The Age Test
Start with the calendar. In Baltimore's climate — humid summers, ice in winter, wind year-round — architectural shingles last about 20 to 25 years. Three-tab shingles (the flat, single-layer kind on older homes) last 15 to 20. Metal lasts 40 to 70. If your shingle roof is past 22 and showing wear, you are not deciding whether to replace — you are deciding when.
Signs That Point to Replacement
- Widespread granule loss. Check your gutters and downspout splash blocks. Piles of sandy granules mean the shingles' armor is washing off — UV is now eating the shingle itself.
- Curling or clawing across multiple slopes. A few curled shingles on the south face is sun wear; curling everywhere is a dying roof.
- Bald spots or cracked shingles visible from the ground with binoculars.
- Multiple leaks in different areas. One leak is a repair. Three leaks in three places is a roof telling you it is done.
- Daylight through the deck from inside the attic.
- Sagging anywhere in the roofline — that is structural, and it is urgent.
When a Repair Is the Right Call
A repair makes sense when the roof is under 15 years old, the damage is limited to one area — a wind-torn section, one bad valley, a single flashing failure — and the rest of the shingles are flat, flexible, and holding granules. A good repair on a young roof buys real years. We will tell you when that is the case.
The Gray Zone
Roof is 18, one leak, shingles look okay otherwise? You have options. Replace proactively and sleep through the next storm season, or repair and budget for replacement in three to five years. What you should not do is pour repair money into a roof year after year — two or three patches on an aging roof usually add up to real money that could have gone toward the replacement. A free inspection gives you the data to decide.
Timing It in Baltimore
If replacement is coming, sooner beats later for one reason: a roof at the end of its life does not fail politely. It fails during the worst storm of the year, when every roofer in Baltimore County is booked solid and you are paying emergency pricing for tarping. Spring and fall are the most comfortable installation windows, but a good crew roofs year-round in Maryland — we hand-seal shingles in cold weather and schedule around freezing days.