Knowing the difference between roof blistering vs. hail damage on your roof is crucial to preserving its condition. Although blistering and hail damage can both be dangerous, they have different causes and consequences that call for different restoration methods.
In this blog post, we’ll explore what hail damage and roof blistering are, how to tell them apart, and why accurate identification is crucial.
What is Roof Blistering?
Bubble-like formations can develop on a roof’s surface due to trapped air or moisture between layers of roofing materials, like shingles or membranes. When heat causes the trapped air or moisture to expand, these blisters form. This issue can be caused by poor ventilation, manufacturing defects, or improper installation. While small blisters might not cause immediate problems, larger ones can weaken the roof, leading to leaks and further damage if not fixed quickly.
Common Causes of Roof Blistering
- Tree Sap: If there are trees over your roof, sap can build up on the shingles. This sticky substance traps moisture, which can cause blistering over time.
- Improper Installation: If the roof isn’t installed correctly, moisture can get trapped between the shingles and the roof deck. This trapped air expands with heat, causing blisters to form.
- Moisture Trapped Under Shingles: Moisture can get trapped during shingle manufacturing or installation. When the sun heats the roof, this moisture expands, making the shingles bubble up.
- Poor Ventilation: Without proper attic ventilation, heat and moisture buildup can cause shingles to overheat and form blisters.
- High Temperatures: Extreme heat, especially in summer, can worsen blistering. The sun’s rays cause shingles to expand and blister, especially if they are old or of lower quality.
Appearance of Roof Blisters
Generally speaking, roof blisters appear as elevated, uneven lumps on the shingle surface. They can be found alone or in groups, and their sizes might vary. Ignoring them might result in more serious problems, such as leaks and structural damage, even if they might not appear concerning at first.
What is Hail Damage?
Hail damage happens when hailstones strike surfaces like roofs. These hailstones can be as small as peas or as large as grapefruits, hitting the ground at high speeds. Roofs are especially vulnerable, as hail can cause leaks and structural problems that often go unnoticed until more damage occurs. In the U.S., hailstorms cause billions of dollars in damage every year, making them a significant weather threat.
Common Causes of Hail Damage
- Hailstone Size: The damage depends on how big the hailstones are. Small ones might cause minor dents or granule loss, but larger hailstones can create deep dents, cracks, or even puncture the roofing material.
- Wind Speed: The wind speed during a hailstorm affects the damage. Strong winds can push hailstones into the roof with more force, making significant damage more likely.
Appearance of Hail Damage
Dents, cracks, or missing granules on asphalt shingles often occur in random spots after a hailstorm. Shingles may feel soft, with exposed fiberglass and weakened sealing strips. On metal roofs, hail may leave dents that are mostly cosmetic. If not repaired, this damage can lead to leaks, water damage, and faster roof wear.
Signs Of Roof Blistering vs. Hail Damage
| Roof Blistering | Hail Damage |
| Raised Bubbles: Small raised areas on the roof surface, usually 1 to 2 inches wide, that feel soft to the touch. | Dented Shingles: Dents or cracks that look like small dimples. |
| Soft Spots: Parts of the roof that feel soft or spongy when walked on. | Dented Shingles: Dents or cracks that look like small dimples. |
| Curling Shingles: Shingles that curl or lift at the edges, often near blisters. | Cracks or Breaks: Cracks or punctures in the shingles, often from larger hailstones. |
| Cracks: Cracks left behind after blisters pop, allowing water in. | Dark Spots: Dark spots or bruises on shingles from hail impact. |
| Scattered Pattern: Blisters appear randomly across the roof. | Dented Metal: Dents in metal parts like vents or gutters. |
Understanding The Difference: Hail Damage on a Roof vs. Blistering
1. Size and Shape
Roof blisters are usually larger and have an irregular shape. Their size and shape depend on how much heat has built up and how much moisture is trapped under the surface. Hail damage, on the other hand, looks like smaller, more circular or oval dents. The size and shape of these dents vary depending on how big the hailstones are and the angle at which they hit the roof.
2. Number of Spots
Blistering might only show up in one or two spots on the roof. This happens because heat and moisture buildup are often concentrated in specific areas, such as those in direct sunlight. In contrast, hail damage typically results in more dents spread across the roof. This scattered pattern is due to hailstones striking different areas during a storm.
3. Depth
Blisters are usually shallow, affecting only the surface of the roofing material. This is because they form from swelling caused by heat and moisture, rather than a forceful impact. Hail damage can go deeper, depending on the size and speed of the hailstones. In severe cases, hail can even crack or break through the roofing material.
4. Severity
Shingle blistering usually starts as a cosmetic issue but can become more serious if left untreated. As blisters pop, they can cause leaks and further damage the roofing material. Hail damage is often more severe right away, posing an immediate risk of leaks. Dents and punctures from hail can let water into the roof, leading to potential water damage.
5. Pattern
Blistering is random and can appear in various spots on the roof, depending on where heat and moisture get trapped. Hail damage often follows a more predictable pattern, aligning with the storm’s direction. The dents from hailstones may form a linear pattern based on how the storm moved.
5. Insurance Coverage
Blistering is typically not covered by homeowners insurance unless it’s due to improper installation or a material defect. Hail damage is more likely to be covered since it’s considered a natural event. Homeowners should review their insurance policies and file claims promptly after a hailstorm to ensure repairs are covered.
6. Repair Methods
Fixing blistering usually involves removing and replacing the affected shingles. Sometimes, patching blisters is possible, but it’s often a temporary solution. For hail damage, repairs might involve replacing damaged shingles, applying sealants to small dents, or even replacing the entire roof if the damage is severe. A professional assessment is often needed to decide the best approach.
7. Seasonal Considerations
Blistering can happen any time of year but is more common in warmer months due to heat buildup. Homeowners should be extra vigilant during these months to catch blistering early. Hail damage is most common during spring and summer storms, especially in regions with severe weather. Homeowners in these areas should inspect their roofs after storms.
How to Inspect Your Roof
- Visual Inspection: Look for raised bumps or blisters for signs of roof blistering. For hail damage, check for circular dents and areas where granules are missing.
- Check for Leaks: Inspect your attic and ceilings for water stains or leaks, which could indicate damage.
- Consult a Professional: If you’re unsure about the damage or how to fix it, contact a professional roofer for a thorough inspection and advice.
> Touch Test: You can also do a touch test to tell the difference between blistering and hail damage. Blisters feel soft or spongy because air or moisture is trapped underneath. Hail damage, however, feels hard and solid due to the impact of hailstones.
Why Accurate Identification Matters
Insurance Claims
Correctly identifying roof damage is key when filing an insurance claim. Insurance companies need detailed proof to decide if the damage is covered. Confusing blistering with hail damage, or the other way around, might lead to denied claims or lower reimbursements for repairs.
Repair and Maintenance
Right identification ensures proper repairs. Mistaking hail damage for blistering could miss serious issues, while confusing blistering for hail damage could lead to unnecessary costs. Accurate identification helps extend your roof’s life and prevents future problems.
Conclusion
Understanding roof blistering vs. hail damage is important for keeping your roof in good shape. Each type of damage looks different and needs different repairs. Regular inspections and quick fixes can prevent bigger problems and save money. If you think your roof is damaged, consult a professional for the right assessment and repair. Your roof protects your home, so take care of it!
At All Around Roofing, Siding & Gutters, we specialize in repairing all types of roof damage, including blistering and hail damage. Our experienced team can provide a thorough inspection and guide you through the repair process, ensuring your roof remains in top condition. Contact us today at (937) 902-2839 to schedule a roof inspection and protect your home.
