How to Prevent Moisture Problems in Resin Flooring
Installing a resin floor can transform a tired concrete surface into a hard-wearing, easy-to-maintain finish. However, even a high-quality resin system can fail if the concrete or screed beneath it has not been properly assessed and prepared.
Moisture is one of the most common causes of flooring problems, but it is not the only barrier to a successful installation. Dust, oil, weak concrete, cracks and an uneven surface can all affect how well the new flooring bonds to the substrate.
Taking time to inspect and prepare the floor before applying a coating can help prevent costly repairs, delays and premature failure.
Why Moisture Matters Before Installing a Resin Floor
Concrete and sand-and-cement screeds can retain moisture long after the surface appears dry. Moisture may also rise through an older slab if there is no effective damp-proof membrane beneath it.
When moisture becomes trapped below a resin coating or another moisture-sensitive floor finish, it can interfere with adhesion. Warning signs may include:
Blistering or bubbling
Peeling or delamination
Discolouration
Damp patches
A cloudy or uneven finish
Failure of the coating to bond properly
The surface may look ready, but appearance alone is not a reliable moisture test.
Test the Floor Before Choosing a Solution
Moisture testing should form part of the initial floor assessment. A suitable moisture meter can identify areas of elevated moisture without relying on guesswork.
Take readings in several locations rather than testing only one convenient spot. Doorways, external walls, repaired sections and areas close to plumbing may behave differently from the rest of the floor.
The acceptable reading depends on the substrate, the test method and the flooring system being installed. Always compare the results with the flooring and damp-proof membrane manufacturers’ technical guidance. If the results are uncertain, ask a flooring specialist for advice before proceeding.
For more information about moisture testing, read ScreedGiant’s guide to eliminating barriers to quality flooring.
Suggested image: A contractor testing a concrete floor with a moisture meter.
Can a Liquid Damp-Proof Membrane Help?
Discovering excess residual moisture does not always mean that the complete slab must be broken out and replaced.
Where the substrate is otherwise sound and the chosen flooring specification permits it, a surface-applied liquid damp-proof membrane can suppress moisture within the concrete or screed. It creates a barrier between the damp substrate and the moisture-sensitive system installed above it.
Depending on the selected product and site conditions, this approach may:
Reduce waiting time before the floor finish is installed
Avoid unnecessary removal of a sound substrate
Lower labour and disposal costs
Help protect the new flooring from residual construction moisture
A liquid DPM is not a substitute for diagnosing an active leak, defective drainage or another continuing source of water. Those problems should be corrected before the flooring system is installed.
ScreedGiant supplies specialist damp-proof membranes and moisture barriers for use with suitable concrete and screed substrates.
Other Barriers to a Successful Floor Finish
Moisture control is only part of the preparation process. Before applying resin or another bonded finish, check the following conditions.
Dust, Oil and Surface Contamination
The floor must be free from dust, grease, oil, paint, curing compounds and other materials that could prevent adhesion. Simply sweeping a heavily contaminated surface may not be enough. Mechanical preparation may be required to expose clean, sound material.
Weak or Laitant Concrete
Laitance is a weak, dusty layer that can form on the surface of concrete or screed. Applying a strong coating over a weak layer does not strengthen the substrate; the coating may detach with the laitance still bonded to its underside.
Remove all friable or unsound material and confirm that the remaining surface is strong enough for the intended flooring system.
Cracks and Damaged Areas
Cracks, holes and broken edges should be investigated before they are repaired. A static crack may require a different treatment from one caused by continuing movement.
Use a compatible repair material and allow it to cure as instructed before covering it. Treating the visible crack without understanding its cause can allow the defect to reappear through the finished floor.
Uneven Surfaces
High spots, hollows and abrupt changes in level can affect the appearance and thickness of a resin coating. They can also cause water to collect in unwanted areas.
Grinding, repairing or applying a suitable smoothing compound may be necessary to produce the required surface profile and level.
A Practical Pre-Installation Checklist
Before installing the floor finish:
Identify the substrate and assess its condition.
Check for leaks, rising damp and other sources of moisture.
Test moisture levels at several representative points.
Compare the readings with the manufacturers’ requirements.
Remove contamination and mechanically prepare the surface where necessary.
Repair cracks, holes and weak areas using compatible products.
Apply the specified primer or damp-proof membrane correctly.
Observe all coverage rates, mixing instructions and curing times.
Confirm that the prepared surface is ready before applying the final system.
Suggested image: A prepared concrete floor divided visually into testing, crack repair and coating stages.
Good Flooring Starts Below the Surface
Many flooring failures begin below the visible finish. A careful inspection, accurate moisture testing and thorough preparation provide a much stronger foundation for a durable result.
If excess moisture is found, do not cover the floor and hope for the best. Establish where the moisture is coming from and choose a compatible solution for the substrate and final floor covering.
For moisture meters, damp-proof membranes, primers and specialist flooring products, visit ScreedGiant.