What’s Causing My Commercial Roof to Bubble, Blister, or Crack?
Noticing bubbles, blisters, or cracks on your commercial roof can be alarming, especially when you’ve invested time and money into protecting your property. These surface problems might seem cosmetic at first, but they’re often signs of deeper roofing issues that could lead to serious leaks, structural damage, or even full roof failure if not addressed.
At Weather Shield Roofing Systems, we’ve been helping businesses maintain and extend the life of their commercial roofs for over 40 years. If you’re wondering what’s behind these roof surface problems, you’re not alone, and we’re here to explain it in clear, simple terms.
What causes bubbles and blisters on a commercial roof?
Blisters and bubbles usually form when air or moisture gets trapped between the layers of your roofing system. The most common reasons this happens include:
Poor roof installation
If your roof wasn’t properly installed—especially with single-ply or modified bitumen membranes—moisture and air can become trapped between layers. When heat from the sun hits the roof, those pockets expand, creating visible blisters or bubbles. Over time, these can stretch, weaken, or even rupture the roofing material.
Moisture intrusion
Even a small roof leak or trapped condensation can create the perfect environment for blistering. Moisture can seep in due to worn flashings, poor seals, or previous repairs that didn’t hold. Once trapped, that moisture gets heated by the sun, turning into vapor that expands under the roofing membrane.
UV and heat exposure
Commercial roofs take a beating from the sun. Over time, extreme temperature swings (especially in Michigan’s climate) can cause the roofing materials to expand and contract. This movement weakens adhesion and leads to separation between roof layers, eventually resulting in bubbling or blistering.
What causes cracks in commercial roofing materials?
Cracks often appear for different but related reasons:
Aging and weathering
All roofs have a lifespan. As materials age, they become brittle and more prone to cracking. Cracks in an older commercial roof are often signs the roof is approaching the end of its service life, or it hasn’t had regular roof maintenance.
Thermal movement
Temperature changes cause roofing materials to expand and contract. Without proper flexibility, seams and surfaces can crack over time. This is especially common with flat roofs and roofs made from asphalt-based products.
Foot traffic and impact damage
Heavy foot traffic on commercial rooftops can cause wear and tear. Walking on brittle areas or stepping on a weakened blister can cause it to crack or rupture. Equipment installation or debris impacts can also lead to visible surface cracks.
Is roof blistering dangerous?
Yes, it can be. While a small blister might seem harmless, it’s often a red flag. Blisters can trap water, and when they eventually pop or split, they leave an opening for leaks. Left untreated, this leads to costly water damage, mold growth, and insulation problems.
At Weather Shield, we’ve seen many cases where a small roof blister turned into a major leak after a storm or a sudden freeze-thaw cycle.
Should I repair a blistered or cracked roof, or replace it?
This depends on the extent of the damage and overall condition of your roof. Here’s a simple breakdown:
- Minor, isolated blistering or cracking: Often repairable with patching, sealants, or reinforcing materials. These repairs are best done quickly before problems grow.
- Widespread or severe blistering/cracking: May indicate a failing roofing system, especially if the roof is older or hasn’t had routine maintenance. In these cases, partial or full replacement might be more cost-effective long-term.
The best approach is to have a trusted commercial roofing contractor inspect the damage. Our team at Weather Shield can help you decide whether a repair, restoration, or replacement is the right fit, and we’ll always explain your options transparently.
How can I prevent roof blisters and cracks in the future?
Proactive care is the best defense. Here are several ways to extend the life of your commercial roof and avoid bubbling, blistering, or cracking:
Schedule regular roof inspections
Routine inspections—at least twice a year—help identify small issues before they become expensive problems. Catching a minor blister early can prevent a major roof leak later.
Invest in professional maintenance
A program like Max Life Roof Carefrom Weather Shield is designed to maximize your roof’s lifespan by proactively managing damage, sealing weak spots, and providing ongoing monitoring.
Limit rooftop traffic
Only allow trained personnel to walk on your roof. Use walk pads if necessary and avoid stepping on known blisters or soft spots.
Ensure proper drainage
Ponding water increases the risk of blistering and cracking. Make sure drains, gutters, and scuppers are clear and functioning.
Watch the weather
After major storms or temperature swings, it’s wise to schedule a quick inspection to check for hidden damage. If you manage a building in Michigan, brutal winters and summer heat waves are tough on commercial roofs.
When should I call a roofing expert?
If you notice any of the following, it’s time to get your commercial roof professionally evaluated:
- Visible blisters, bubbles, or cracks
- Water stains inside the building
- Ponding water on the roof
- Soft or spongy roof spots
- Recent storms or hail
Even if the roof seems fine from the ground, hidden damage can lead to leaks down the line. An inspection from Weather Shield is fast, affordable, and often helps you avoid much larger costs later.
At Weather Shield Roofing Systems, we’re committed to helping you get the most life out of your commercial roof—without surprise costs or scare tactics. We’ve worked with property managers, building owners, and investors for over four decades, and we understand the unique challenges your roof faces in our climate.
Whether it’s bubbling, blistering, cracking, or something else, our team is ready to help you protect your investment and make informed decisions.
Have questions about your roof’s condition? Contact us here. We’re happy to take a look and give you honest answers.
Sir Maximus Shield
Sir Maximus Shield is the noble protector of rooftops far and wide—a knight forged from Weather Shield craftsmanship and unwavering integrity. From the battlements of factories to the towers of office parks, he stands guard against leaks, storms, and time itself. His quest is simple: to defend every commercial roof with honor, precision, and lasting strength. When he’s not patrolling the skyline, Sir Maximus shares his chronicles of durability, innovation, and the noble pursuit of maximum protection. One roof at a time.
