When you have a flat roof you run the risk of sometimes getting blisters, bubbles, cracks, or membrane ruptures. There can be many different reasons for seeing bubbles and other problems with your flat roof. Some of the reasons include: improper cleaning during installation, not enough adhesive, age of the roof, and trapped moisture. Let’s take a look at each of the problems and how they can be fixed.

Blisters and Bubbles
Blisters and bubbles will form when there are pockets of either air or moisture between the roofing layers or the membrane and roof deck. As time goes on and the sun beats on the roof, these pockets will expand and possibly crack. Once the membrane cracks your roof will take on more moisture creating an even larger problem with your roof.
How To Fix Blisters and Bubbles
There are a few things that you can do when it comes to fixing blisters and bubbles in your flat roof. First, you can cut away to spots that are blistered and bubbled areas and replace them. It is advised that you replace the same number of layers as you removed. The other way of doing this is to cut an “X” into the blister or bubble and peel away the bad parts and replace them, again with the same number of layers as you removed.
Regardless of which way you choose to do this, always overlap at least six inches past the blister and bubble so that you are overlapping the old with the new.
Cracks or Membrane Ruptures (Alligatoring)
Having cracks or membrane ruptures in your flat roof is a sign of aging. Over time, the sun will heat up the membranes on the roof. After a few years the heating and cooling of the roof accompanied by ice and rain contribute to the cracks and ruptures.
How To Fix Cracks Or Membrane Ruptures
The true fix to cracks or membrane ruptures is to apply a brand new coating to your flat roof. Before applying be sure to clean the roof of all debris and particles. The next step is to place a primer down that is compatible with your roof deck. Apply the coating and reinforce the coatings with fiberglass mesh strips. The strips help strengthen the roof and the coating.

Frequently Asked Questions
Q. Why is my roof bubbling?
- A roof may show signs of bubbling when pockets of air or moisture get trapped between the membranes. This can happen when the adhesive is not placed on all of the roof deck.
Q. Will bubbles in the rubber roof go away?
- No. The bubbles in the rubber roof will not go away. They may shrink, but the constant heating and cooling of the roof will cause more problems the longer the bubble remains in the roof and is not repaired.
Q. What are roof blisters?
- Blisters, like bubbles, are when air or moisture get trapped between the membranes of your roof. The sun and the weather can exaggerate the blisters and make them worse over time.
Q. What causes flat roof leaks?
- Flat roof leaks happen when bubbles, blisters, and cracks are not taken care of as soon as possible. The longer these are left untreated the more chances of damage and leaking can occur.
Inspect Your Flat Roof
There are often problems with flat roofs, including bubbles. Bubbles will show up when the original roof was not put in properly or there were problems with the installation. A small problem with your flat roof can become a much larger problem when left alone. For this reason it is a good idea to inspect your flat roof from time to time, preferably twice a year. This will allow you to catch any problems before they become a more serious problem.