We often come across misinformation about the term Class 4, or impact rated (IR), asphalt roofing shingles. Some contractors use the terms as a sales tactic to “upgrade” the roof while charging a significantly higher cost to provide this class of shingles. For this topic we are focusing solely on laminate architectural asphalt shingles typically used on residential roofs. So what are Class 4 roofing shingles?
The rating system that governs the impact resistant designations comes from two key organizations. Factory Mutual (FM) and Underwriters Laboratories (UL) both have testing and rating systems for the category. The most common and popular among shingle manufacturers is United Laboratories UL 2218 that created the Class 1 – 4 rating system, with Class 4 being the highest available impact rating.
The testing standard for asphalt shingle roofing products involves dropping a solid steel ball, of different diameters, from a specific height onto the surface of the shingle. The same size steel ball is dropped twice in the same location on the shingle. For each size steel ball the shingle must not sustain any damage to the front or back of the shingle to earn that level of impact resistance rating. The Class 4 rating is completing the test with a 2 inch steel ball size. Seems pretty straight forward right?
Some might say, but steel balls don’t fall out of the sky…balls of ice do. That is the first point of debate over how relevant the classifications are. When there is a hail storm the hail can fall from any angle, impact at varying speeds, and the shape of hail stones can vary widely. The slope angle of the roof the shingle is installed on also plays a factor in the angle of hail strikes. Each of those factors contribute to the extent of potential damage to your roofs asphalt shingles.
Each manufacture has different methods and formulations for producing the asphalt mixture that makes up the bulk of their shingles. The properties of the asphalt mixture and the overall thickness of the shingle product is what primarily affects the strength and resilience of the shingle when impacted. The UL 2218 testing with steel balls does give an indication from a test administered equally to competing products in a controlled method. You just have to keep in mind that mother nature is very unpredictable and this kind of test result cannot indicate real world results.
Asphalt shingle products that claim impact resistance properties have become far more common in the recent decade. The primary characteristic that allows these products to be significantly more resistant to hail and debris impact is the use of polymer modified asphalt. Instead of using basic asphalt mixtures that are cooked at high heat, the polymer modified asphalts have created a less brittle result that often has additives that give them a rubberized property. This allows the shingle to create more of a bounce reaction to impacts and is far less vulnerable to cracking. The polymer modified asphalt mixtures are not new, they have been part of research and development in the industry since the 1970’s. The widespread adoption by the majority of manufactures came much later. Today most manufactures have a polymer modified asphalt shingle product in their lineup.
The Insurance Institute for Business & Home Safety has taken testing a step further than the legacy methods using steel balls. They developed uniform testing methods that utilize actual ice and create impacts to better emulate actual hail stone strikes. Their performance ratings for Class 4 shingles is also benefited by categorizing several aspects of potential damage including dents, tears and granule loss. IBHS testing has provided new and better insight into the way Class 4 shingles might perform in the real world on your roof.
When it comes to Class 4, or any impact resistant rated asphalt shingles, the installation method for most products is identical. The primary characteristic of Impact Resistant or Class 4 shingles is they are significantly heavier per shingle. The extra work for installation is only having to manage the heavier bundles of shingles. The shingle cost is also higher than a basic shingle, typically ranging from 30% to 50% additional material cost. So is the extra cost for Class 4 impact rated shingles worth it?
If your homes roof is relatively old and reaching end of life it can feel like a blessing to have your roof damaged by a hail storm. Having insurance cover the large majority of the cost to have a new roof installed is definitely a plus. The deductible out of pocket portion of an insurance claim is the unpleasant part. Most states have always had stringent requirements for the property owner to pay their deductible portion in conjunction with a casualty claim, such as a roof damaged by a storm. In Texas, unfortunately, there is a long history since the late 1980’s of contractors performing roof replacements while helping the property owner avoid paying anything out of pocket.
As of September 2019 Texas has now updated the law to be on par with most other states and made it a crime for the property owner not to contribute their deductible out of pocket portion to the cost of the restoration covered under the insurance claim. In Texas particularly people not paying anything out of pocket led to very basic quality materials being utilized on roofs. Many homeowners were told that higher quality options weren’t worth the cost or were never offered the details of the options of higher quality materials. After all, the idea you would just get another roof for nothing out of pocket if it was damaged again made it harder to justify looking at more costly material options. For decades around Texas that has resulted in homeowners commonly having a roof replaced multiple times over a relatively short number of years.
This all begs the answer, a better quality roof will last longer, resist storm damage better, look better, and serve to protect your home better. The added cost of a top quality Class 4 impact rated shingle roof system is a great value when you are replacing the roof on your own home. When you consider the out of pocket cost you’re absorbing, you want to make an investment that will considerably reduce the potential of having damage again with future storms. Installing a fresh new roof is nice, but it is also inconvenient and costly. Another consideration is that many insurance companies offer an annual premium discount on homeowners insurance policies for having a certified Class 4 impact rated roof.
There are varying circumstances among property owners that may need additional consideration. If the property value is relatively low, is an investment property, or you plan to sell soon with the rest of the neighborhood having average roofs, the additional cost may not be justified. Whatever shingle material selection you ultimately make, it is important to consider the quality options within the Class 4 rating that will definitely provide a value proposition that is worth the additional cost.