Why Is My Flat Roof Cracking And Bubbling

Flat roofs can be a great addition to any building, but they are not free from issues. Flat roof blistering and flat roof bubbling are two common problems which can result in your flat roof cracking. 

Flat roof blistering is a problem that results in bubbles forming underneath the roof’s surface. These bubbles often lead to cracks that can affect the overall integrity of the roof. Alligatoring is a related problem which occurs when the membrane of your roof develops cracks and begins to peel.

In order to maintain the longevity of your flat roof, it is important that you correct blistering and alligatoring to prevent future problems. Let’s look at each in turn.

What causes flat roof blistering?

Blisters on the membrane can create various problems. It can result from leaks or just the extreme heat from the sun. Whatever the cause, these unaesthetic and potentially hazardous blisters are a serious problem as it can also reduce the lifespan of the flat roof. 

The membrane will therefore not stay sealed if there is moisture between it and the roof deck. This can happen for a number of reasons: leaks, freeze/thaw cycles, or improper ventilation for instance. The result is a roof that resembles a desert landscape with ups and downs in the surface and rounded “bubbles” beneath it. 

How to fix flat roof blistering

If flat roof blistering is really bothering you, consider having it patched to make your roof look better and also prevent future potential costly damage. At LD Roofing Services, we have the processes to quickly and efficiently fix blisters for all types of roofs. You could also consider using certain products listed here that can help fix flat roofing cracking. In most cases, you may not need to fix it immediately but there are several signs that could indicate the need for fixing the blisters on the roof such as the seam opening up, a cracked membrane, and the surfacing on the blistered area coming off.

Shingle blistering is caused by the combination of extreme heat and moisture. The first step to dealing with this type of damage is to remove the shingles and tar, then cut away any remaining damaged section of membrane. Next, apply new rubberised or asphalt-based shingles over the damaged area. Make sure you apply extra material outwards in order to prevent any leaks. You can see our roof repair services here.

Causes of flat roof alligatoring

Alligatoring is a sign that your roof is getting old and shortening its lifespan. When left un-repaired, the roof’s surface may become prone to further damage which will eventually cause problems like ruined walls and ceilings, wood rot, mildew and mould. Over time, alligatoring will appear as cracking on your roof or siding. But you shouldn’t let this seemingly small problem become a big one. It can be prevented if you have the right roofer on the job. 

why is my flat roof cracking
Flat roof alligatoring. Source: PMS Silicone

How to fix flat roof alligatoring

Fixing flat roof alligatoring is among the most common roof repairs needed by homeowners. Alligatoring develops when the membrane of your roof develops cracks and begins to peel, much like an alligator’s skin. 

When a roof shows signs of alligatoring, it is important to make sure you clean the surface correctly before applying a protective coating. Once this has been done, make sure the coating is applied correctly. In the event that blisters appear, however, be sure to repair them immediately for safety reasons.

Facing issues with your flat roof cracking?

If you are facing any type of flat roof cracking, blistering or bubbling then it’s important that you take immediate action as it can only exponentially grow into a bigger problem if left unattended. Do ensure you look for early signs and that they are dealt with utmost care – check our roof repair guide here.

Contact our team of flat roofing specialists at LD Roofing Services for a free quote and consultation. We can help repair any type of flat roof cracking!



LD Roofing Services Ltd is a highly rated and roofing company in Northampton with over 25 years experience offering all types of roofing services across Northamptonshire and NN postcodes.