Roofing Guide · Updated 2026
What is a composition roof?
Composition roofing is the industry name for asphalt shingles made from several bonded layers. It is durable, cost-effective, and the most common residential roof in the Pacific Northwest. Below: how it's built, what it costs in 2026, how long it lasts, and when to choose it over metal.
Composition roof = asphalt shingle roof
The terms are used interchangeably. Modern composition shingles combine a fiberglass reinforcing mat, waterproof asphalt, protective mineral granules, and an adhesive seal strip. Together, these layers shed rain, resist wind, and protect the roof deck from ultraviolet exposure.
There are three product tiers: 3-tab (flat, budget, ~20 year), architectural / dimensional (the standard today, ~30 year), and designer / luxury (thicker, varied profiles, 50-year warranties).
Layered protection
Fiberglass, asphalt, and mineral granules work together as one weather-resistant system.
PNW durability
Quality architectural shingles handle rain, wind, temperature swings, and moss-prone seasons.
Strong value
Composition roofing balances installation cost, curb appeal, repairability, and service life.
How much does a composition roof cost in 2026?
In Washington and Oregon, full composition roof replacements typically fall in the ranges below. Pricing varies with pitch, layers to tear off, ventilation upgrades, skylights, chimneys, and the shingle line you pick.
| Home | Shingle | Installed cost |
|---|---|---|
| 1,500 sq ft ranch | 3-tab shingles | $8,500 – $11,500 |
| 1,500 sq ft ranch | Architectural | $10,500 – $14,500 |
| 2,500 sq ft two-story | Architectural | $14,000 – $20,000 |
| 2,500 sq ft two-story | Designer / impact-rated | $19,000 – $28,000 |
| Complex / steep / multi-dormer | Architectural | Add 15–30% |
Ranges reflect 2026 PNW market pricing including tear-off, underlayment, drip edge, basic flashings, and standard cleanup. Get a written estimate for your actual roof.
How long does a composition roof last?
Architectural composition shingles commonly last 25 to 30 years when installed with proper ventilation, flashing, and underlayment. Premium impact-rated products may last 40–50 years. In Washington and Oregon, routine gutter cleaning, moss control, and periodic inspections help prevent trapped moisture from shortening that lifespan.
Pros
- Lowest installed cost of any long-term roof system
- Hundreds of color and profile options
- Easy and inexpensive to repair section by section
- 25–50 year manufacturer warranties available
- Algae-resistant lines handle PNW moisture
Cons
- Shorter lifespan than metal, tile, or slate
- Granule loss accelerates in hot, sunny exposures
- Heavy moss can shorten lifespan if untreated
- Less wind resistance than standing-seam metal
Is composition roofing right for your home?
It is a practical choice for most sloped homes: many colors and profiles, easier to repair than specialty materials, and a fraction of the cost of standing-seam metal or natural cedar. The best product for you depends on roof pitch, ventilation, tree cover, budget, and the warranty you want.
Looking at metal instead? See our roof systems overview, or jump straight to residential roofing services.
Composition roof FAQs
What does composition roof mean?+
A composition roof is the industry term for an asphalt shingle roof. Each shingle is composed of a fiberglass mat saturated in asphalt and coated with mineral granules — hence 'composition.' It is the most common residential roof in the United States.
How much does a composition roof cost in Washington?+
For a typical single-family home in Washington and Oregon in 2026, a full architectural composition shingle roof replacement runs about $9,000 to $18,000 depending on roof size, pitch, layers being torn off, ventilation upgrades, and shingle line. Premium designer shingles and complex roofs can run higher.
How long does a composition roof last?+
Architectural composition shingles typically last 25 to 30 years in the Pacific Northwest. Premium impact-rated and designer products are warrantied up to 50 years. Lifespan depends heavily on attic ventilation, tree cover, moss control, and installation quality.
Composition shingles vs metal roofing — which is better?+
Composition shingles cost less up front, are easier to repair, and come in many styles. Metal lasts longer (40–70 years), sheds debris and snow better, and qualifies for some insurance discounts, but costs roughly 2–3x more installed. For most PNW homes, architectural composition is the best value.
Can I install a new composition roof over my old one?+
Washington and Oregon code generally allows one layer of overlay, but we almost never recommend it. A full tear-off lets us inspect the decking, replace rotten sheathing, upgrade underlayment and flashings, and gives the new shingles their full rated lifespan.
Do composition shingles handle Pacific Northwest rain and moss?+
Yes — modern algae-resistant architectural shingles are designed for wet climates. Adding zinc or copper strips at the ridge, keeping branches trimmed back, and cleaning gutters annually will dramatically extend the life of the roof.