Are Class 4 Impact Resistant Shingles Worth It in Hail Country?

What Class 4 actually means

Class 4 is the top rating in UL 2218, an impact test. A two inch steel ball is dropped onto the shingle from 20 feet, twice on the same spot. To pass, the shingle must show no crack in the mat on the back side. Classes 1 through 3 use smaller balls from lower heights.

Note what the test measures: mat fracture, not granule loss and not appearance. A Class 4 shingle can still be dented and still lose granules. What it resists is the crack that lets water through and ends the roof's life.

How they are built

Two approaches. Most Class 4 asphalt shingles use an SBS-modified asphalt, essentially rubber blended into the asphalt, which lets the mat flex under impact instead of fracturing. SBS also stays flexible at low temperature, which is a genuine secondary benefit in North Dakota. The other approach is a polymer or fiberglass backing laminated to the shingle.

SBS-modified is the version worth paying for here, because the cold-weather flexibility matters independently of hail.

The insurance discount is the whole argument

Class 4 typically adds 15 to 25 percent to material cost, roughly $1,500 to $3,500 on an average Minot home. Many insurers offer a premium discount on the wind and hail portion for a Class 4 roof, commonly in the range of 5 to 30 percent depending on carrier and state.

Do this before you decide:

1. Call your agent and ask specifically: what is the Class 4 impact resistant roof discount on this policy, in dollars per year?
2. Ask whether it applies to the whole premium or only the wind and hail portion.
3. Divide the extra shingle cost by that annual number. That is your payback period in years.
4. Compare that to how long you plan to own the house.

A $2,500 upgrade against a $220 per year discount pays back in about 11 years, plus whatever value you assign to the roof surviving a storm that would have totaled a standard one.

What they do not do

• They are not hail proof. Softball-sized hail will damage a Class 4 roof.
• They do not prevent granule loss. Granules still come off, and granule loss is still what ages the roof.
• They do not guarantee a claim will be denied or approved. Adjusters assess the actual damage either way.
• They will not stop cosmetic damage. Some carriers offer cosmetic damage exclusions at a lower premium. Read that clause carefully before accepting it.

When they clearly make sense

• You are in an active hail corridor and have filed a hail claim before
• Your carrier offers a meaningful documented discount
• You plan to stay in the house past the payback period
• You are already replacing the roof, so the upgrade is only the delta, not a new project

When they do not

• Your carrier offers no discount, which some do not
• You are selling within a few years
• You are choosing between Class 4 shingle and standing seam steel, in which case steel wins on hail regardless

Questions we get asked