When a pool coating blisters, peels or delaminates, the coating product is rarely the real cause. The preparation that came before it usually is. A coating applied over a contaminated, unstable or poorly prepared surface has little to hold onto. Knowing what proper surface prep involves, and why rushing it creates problems that cost more to fix than the original job, helps any Perth pool owner ask better questions before work begins.
Why does surface preparation matter so much for pool coatings?
Because a pool coating cannot bond to a surface it cannot grip. Pool coatings are immersed in water continuously, exposed to pool chemicals, and subject to sun and temperature changes through Perth summers and winters. Those are demanding conditions for any coating system, and the bond between the new finish and the concrete underneath is what holds it all together. If that bond is compromised by contamination, loose material or a surface that was never properly profiled, the coating is likely to fail early, regardless of the product used or the number of coats applied.
The practical consequence is that poor preparation tends to add to the eventual cost. The failing coating has to be removed, the surface has to be properly prepared anyway, and then the coating has to be applied again. Doing it properly the first time is usually the cheaper path.
What does surface preparation actually involve?
The exact process depends on the condition of the existing surface and any coating already present, but preparation for a concrete pool recoat typically covers several distinct stages, each with a purpose.
Cleaning. Pool surfaces accumulate algae, mineral deposits, scale and chemical residue over time. These contaminants can prevent adhesion even where the concrete underneath is sound. Thorough cleaning removes that surface layer before any mechanical work begins.
Removing loose or deteriorated coating. Existing coating that is flaking, blistering or delaminating cannot simply be painted over. The new system will follow the old one off the surface. Unstable material needs to come off, so the new coating is applied to something stable.
Repairing surface defects. Minor surface defects are addressed before finishing products go on. Leaving them in place creates weak points where moisture can work its way under the new coating.
Sanding or grinding affected areas. Mechanical profiling creates a texture that the coating can key into. Smooth or glazed concrete generally does not give enough grip for a product that will spend its life submerged. Grinding is also a specialty of its own, and the floor grinding and surface preparation service shows the kind of preparation work Recommended Painters WA carries out.
Priming and undercoating. Where required, suitable primers or undercoats are applied to the prepared surface before the finishing system. The primer is chosen for compatibility with both the substrate and the topcoat.
The aim of all of this is a clean, stable surface that is genuinely ready to accept the coating, rather than one that merely looks ready from a distance.
The hidden problem: coating over an unstable surface
One of the most common reasons pool recoats fail early is that new product is applied over existing coating that looked stable but was not. Coating that has lost adhesion can appear flat and intact until moisture gets behind it, and then it lifts. An assessment before work begins should identify areas where the existing finish is no longer firmly bonded, because those areas need to be removed, not painted over.
This is also why the condition of the concrete matters, not just the coating on top of it. If the concrete has deteriorated or needs more extensive repair, recoating alone will not solve the problem. A thorough inspection should separate surfaces that are ready for recoating from those that need resurfacing or repair first. For a side by side look at the two approaches, the guide on recoating a concrete pool in Perth explains how coating differs from resurfacing.
Coating compatibility: why prep and product selection go together
Surface preparation and coating selection are not independent decisions. The coating system must be compatible with the prepared surface, any existing finish that remains, and the conditions the pool operates in. Different primers, undercoats and topcoats are made for different situations, and applying a product over the wrong substrate or an incompatible primer creates adhesion problems even on a well prepared surface.
Sequencing matters too. Coating systems are generally applied in a set order, with suitable curing time between coats, so each layer bonds to the one below it. Rushing intermediate stages to reduce downtime is a common shortcut that can shorten the life of the finished system.
The coating chosen should also be suitable for ongoing water immersion and the normal chemical conditions found in a swimming pool.
What to look for when getting quotes for pool recoating in Perth
A quote that does not describe the preparation in any detail is worth questioning. Preparation shapes the outcome as much as the coating product does, and a low quote that skips preparation stages is not a saving. It is a deferred cost.
Questions worth asking any provider include:
- Will the pool surface be assessed before the scope of preparation is confirmed?
- How will loose or delaminating coating be identified and removed?
- What process is used to profile the concrete before coating is applied?
- How are surface defects treated before the finishing system goes on?
- Which primer system is being used, and is it compatible with the topcoat and the existing surface?
A contractor who can answer those questions specifically, rather than generically, understands why each step exists.
How Recommended Painters WA approaches pool surface preparation
Before recommending a coating system, we assess the condition of the existing pool surface and identify the preparation required. The assessment looks at the existing surface, the previous coating, visible deterioration and any areas that may require additional preparation before the scope of work is confirmed. Cleaning, repairs, surface preparation and compatible coating products are then planned according to the condition of the pool and the scope of work involved.
The aim is a sound surface for the new coating, rather than applying material over areas that are already unstable or deteriorating. For more on the service and its process, see our swimming pool coatings service for Perth pools.
With more than 25 years of experience, Recommended Painters WA works across Perth, including Kewdale and Victoria Park. To discuss your pool and request a free quote, call 0412 691 750 or email karlos@paintperth.com.
Frequently asked questions
Can a pool coating be applied directly over the existing finish?
Only if the existing finish is fully stable, compatible with the new system and has been properly cleaned. In most recoating situations, some removal of deteriorated or delaminated material is required. Applying new coating over unstable existing coating is one of the most reliable ways to produce a finish that fails early.
What happens if surface defects in the concrete are not repaired before coating?
Defects left unrepaired can become pathways for water to get under the coating. Once moisture gets behind the film, the coating can lift and the problem can spread. Minor repairs completed before the coating goes on are generally far less disruptive than dealing with delamination afterwards.
Does the type of pool water affect which coating is used?
Yes. The coating system should be suitable for ongoing water immersion and the normal chemical conditions found in a swimming pool, and the primer and topcoat should be compatible with each other and with the prepared surface.
How do I know whether my pool needs recoating or resurfacing?
Recoating is generally appropriate where the concrete and existing coating are stable enough to be prepared and accept a new system. Where deterioration is more extensive or the surface needs broader renewal, resurfacing may be more appropriate. A proper assessment of the surface should determine which option applies before any work is scoped or quoted.
When can I get in touch to talk about my pool?
Recommended Painters WA lists its business hours as Monday to Sunday, 7:00am to 5:00pm. You can call 0412 691 750, email karlos@paintperth.com or use the contact page to ask for a free quote.
Related pages
This article draws on the following pages.