Roof Damage Caused by Hail
Roof Damage and How Hail Affects Roofs
I have seen the aftermath of golf ball and even some tennis ball-sized hail and the damage associated with roofs and everything else. Vinyl siding was damaged, cars were damaged, steel siding was damaged, the roofs had golf ball divots. What withstood the damage better than anything? SBS shingles. The rubber-based ones like Certainteed NorthGate. Even some of the newer Landmark shingles took a beating without showing roof damage. Hail bigger than 1” can cause some substantial roof damage. Leaks can happen but are pretty rare. The ridge cap is the most susceptible. These are the little cap pieces that cover where the shingles meet on a peak or hip of a roof. If a little crack does occur from hail damage, it may not amount to much. Several damaged ridge caps may require a temporary patch Wind-driven hail can easily damage a roof on entire roof planes. Roofs under 5 years old can really handle what mother nature throws at them especially hail. Hail damage will easily take five to ten years off your roof life. Even the pea-sized hail will damage and “sandblast” a roof removing the granules in the process. Granules are the grit that provides color and protection from UV rays is gone, and the shingle will go downhill fast. What Causes Granule Loss on Shingles? Read more about this.
The steepness of the roof and position of the home can make a big difference with the severity of hail damage. A flatter pitch such as 4/12, a very common walkable roof, will show more damage than a very steep roof when hail travels straight down. The steeper pitched roof can have a skipping effect with the hail versus hitting it close to perpendicular with the shallower pitched roof. Mother nature has got a plan for steep roofs as well. Wind-driven hail will damage the planes of these roofs depending on the direction of the storm. One roof plane may sustain heavy shingle damage, and the other sides of the roof may not.
Hail does crazy things during a storm and can almost pick individual houses or wipe out an entire block. Some shingles are fairly resilient others get walloped. It’s completely random. Trees are great at slowing down wind-driven hail. Even a neighbors house can take the brunt, leaving your home unscathed. The density of hail can also make a big difference in the impact it has. Imagine hail just rolling around high in the atmosphere, freezing layer by layer. It can be super chilled and very hard or just at the freezing point and relatively mushy. Hail can reach a velocity of 90 mph, falling straight down with no forces applied to it. With a little wind hail and the right conditions, hail can form into aerodynamic discs that can jet through the air horizontally, causing unbelievable damage to roofs and siding. The picture above shows these hail discs.
What does hail damage do to a roof?
Hail normally creates a bruise on the shingle knocking granules loose and exposing the asphalt. Once the asphalt is exposed, the life of the shingle becomes greatly reduced. With extreme hail damage, the shingle mat can be damaged, actually cracking the shingle. Roof leaks after a hail storm are often a primary concern with homeowners. The straightforward answer is hail associated roof leaks are not common unless the hail is huge. Roofing companies wanting naïve homeowners to sign a contract can paint a pretty vivid picture of homeowners placing buckets randomly throughout the home. The insurance adjuster is a good resource to discuss how fast one should act on a roof replacement.
Here are some things adjusters look at to determine how severe the roof damage is:
Down Spouts and Gutters - These items are considered soft metals and will dent very easily. Gutter and downspout damage proves that hail was there and verifies further investigation is needed.
Hail Damage on Siding - When hail damages steel or vinyl siding, there is a high probability it affected the roof as well. Siding damage tells an adjuster that the hail was wind-driven and not traveling straight down.
Roof Damage with Hail - Smaller hail with the force of the wind behind it can really do some substantial damage. Hail is not known as a leak causer but compromises the integrity of the shingle leading to future issues.
Roof Vents - Roof vents that are aluminum can really show damage, whereas a galvanized painted vent takes a lot more force to damage it. Plastic roof vents can crack or have holes punched right through them!
Metal Roof and Ag Steel - Metal buildings such as pole barns will dent and easily be seen at the right angle. If some imperfections are noticed above 6’, Damage related to hail will most likely be on the roof as well.
Hail bruise on a shingle causing granule loss and damage to the shingle mat.
Several hail hits caused the roof damage on this 10 year old shingle.
Hail Resistant Shingles
Class 4 shingles can minimize hail damage done to a roof. These shingles offer resistance to damaging hail larger than 1-1/2”. To be honest, I have seen the SBS roofs hold up to hail upwards of 1”. This type of shingle can be a stone-coated steel shingle or an SBS shingle. An impact-resistant shingle can withstand hail because of the weight and material composition. A standard architectural shingle is asphalt-based, where SBS is more of a rubber-based material that can absorb a hail hit. A stone-coated steel shingle can withstand the hail hit because of the galvalume base and stamped sheet metal construction. With these shingles, some insurance companies offer reductions on insurance premiums because these roofs are less likely to be damaged from hail.
Hail Damage on a Roof Can be Subjective
Roof inspections are sometimes up for debate. Adjusters have seen things I have not seen, and I have seen things an adjuster does not see. Sometimes what I thought was hail damage is considered wear and tear. The most professional thing anyone can do, including the roofing contractor, is not overpromising that they will get the roof covered to the homeowner. This puts too much pressure on the situation and almost a need to produce a replacement roof claim because of the promises made. It can result in tantrums between homeowners, adjusters, and roofing contractors.
An Engineers Report that Correlates Hail Size with Asphalt Shingle Damage
Numerous studies have been conducted on asphalt shingles concerning hail. The “threshold” hail that starts to show evidence of damage to asphalt shingles has been documented to be on the order of:
• 1-inch diameter for Organic Based Shingles
• 1.25-inch for 3 Tab Fiberglass Shingles
• 1.5-inch to 1.75-inch for fiberglass Architectural Shingles.
Therefore, knowing the approximate hail size at a specific location is important; however, many conditions ultimately determine whether hail causes damage to a certain roof.
The mere existence of a blemish on a roof does not necessarily mean it was hail. Roof shingles acquire blemishes for many reasons. There are all sorts of blemishes of granule loss that appear on a roof. Hail blemishes have a distinct look. If the hail is soft and small, it causes no damage.
Hail damage is the result of a hard ice mass that impacts a roof. As the ice mass increases in size, the amount of energy of the ice impacting the roof increases dramatically. Damage from hail can be granule loss, bowl-shaped depressions, fractures, and punctures. Often the hail creates donut-shaped blemishes as the interior granules are pushed into the mat, and the perimeter of the impact displaces granules. Source: Abbott Consulting Forensics & Design LLC
Here are some other topics related to hail damage and roofs