Re-marbelite versus fibreglass relining
When an older concrete pool needs a new surface, most Cape Town owners choose between a fresh coat of marbelite and a fibreglass lining. Here is how they compare.
What each finish is
Marbelite is a plaster made of white cement and crushed marble, sometimes with colour added. It is trowelled onto the shell by hand and cures into a hard, slightly textured surface. It has been the standard finish on Cape Town concrete and gunite pools for decades.
Fibreglass relining builds a new skin over the existing shell from layers of glass-fibre matting and resin, finished with a gel coat. It turns a concrete pool into one with a fibreglass surface, without replacing the shell.
Look and feel
Marbelite gives the classic soft-white or pastel look, with the water taking on a natural blue. It is slightly rough underfoot. Fibreglass is smooth and glossy, comes in several colours, and feels slippery-smooth to the touch. Some people love the smoothness; others prefer the grip and look of marbelite. Feel both before you decide, if you can.
Preparation
For re-marbelite, the old surface is usually chipped or ground back to sound material, loose areas are removed and cracks are cut out and repaired. The new layer bonds to that prepared base.
For fibreglass, the surface also has to be sound, clean and dry enough for the resin to bond. Loose plaster comes off, and cracks are repaired. Fibreglass can bridge fine surface cracks, but a crack that is still moving, from ground movement or a leak, needs its cause dealt with first or it can show through.
Either way, the pool has to be drained. Where groundwater is high, in low-lying coastal suburbs or after heavy winter rain on the wetter side of the mountain, the contractor should plan the drain carefully. See pool resurfacing and relining for the process.
Care and chemicals
Marbelite is porous. It relies on balanced water: water that is aggressive (low pH or low calcium) slowly etches it, and water that is scaling leaves deposits. Brushing is essential, especially in the first weeks after a new coat, when the surface releases dust as it cures.
Fibreglass is non-porous, so algae has less to grip and many owners find they use fewer chemicals and brush less. It still needs balanced water; very unbalanced water can stain or dull the gel coat.
Under big trees, as in many Southern Suburbs gardens, leaf stains are harder to remove from marbelite than from fibreglass. That is one reason relining is popular there. See pool renovations in Claremont and Constantia.
How long each lasts
Both finishes last many years when they are applied well and looked after. The life of a marbelite surface depends heavily on water balance and use. A fibreglass lining depends on good preparation and bonding. Ask the contractor what life they expect for their product on your pool, what guarantee they give, and what would void it. We do not publish lifespans or prices; contractors must confirm these.
Cost factors
- Pool surface area, including steps and benches.
- How much of the old surface must be removed.
- Crack and fitting repairs.
- The product and number of layers or coats.
- Waterline tiles and coping, if replaced together.
- Draining, groundwater management and refilling.
Which should you choose?
Re-marbelite suits owners who like the classic look and are happy to keep the water carefully balanced. Fibreglass suits owners who want a smooth surface that is easier to keep clean, particularly under trees, and are prepared for a higher upfront cost in many cases. On a shell with structural problems, neither is a cure; fix the structure first. Older pools in suburbs such as Rondebosch face this choice often.
Frequently asked questions
Can I go back to marbelite after fibreglass?
It is possible, but the fibreglass usually has to be removed first. Ask the contractor about the work involved.
Will relining fix my leak?
Not reliably. Find and fix leaks at fittings and pipes first, then reline.
How soon can I swim after resurfacing?
It depends on the product and curing. The contractor will tell you when to fill, when to add chemicals and when to swim.