Why Has My New Floor Coating or Screed Failed to Stick?
Many people aim to re-coat their floors, often because the existing coating is flaking, bubbling, or lifting. In some cases, the current layer may still be well-adhered but has become worn and tired over time.
A common mistake is simply over-coating the existing surface, expecting it to look fresh, bright, and ready for use. Unfortunately, this approach often results in the paint lifting off the floor during the first use.
The usual next step is to contact the manufacturer and assume the issue lies with a faulty batch of paint. However, it is extremely unlikely that the paint itself is to blame.
Below are some simple checks that can help identify the real cause of the problem. Take a piece of the failing coating or delaminating screed, peel it off the floor, turn it over, and examine the back closely.
Many people aim to re-coat their floors, often because the existing coating is flaking, bubbling, or lifting. In some cases, the current layer may still be well-adhered but has become worn and tired over time.
A common mistake is simply over-coating the existing surface, expecting it to look fresh, bright, and ready for use. Unfortunately, this approach often results in the paint lifting off the floor during the first use.
The usual next step is to contact the manufacturer and assume the issue lies with a faulty batch of paint. However, it is extremely unlikely that the paint itself is to blame.
Below are some simple checks that can help identify the real cause of the problem. Take a piece of the failing coating or delaminating screed, peel it off the floor, turn it over, and examine the back closely.
What to Look For
- Clean Peel:
The sample piece peels off easily, and the back is completely free of any trace of the existing substrate.
This suggests that the substrate may have been sealed previously — for example, with a surface hardener or silicone sealer — preventing the new coating from penetrating the surface.
- Residue or Dust Present:
The back of the sample shows the old paint, a fine layer of dust, or even pieces of concrete.
This indicates that the new paint adhered well to the existing coating, but the existing coating had already delaminated from the substrate. The presence of dust or concrete fragments also suggests that the surface was not prepared properly, or that the concrete itself is breaking up.
If any of these signs are present, an alternative method must be adopted before applying any new coating or screed.
- Clean Peel:
The sample piece peels off easily, and the back is completely free of any trace of the existing substrate.
This suggests that the substrate may have been sealed previously — for example, with a surface hardener or silicone sealer — preventing the new coating from penetrating the surface. - Residue or Dust Present:
The back of the sample shows the old paint, a fine layer of dust, or even pieces of concrete.
This indicates that the new paint adhered well to the existing coating, but the existing coating had already delaminated from the substrate. The presence of dust or concrete fragments also suggests that the surface was not prepared properly, or that the concrete itself is breaking up.
If any of these signs are present, an alternative method must be adopted before applying any new coating or screed.
The Importance of Correct Surface Preparation
Oils, waxes, or chemicals previously present on the substrate may appear on the back of the peeled sample or be visible on the concrete surface itself.
If rising damp is present, the area from which the coating has peeled will appear darker than the surrounding exposed concrete. This is because the open areas have been exposed to the atmosphere, allowing any dampness to evaporate.
Oils, waxes, or chemicals previously present on the substrate may appear on the back of the peeled sample or be visible on the concrete surface itself.
If rising damp is present, the area from which the coating has peeled will appear darker than the surrounding exposed concrete. This is because the open areas have been exposed to the atmosphere, allowing any dampness to evaporate.
Need More Advice on Surface Preparation?
A technical team are available to provide practical advice and support. Give us a call on 01234 846 780 or email uksales@polycote.com.
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