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Marblesheen pool resurfacing
Marblesheen lifting, sounding hollow or leaching white crust? We repair the failed areas properly and bond a seamless fibreglass and gelcoat membrane over the whole pool, so you never have to patch marblesheen again.
What it is
What is marblesheen?
Marblesheen is a decorative render applied over the concrete shell of a pool. It is a cement-based mix with crushed marble and other fine aggregate, trowelled on to give a smooth, polished, stone-like look. It was the standard finish for concrete pools for many years, and it is often called marble plaster or pool plaster.
Like all cement-based finishes, marblesheen is porous. Pool water slowly works on it from the day the pool is filled. Over the years the surface weathers, roughens, stains and eventually starts to come away from the concrete.
Signs it's failing
How marblesheen breaks down
White crust leaching out
The first sign is usually calcium bleeding out of the surface. It hardens into white, salty-looking runs and lumps that look like they're flowing, but are rock hard. It means water is getting into or behind the marblesheen.
Water gets behind the render
Once water is behind the marblesheen, it pushes the render away from the concrete. The bond is lost, even where the surface still looks intact.
Sections start lifting
Areas of marblesheen crack, lift and fall away, leaving rough patches and exposed render underneath.
Drummy areas when the pool is empty
When we drain the pool and it dries out, tapping the surface finds hollow, drummy areas. These have already let go of the concrete and will keep failing.
Why not patch it
Why patching marblesheen doesn't work
The old marblesheen in your pool has weathered. New marblesheen trowelled into a patch never matches it, so the pool ends up with a blotchy, spotty finish. It is the same problem as trying to patch an old gelcoat: you can't match a surface the water has been working on for years.
A patch also does nothing for the rest of the pool. The surrounding marblesheen is just as porous and just as old, and it keeps breaking down around the repair.
Our system
How we resurface a marblesheen pool
- We drain and protect the pool and let the surface dry.
- We tap the whole pool and remove every loose and drummy area back to sound material.
- We re-render those patches so they sit level with the surrounding surface, then grind and wash the whole pool to give a sound bonding profile.
- We laminate the pool in fibreglass matting with vinylester resin, followed by a vinylester base coat.
- We finish with a UV-stabilised gelcoat in your chosen colour.
The patches don't need to match, because they're covered. You end up with one seamless, even surface across the whole pool.
The difference
The gelcoat is the working layer
Marblesheen sits in direct contact with the pool water, and the water slowly works its way into it. With our system, the gelcoat is the surface that meets the water. It gives you the colour and the smooth finish, and it is also the barrier between the water and the fibreglass underneath.
The fibreglass never touches the pool water. That's why the new surface stays smooth, resists staining and gives black spot nothing to grow into.
Questions
Common questions
Can you patch my marblesheen with new marblesheen?
We don't recommend it. Old marblesheen has weathered, so new marblesheen never matches. You end up with a patchy, spotty finish, and the water keeps working on the old surface around the patch.
What is the white crusty build-up coming out of my pool surface?
It is usually calcium leaching out of the cement render. Water gets into or behind the marblesheen and carries calcium out through cracks and weak spots, where it hardens into white, crusty runs or lumps. It is often the first sign that the marblesheen is starting to fail.
What does drummy mean?
A drummy area is where the render has come away from the concrete behind it. When the pool is empty and dry, tapping it gives a hollow, drum-like sound. Those areas have to be removed before any new surface goes on.
Do I need to remove all the marblesheen first?
No. Sound marblesheen stays in place as the base. We remove the loose and drummy areas, re-render them level and prepare the whole surface before the fibreglass goes on.
How long does it take?
Most residential pools take about a week on site, weather permitting. Pools with a lot of drummy marblesheen can take longer, and we'll tell you at inspection.
