If you’re staring down a roof replacement in the Pacific Northwest, you’ve probably landed on the same fork in the road most homeowners here eventually reach: metal or asphalt. Both hold up fine in a mild, dry climate. Ours isn’t that climate. Between the rain that barely lets up from October to May, the moss that colonizes anything holding moisture for more than a season, and the tree canopy dropping debris on everything within reach, the PNW asks more of a roof than most of the country does.
Neither material is the wrong answer. But they trade off cost, lifespan, and maintenance in ways that matter a lot more here than they would in a drier climate, and the right choice depends on how long you’re planning to stay in the home and what you’re optimizing for.
Quick Answer: Metal roofing generally outlasts asphalt shingles in the Pacific Northwest—typically 40 to 70 years versus 20 to 30—and resists moss and algae growth better due to its non-porous surface. Asphalt costs significantly less upfront and remains the more common choice regionally. Metal wins on long-term value; asphalt wins on accessibility.
Why the Pacific Northwest Is a Harder Test Than Most Climates
A roofing material that performs well in Arizona or Florida isn’t necessarily built for what our region does to a roof. Sustained rainfall—Western Washington sees roughly 35 to 50 inches a year in much of the service area—prolonged overcast stretches that limit UV exposure and drying time, moss and algae pressure from shade and moisture, and heavy tree canopy in neighborhoods throughout Tacoma, Olympia, and the South Sound all stack the deck differently than they would elsewhere.
That’s the lens worth applying to every comparison below—not “which material is better,” but “which material holds up better under exactly these conditions.”
Metal vs. Asphalt: The Side-by-Side
| Factor | Asphalt Shingles | Metal Roofing |
| Typical lifespan | 20–30 years | 40–70 years |
| Upfront cost (installed, per sq. ft.) | Roughly $4.50–$8 | Roughly $9–$22, depending on material |
| Moss/algae resistance | Moderate—improved with algae-resistant granules | High—non-porous surface resists growth |
| Wind performance | Good, can be vulnerable to wind-driven rain and uplift | Excellent, especially with proper fastening |
| Maintenance | Periodic cleaning, more vulnerable to granule loss over time | Lower—mainly gutter and fastener checks |
| Noise in rain | Minimal (typical PNW complaint is nonexistent with proper decking) | Noticeable without proper underlayment/decking, manageable with it |
| Best for | Homeowners prioritizing lower upfront cost, shorter ownership horizon | Homeowners prioritizing longevity, staying long-term, or heavy tree/shade exposure |
How Long Does Each Roof Actually Last Here?
Asphalt shingles typically run 20 to 30 years, with higher-end architectural shingles landing toward the top of that range under good maintenance. Metal roofing, particularly standing seam, commonly runs 40 to 70 years—meaning a single metal roof can outlast two or even three asphalt roofs installed back-to-back over the same period.
That gap matters more here than in drier regions, because moss, sustained moisture, and reduced UV exposure all tend to shorten asphalt’s effective lifespan compared to manufacturer estimates based on more favorable climates.
Cost Per Year of Roof Life: A Different Way to Compare
Sticker price alone tells an incomplete story. According to 2026 installed-cost data from Fixr and This Old House, asphalt shingles run roughly $4.50-$8 per square foot installed, while metal roofing runs roughly $9-$22 per square foot depending on the material chosen (steel and aluminum on the lower end, copper on the higher end). Spreading those costs over each material’s expected lifespan gives a clearer long-term picture:
| Roofing Type | Typical Installed Cost (2,400 sq. ft. roof) | Typical Lifespan | Rough Cost Per Year |
| Asphalt shingles | $10,800–$19,200 | 20–25 years | $430–$960/year |
| Metal roofing (steel/aluminum) | $21,600–$52,800 | 45–60 years | $360–$1,170/year |
These are national ranges, not PNW-specific quotes, and actual pricing depends on roof complexity, tear-off requirements, and material selection. The pattern holds directionally, though: metal’s higher upfront cost is offset over time by not needing to replace it two or three times in the same span.
Does Metal Roofing Reduce Moss and Algae Growth?
Yes, meaningfully. Moss and algae need a damp, porous surface to establish—exactly what asphalt shingles provide, and exactly what metal’s smooth, non-porous surface resists. Metal sheds water quickly rather than holding it against the surface, which removes the sustained moisture that moss and Gloeocapsa magma (the cyanobacteria behind the dark streaking common on PNW asphalt roofs) both depend on to take hold.
