still has to meet the code. If rotted sheathing or framing has to be fixed, a permit comes back into play, and some towns have their own rules. I pull local permits wherever they are required, so that part is on me.
Should a 20-year-old roof be replaced?
Not just because of the number. InterNACHI puts basic 3-tab shingles at about 20 years and architectural shingles at about 30, so a 20-year-old roof is due for a close look, not an automatic tear-off. If it is leaking, missing shingles after storms, or needs the same repair over and over, it is time to get a replacement price.
What is the most expensive part of replacing a roof?
The biggest swings come from pitch, height, and difficulty. A walkable one-story roof is at the low end of my pricing, and a steep, tall, or complicated roof is at the high end. The other wild card is rotted decking under the old shingles, which nobody can see until the tear-off, so I price it separately.
What is the best time to replace a roof?
Shingles are not supposed to go on below 45 degrees, and you want two good days of 45 and above so you are not putting frozen shingles on a roof. Around here that means replacements mostly happen April through October or early November. If your roof is on its last legs, don't wait until it's too late and end up nursing it through a winter.
Is it cheaper to put a metal roof or shingles?
Shingles cost less up front, and about 90 percent of the roofs I do are shingles. Metal costs more, but InterNACHI puts it at 40 to 80 years compared to about 30 for architectural shingles. I install both, so we can talk through which one makes sense for how long you plan to stay in the house.
What is the 25% rule for roofing?
It is the idea that once repairs cover 25 percent of a roof, the whole roof has to be replaced. Pennsylvania does not have a statewide rule like that. A few municipalities use 25 percent as a cutoff for when a repair needs a permit, which is a different thing, so check with your township if you hear it from a contractor or an adjuster.
How can you tell if a roofer is lying?
Watch how the estimate is built. If the number keeps growing with line items for this material and that material, ask why. Make sure they are licensed in Pennsylvania, ask who will actually be on your roof, and be careful with out-of-town crews that show up right after a storm. And see if they answer the phone before you sign, because it only gets harder after.
Not sure how much life your roof has left?
Call me at (412) 610-2378. I answer my own phone, and if I'm up on a roof I'll call you back. I'll walk the roof, tell you what I see, and write the estimate before I leave. You can also read what customers say first.
Owens Corning preferred contractor · Nextdoor Neighborhood Favorite 2024 and 2025 · Licensed, bonded, and insured in Pennsylvania (#151398)
