How Long Does a Roof Last in Western Washington?

Architectural asphalt shingles are the most common roof on Tacoma homes. There's no single number that fits every asphalt roof, because two identical shingles can wear very differently. One installed over good underlayment with proper attic ventilation on an open, sunny lot will usually outlast the same shingle on a poorly vented attic under dripping firs.

A useful rule of thumb from our own replacement work: once an asphalt roof is 20+ years old and the shingles are curling, cracking or going bald (losing their granules), it's usually time to plan a replacement rather than keep patching. If your roof is 15+ years old and nobody has looked at it, that's a good time for a free roof inspection.

Standing seam metal is the long-haul option. A quality standing seam roof commonly lasts 40–60 years. It sheds rain quickly and doesn't give moss and fir needles much to hold onto, which is a big advantage in our climate.

The trade-off is cost: standing seam metal typically runs about 1.8 to 2.5 times the price of an asphalt roof. For homeowners who plan to stay put for a long time, that longer life can make sense. Learn more about metal roofing or see how much a new roof costs for both materials.

Western Washington roofs rarely fail from heat. They wear out from water that sits too long. The most common culprits:

• Long rainy seasons that keep shingles and decking damp for months
• Moss and shade, especially on north-facing slopes and lots with big evergreens. Moss holds water and lifts shingle edges; read how moss damages roofs in the Pacific Northwest
• Fir needles and clogged gutters that back water up under the roof edge
• Wind that lifts shingle tabs, ridge caps and flashing during fall and winter storms
• Poor attic ventilation, which traps moisture and heat under the roof deck
• Worn or poorly installed flashing around chimneys, vents, skylights and walls

Walk around your house and look up, or check from a window. Warning signs include:

• Shingles curling, cracking or bald across large areas
• Granules collecting in your gutters or at the bottom of downspouts
• Moss that has been growing for years and lifted shingle edges
• Leaks in more than one spot, or water stains on ceilings or attic decking
• Soft or sagging areas on the roof
• Repairs that keep coming back on an older roof

One of these on its own doesn't always mean a new roof. Several together on a roof that's 20+ years old usually does.

If the damage is in one area and the rest of the roof is sound, a repair is often the right call: a lifted piece of flashing, a few blown-off shingles or a cracked pipe boot. When the roof is older, the wear is spread out and leaks keep showing up, putting more money into repairs usually stops making sense.

Our roof repair vs. replacement guide goes deeper. When DHT replaces a roof, you get upgraded underlayment, proper attic ventilation, a manufacturer material warranty plus DHT's 10-year workmanship warranty.

A little maintenance goes a long way in our climate:

• Clean gutters in fall and again in winter, after the needles and leaves come down
• Keep moss under control before it lifts shingles
• Trim branches that hang over the roof and keep it shaded and wet
• Get an inspection after major windstorms, and in the fall before winter storms arrive
• Fix small leaks quickly before water reaches the decking and insulation

Not sure where your roof stands? A free inspection gives you photos and an honest recommendation, including when a repair is all you need.