Do I Need Class 4 Impact-Rated Shingles on My Seattle Roof?

Are you worried your current shingles won’t hold up in Seattle’s relentless rain and windstorms? Not sure if getting Class 4 impact-rated shingles would be overkill? 

For many Seattle homeowners, it’s hard to know if a more expensive, impact-resistant shingle is worth the investment, especially in a region that doesn’t deal with hailstorms like other parts of the country. But while hail isn't the issue here, constant moisture, high winds, and falling debris from ever-shedding pine and fir trees are.

At RoofSmart, we assess your roof’s needs during inspections and then pair that with your budget and aesthetic preferences to make recommendations on which roof is right for you. Using this method, we help hundreds of customers find their perfect roof every year. 

In this article, we’ll explain what Class 4 impact-rated shingles really mean, how they hold up in Seattle weather, and whether they’re the right fit for your home (and your budget).

What does it mean when a shingle has a Class 4 impact rating?

When a manufacturer comes out with a new shingle, they test its strength and durability using the UL-2218 Impact Test, which is an official rating of how well each shingle handles impact from debris. Class 4 is the highest rating. 

Class 1 and 2 shingles aren’t very strong, so you typically do not see any shingle manufacturers advertising the class rating unless they have a product that’s a Class 3 or 4. 

A steel ball is launched at the shingle, and it passes the test if there are no cracks. The ratings range from Class 1 to Class 4 and are determined by the size of the steel ball used during the test. 

The steel ball is dropped on the shingle from 20 feet up, and if no mark is left on the shingle, it earns its class rating. 

Having a Class 3 or 4 rating means that the shingles can withstand some hits from small debris. It’s a good thing to look for if you want to make sure your asphalt or rubberized roof is impact-resistant. 

Do Class 4 shingles perform better than Class 3 shingles in Seattle’s rain and wind?

The difference between these two ratings is that a Class 3 shingle is tested using a 1.75-inch steel ball dropped on it, whereas a Class 4 shingle is tested using a two-inch steel ball. 

Generally, a Class 4 shingle is going to be stronger and more durable than a Class 3 shingle. However, both are likely to perform well in the Seattle area.

The biggest difference to consider when deciding between Class 3 and 4 shingles is the material type. Usually, Class 3 and 4 shingles are going to be pretty similar. There won’t be super drastic differences in performance (unless one is rubberized).

On the other hand, not everything that’s rated as Class 4 is an asphalt shingle. For example, Euroshield is rated Class 4 (and it would probably be rated higher if that were an option). 

There is a big difference in performance between a Class 3 or 4 asphalt shingle and a Euroshield shingle. Euroshield is stronger and more durable than asphalt shingles (even ones rated at Class 4). 

Performance Comparison: Class 3 vs. Class 4 Asphalt vs. Euroshield Shingles in Seattle

Here's a table to help you understand and quickly compare the performance differences between a Class 3 and Class 4 shingle. 

What’s the cost difference between Class 3 and Class 4 shingles?

Since Class 3 and 4 shingles are usually pretty similar, there’s not a big cost difference between them. There’s usually about a 5% increase when you move from Class 3 to Class 4 shingles. 

But if you’re moving from asphalt shingles to Euroshield (or another Class 4 equivalent like metal), then you can expect to pay about twice as much as the asphalt shingles. 

Premium materials like Euroshield and metal are more expensive, but they have significantly better impact resistance than asphalt shingles. 

When are impact-resistant shingles right for my Seattle home?

Class 4-rated shingles are usually advertised in other states as being great for protecting your home from hail damage. However, hail isn’t an issue (most of the time) in the Seattle area, so this is not a big selling point here. 

Fortunately, protection from hail isn’t the only benefit of Class 4-rated shingles. Class 4 shingles can also help prevent your shingles from granule loss in the following scenarios: 

• Impact from small debris: Branches, twigs, or other small debris can get blown around during one of Seattle’s windstorms. But having Class 4 shingles means that the granules are more likely to stay in place when hit (in addition to not getting scuffs, dents, or cracks on the shingles).
• Walking on the roof: This is not something that people think about a lot, but walking on your roof for any reason can contribute to granule loss. Usually, Class 4 shingles are stronger, so they’re more resistant to this issue. 
• Snow sliding off your roof: Even the friction of snow sliding off your roof can contribute to granule loss if your shingles aren’t rated at Class 4. We don’t get snow super often in the Seattle area, but it is more frequent than hail. 

This means that having a shingle with a Class 4 rating can also be useful if you’re worried about Seattle windstorms or if your property is surrounded by trees and needs to be cleaned off (and walked on) frequently. 

Seattle homes are often surrounded by trees, so this is a major concern in this area. On top of that, pine and fir needles are constantly shedding or being blown onto the roof, meaning that the cleaning is never-ending for some Seattle homeowners.

Are rubberized asphalt shingles the right long-term roofing choice for Seattle homes?

If you’ve been wondering whether it’s worth spending more on Class 4 for your Seattle home, the answer depends on your long-term goals, your budget, and how much protection you want from our region’s wet, windy climate. 

If you’re interested in a Class 4-rated roofing material, rubberized shingles offer enhanced impact resistance, better flexibility in cold weather, and longer-lasting performance than standard asphalt shingles.

But are they the best fit for your roof?

If you’re still on the fence, the next step is to learn how these shingles hold up in real-world Seattle conditions. 

In the article “Rubberized Asphalt Shingles: Are They Worth It for Your Roof?” we break down the pros and cons in detail, compare performance, and help you decide if rubberized asphalt shingles are worth the upgrade for your home.