That doesn’t mean metal roofs are entirely maintenance-free in a climate this wet—debris in valleys and around penetrations can still trap moisture locally—but the difference in overall moss and algae pressure between the two materials is real and well-documented across the roofing industry. If algae is already an issue on your current asphalt roof, it’s worth reading through what actually causes that buildup and how to treat it before deciding whether a full material switch is the right move or whether targeted cleaning and algae-resistant shingles solve the problem at a lower cost.
Is Metal Roofing Worth the Extra Cost?
It depends on two questions: how long you plan to stay in the home, and how much you value not thinking about your roof again for decades.
Metal tends to make more sense when:
- You plan to stay in the home long-term (metal’s value proposition weakens considerably if you’re selling within five to ten years)
- Your property has heavy tree canopy or persistent shade, where moss pressure on asphalt would be significant
- You’re prioritizing minimal long-term maintenance over lower upfront cost
- You’re building new or doing a full tear-off anyway, where the labor difference between materials is proportionally smaller
Asphalt tends to make more sense when:
- Upfront budget is the primary constraint
- You’re not planning to stay in the home long enough to realize metal’s long-term value
- Your roof has less tree exposure and moss risk is lower
- You want the widest range of style and color options to match a specific architectural look
Neither answer is wrong. The homeowners who end up satisfied with their choice are usually the ones who made the decision based on their actual timeline and property conditions rather than which material sounded more impressive.
Wind, Rain, and Snow: How Each Material Handles PNW Weather
Wind: Both materials perform well when properly installed. Metal roofing, particularly standing seam with concealed fasteners, tends to have an edge in sustained high-wind events because, unlike asphalt, it behaves as an engineered structural element whose wind resistance can be calculated and tested rather than estimated—and unlike asphaltic materials, that resistance doesn’t meaningfully degrade as the roof ages. Asphalt shingles rated for high-wind zones perform well too, but individual shingles are more susceptible to lifting or granule loss during wind-driven rain than a continuous, fastened metal panel system.
Rain: Both shed water effectively when installed correctly. Metal’s seams and non-porous surface make it particularly effective at directing water away quickly rather than allowing any absorption, which matters over the sustained wet stretches typical of a Western Washington winter.
Snow: Metal’s smooth surface sheds snow more readily than the textured surface of asphalt shingles, reducing the load that accumulates on the roof deck during heavier snow events in higher-elevation parts of the service area.
The noise question: A common hesitation about metal roofing is rain noise. With proper solid decking and underlayment—standard practice on any professional metal installation—the difference in interior noise between metal and asphalt is minimal. The dramatic “tin roof in a rainstorm” sound most people picture comes from metal installed directly over open framing without decking, which isn’t how residential metal roofs are installed today.
What About Repair and Replacement Down the Road?
Asphalt shingles have a practical advantage here: individual shingles can be replaced without disturbing the rest of the roof, which keeps minor repairs simple and inexpensive. Metal panel systems are more durable overall but repairing isolated damage—a dented panel from a large falling branch, for instance—can sometimes mean replacing a full panel section rather than a small patch, depending on the profile.
For homes with heavy, mature tree canopy—common throughout Tacoma, Pierce County, and much of the South Sound—this is worth weighing alongside moss resistance. Metal handles falling debris well overall, but a direct hit from a large limb can dent a panel in a way that a shingle would simply absorb and shed granules from instead.
Financing the Difference
Because metal’s higher upfront cost is the main barrier for a lot of homeowners who’d otherwise prefer it, it’s worth knowing that the price gap between materials doesn’t have to be paid all at once. Spreading a metal roof’s cost over a financing term often brings the monthly difference between materials down to something much more manageable than the total price difference suggests.
The Right Roof Isn’t the Most Expensive One—It’s the Right Fit
Metal and asphalt aren’t competing for the same title. One is built for homeowners who want to stop thinking about their roof for the next several decades; the other is built for homeowners who want a reliable, cost-effective roof without the bigger upfront commitment. Both, installed correctly by people who understand what this climate actually does to a roof, will protect your home well.
About The Roof Doctor
The Roof Doctor is a family-owned and operated roofing company with more than 60 years of experience serving homeowners and businesses throughout the Pacific Northwest. Licensed, bonded, and insured, available 24/7, with most jobs completed in one to two days. Whether you’re weighing metal against asphalt or just want an honest read on which fits your home and budget, we’ll walk through the real numbers with you. Call us anytime—we’re available 24/7 and happy to help.
