Hail can damage a roof even without any visible leaks. Most of the time hail weakens the roof’s protective system before water can find an entry point and it is visible to you. Hail related roof failures usually appear long after the storm has caused the damage. Your roof has multiple layers and hail usually damages one or more layers without fully penetrating the roof. This allows your roof to remain watertight for a period while its service life is quietly diminished.
Oklahoma is in the middle of warm and moisture rich air from the Gulf of Mexico and dry air descending from the Rockies. This collision of air fuels supercell thunderstorms capable of producing large hail with dense and layered ice cores.
Supercell updrafts take these hailstones through freezing layers which increase the size and density of hail. Even the hailstones with moderate diameter in Oklahoma carries higher impact energy than hailstones of similar size in other places.
The unpredictable pattern of strom only increases damage. The hail storms move in oblique angles due to the powerful horizontal winds. As a result, hail strikes the roof unevenly, damage is concentrated on windward side while the leeward side is almost unaffected.
The temperature also change rapidly after storm. Oklahoma can experience daily change in temperature to the extent of 30 to 40 degrees. This kind of temperate change expands the microfracture created by hail and worsens the damage which makes even minor impact damage cause roof failure over a season or two.
The underlying materials are protected from ultraviolet radiation and environmental stress with the granules on shingles or coating on metal panels. When hail damages these layers, your roof starts aging fast without any visible leaks.
Hail creates microfractures and compressed zones in the shingles, membranes, and insulation. This kind of damage can weaken the structure of the material, which is later aggravated by weather conditions until leaks start becoming visible. The roof keeps working for some time, but its remaining lifespan is shortened.
Hail can remove mineral granules from asphalt shingles. Signs include:
Granules don’t make your roof waterproof directly, instead, they shield the asphalt from ultraviolet radiation and any mechanical wear. Once the granules are gone, the asphalt will oxidize fast and become brittle and eventually crack sooner than expected.
This is functional damage. The roof loses performance despite being free of leaks.
Loss of granule reduces shingle flexibility and reduced flexibility increases the possibility of wind damage risk during storms, even when you don’t see any leak after a storm.
A bruise is a small soft area where the asphalt and fiberglass mat has been crushed under the surface.
Characteristics include:
Bruising fractures the reinforcement fibers inside and over time thermal cycling, movement of wind, and foot traffic can cause these weakened zone to break. You will find leaks after this break happens.
This shows the reason for delay for the appearance of the damage that comes from hail after a storm.
When hail is combined with wind, it can create small cracks across shingles without removing them.
These cracks may:
Water is temporarily redirected due to the overlap of shingle courses and the underlayment. With the widening of the crack or as the granules erode along the fracture line, water begins bypassing intended drainage paths.
Modern day shingles depend on the adhesive strips to bond with the overlapping tabs. Hail impact can damage this bond without moving the shingles visibly.
Consequences include:
Roofs usually don’t leak in the early stages. When the damage from repeated storms is enough to lift the loosen shingles, the rain finds a way inside the house.
Hail impact is visible on metal roofs that doesn’t leak immediately.
These dents:
The roof may perform properly for some years, the coating failure and corrosion develops with time, especially when the water finds other ways to move beyond the drainage.
Cosmetic damage and functional metal damage is different in the eyes of the insurer but even cosmetic denting can reduce the lifespan and decrease the value of your property.
Hail can damage roofs with low slope by compressing insulation under the membranes without actually puncturing the surface.
Effects include:
The membrane may stay watertight at first but as the insulation loses compressive strength, water accumulation increases its exposure to UV radiation and thermal stress, which may cause the seams to fail or result in leaks over the time.
Hail just starts the damage process and it doesn’t complete the failure, hence, it is common to see delayed leaks.
Once the roof loses the layers of protection, UV radiation damages the exposed materials rapidly. The asphalt embrittles, the coatings start cracking, and the membranes lose elasticity.
This process can cause your roof to fail much earlier than you anticipated.
The roofing materials expand and contract due to the daily swing in temperature, which widens the microfractures created by hail. Each cycle increases the damage incrementally.
Over thousands of cycles, the hairline fractures become open splits which results in leaks.
Water may not travel down straight, it can move laterally along with underlayment seams, the joints of the decking, and the lines of fastener.
Even a small breach created by hail will allow water to enter from away from where interior staining appears, creating confusion between the cause and effect.
There is a difference between functional and cosmetic damage as set out by building science and insurance policies.
Commercial structures and some residential houses use roof materials with low slopes, like TPO, PVC, EPDM, and modified bitumen.
Large hail punctures membranes directly or compresses insulation under the membrane. When an insulation is bruised, they deform under load and creates depressions where water gets collected.
And this collection of water increases the explore of the roof to UV rays and thermal stress which speeds up the aging of the membrane and seam failure.
Hail impacts near seams, terminations, and penetrations can:
Seam integrity is important for roofs with flat top and localized hail damage can produce uneven consequences.
Roof Repair in Oklahoma or roof replacement in Oklahoma is often justified when:
These indicators show that impact forces are important enough to get it checked by professionals.
You can’t understand the severity of damage from the ground.
They also check whether the damage is isolated and it can be repaired, or if you needs a replacement.
