How long does a roof last in southeastern PA?

It depends mostly on what is on your roof

• Three-tab asphalt shingles: about 15 to 20 years. The flat, single-layer shingle with three even tabs. Plenty of older roofs around here are still three-tab.
• Architectural asphalt shingles: about 25 to 30 years. Two layers laminated together, thicker and heavier, with a textured look. This is what we install on new shingle roofs.
• Metal: typically outlives two shingle roofs. It costs more up front, so it makes the most sense if you plan to stay in the house a long time. (Question for Jim: how many years Jim is comfortable publishing for a standing seam metal roof installed by Armstrong)
• Slate: a sound slate roof can outlast several shingle roofs. On older houses the slate often outlives its nails and flashing, which is why slipping slates are usually a repair, not a reason to tear the roof off.
• Flat roofs (EPDM rubber, modified bitumen). (Question for Jim: how many years a flat roof over a porch or addition typically lasts around here, for EPDM and for modified bitumen)

Those are ranges for a roof that was installed right and has a properly vented attic. The tool below takes the year your roof went on and the shingle type and gives you a rough idea of where you are. Then go look at the actual shingles, because that is what really decides.

Why some roofs around here give out early

• A hot attic. Without good intake vents at the soffits and exhaust at the ridge, a summer attic cooks the shingles from underneath. It is a common reason a roof wears out years ahead of schedule.
• Freeze-thaw winters. Our winters swing above and below freezing over and over. Water that gets into a crack freezes and opens it wider, and snow that melts and refreezes at the gutter makes ice dams that push water under the shingles.
• Trees. Shade keeps moss and algae growing, branches scrape off granules in the wind, and leaves pack the valleys and gutters so water backs up. A roof under a big oak often wears unevenly.
• Sun on the south side. The south and west slopes get the most sun and usually go first. The back of the house can look worn years before the front.
• A second layer. Shingles nailed over an old layer run hotter and usually do not last as long as shingles on a clean deck.

What we see on roofs around Horsham

Most of the houses we work on went up between the 1950s and the 1990s, so most are on their second or third roof by now. The post-war Capes, ranchers and splits in Willow Grove, Hatboro and Warminster have simple roofs that wear fairly evenly, and on a lot of them the question is whether the three-tab roof from the '90s has anything left.

The bigger colonials in Blue Bell, Dresher and Maple Glen are usually on architectural shingles, but all those valleys and wall joints mean a roof can leak at the flashing well before the shingles themselves are done. In the older boroughs like Ambler, Lansdale, Abington and Doylestown, steep roofs and mature trees shorten the life of the shingles, while slate on the oldest houses can keep going much longer.

Ventilation is the part people forget. Insulation pushed up against the soffit vents, or no ridge vent at all, cooks the shingles from below, and a new roof on that attic ages the same way the old one did. (Question for Jim: does Armstrong check and correct attic ventilation as part of every replacement, and is it included in the price?)

(Question for Jim: at what age Jim typically sees asphalt roofs around here actually needing replacement, and the oldest working shingle roofs he still comes across)

How to tell how much life your roof has left

Find the year first. Closing papers, the seller's disclosure or a township permit usually have it. Then look at the roof from the ground with binoculars, and from the attic with a flashlight on a dry day.

1. Granules in the gutters. A handful after a new roof is normal. A steady pile years later means the shingles are going bald.
2. Curling, cupping or cracked shingles. Edges lifting or tabs cracked across are signs the shingles have dried out.
3. Missing shingles after ordinary wind. When a moderate storm starts taking shingles, the seal strips have given up.
4. Dark streaks or stains in the attic. Stains on the underside of the roof boards, or daylight around nails, mean water is getting in.
5. Patches on patches. If you are calling a roofer every year, the roof is telling you something.

If you are seeing two or more of those, or the roof is near the end of its range, get a free roof inspection. You get photos of everything we find and a straight answer on whether it needs a repair or a replacement. If it does, a full asphalt replacement typically runs $6,500 to $18,000; see what a new roof costs.

One roof that wore out early, and why

(Question for Jim: one recent replacement you're comfortable publishing where the roof was younger than expected: town, house type, shingle type and age, what we found (ventilation, second layer, trees), and what we changed on the new roof)

You can see the scope and photos of recent replacements on our projects page.

When an old roof doesn't need replacing yet

A number on a calendar is not a reason to replace a roof. If your architectural roof is 22 years old but the shingles lie flat, hold their granules and the attic is dry, it may well have years left. Keep the gutters clean, trim branches back off it, and have it looked at every year or two. If there is one leak at a vent or chimney on an otherwise sound roof, that is a repair, not a new roof.

Related questions

How long does a roof last?

An asphalt shingle roof in southeastern PA usually lasts about 15 to 20 years for older three-tab shingles and about 25 to 30 years for architectural shingles, with a properly vented attic. Metal and slate last longer. The condition of the shingles matters more than the age.

What is the lifespan of an asphalt shingle roof in Pennsylvania?

About 15 to 20 years for three-tab and about 25 to 30 for architectural shingles in our part of the state. Freeze-thaw winters, heavy shade from trees, a hot attic and a second layer of shingles all shorten that.

How long does a metal roof last?

A well-installed metal roof typically outlives two shingle roofs. It costs more up front, so it pays off mostly if you plan to stay in the house a long time. (Question for Jim: a year range for metal roofs Jim is comfortable publishing)

Can a shingle roof last 30 years?

An architectural shingle roof can reach about 30 years when it was installed over a clean deck and the attic is properly vented. Most three-tab roofs do not. Watch for granule loss, curling and cracking rather than going by the date alone.

How often should an older roof be inspected?

Once your roof is about 15 years old, have it looked at every year or two, and after any major storm. Our inspections are free and come with photos.