Osmotic Blistering – What’s the Cause of Bubbles & Blisters in Epoxy Flooring?

You’ve just had a brand new epoxy flooring installed and it looks fantastic! But wait… what are those small blisters that have suddenly appeared on the surface of your perfectly smooth finish? Osmotic blistering is an all-too-common problem in the flooring installation world and it can ruin the appearance of a once perfect system!

Osmotic blistering solutions from Respol

Fortunately, experts at RESPOL have years of experience preparing and installing epoxy resin flooring systems and avoiding common pitfalls that could potentially ruin your investment. The last thing you want after spending time and money on a new epoxy or polyurethane coating is for bubbles or blisters to appear a few weeks after the process is complete. Although it cannot always be avoided, considering the risk of damage by osmosis is important during the initial site survey and substrate preparation. Professionals at RESPOL will always actively work to prevent blisters or bubbles from forming through careful preparation and application.

So, what causes flooring blisters?

The main issue an installer needs to consider when applying any epoxy floor coatings is moisture. Water can have a profound influence in the formation of these chicken pox-like blisters. Osmosis can be defined as the movement of a solvent from a less concentrated solution to a more concentrated one. This movement occurs through a semi-permeable membrane.

When this occurs in flooring, moisture can move up from the concrete surface, through the substrate and push underneath the cured resin. This is what causes the osmotic blistering. It can take a while for this pressure to build up, that’s why blistering does not occur straight away but may take weeks.

What about epoxy bubbles?

Often mistaken as osmotic blistering, little air bubbles can sometimes form on the surface of a resin coated floor. Bubbling is often not associated with water or moisture, rather it is usually connected to an environmental or substrate issue. Epoxy bubbles can occur during the drying process. Example issues include too much air in the resin mix, flooring that is too porous for the applied resin, external temperatures that affect application, or uneven curing – perhaps from thick layers.

To summarise, blistering occurs due to increased pressure from moisture underneath a coating whereas bubbling occurs as a result of gas and vapour within the system.

Preventative techniques

RESPOL are committed to providing a professional, expert service that draws on our 30 years plus of experience in the industry to prevent instances of bubbling or osmosis.

Some of the preventative steps we take to ensure your flooring looks and performs how it should are:

  • Correct surface preparation
  • Ensuring the right materials are selected for the substrate
  • Measuring the moisture content of the substrate
  • Ensuring resin coating is mixed proportionately and applied evenly
  • Selecting a system that is water vapour permeable, if flooring is deemed at risk of blistering

Need a flooring professional?

Even if you have been unfortunate enough to be affected by blisters and bubbles in your flooring, do not despair. RESPOL can survey your current flooring system and offer advice on how to repair any issues and get it looking fantastic again.

All of our installers and fitters are specially trained in-house to ensure the best standards are always met. We guarantee not to use sub-contractors who may not be aware of the complexities surrounding epoxy flooring installation. If you’re looking for a high performing, long-lasting and aesthetically pleasing industrial flooring solution, give RESPOL a call today on +44 (0)1952 740400 or fill out our contact form here.

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