What are the disadvantages of polyurea?

Polyurea costs more to buy than paint, a liner or epoxy pool paint. That is not a small difference and we do not talk it away. Anyone who looks only at the figure on the quote rarely chooses polyurea, and that is a fair outcome of a fair comparison.

It helps to know where the money goes. Most of the work is not the material itself but the preparation of the substrate: removing what is loose, repairing, levelling, drying and measuring. Then come three layers, each with its own job: a primer that matches your substrate, the sprayed membrane and the aliphatic top coat. Spraying requires heated high-pressure equipment and people who know how to work with it. So you are mainly paying for care and craftsmanship, not for a bucket of product.

We deliberately do not quote a figure here, because every pool and every roof is different. After one visit on site you receive a quote within 24 hours that explains what will be done and why. We compete on value, not on the lowest price. If another solution suits your situation or your budget better, we say so during the visit, even if that means you order nothing from us.

With a liner or a coat of paint you can often still see and correct poor workmanship. With polyurea you cannot. The two components are heated and mixed under high pressure in the spray gun; within seconds the material is a closed skin. A mistake in the preparation then sits beneath a layer that looks perfectly fine from the outside. The result stands or falls with what happens before the machine is switched on, and that makes you dependent on the applicator.

You can reduce that drawback by looking closely at who you bring in. A serious applicator measures the moisture in the substrate and does not spray until the readings are right. He chooses the primer per substrate, because concrete, render, existing gresite and polyester each need a different bond. He works with an aliphatic top coat and can explain why. And he hands over the job with a guarantee certificate and maintenance instructions, so you know what is covered and what you need to do yourself.

Also simply ask how the equipment works and how long the team has been working with it. Anyone who cannot explain that readily does not know the material well enough. How the spray gun works and how to recognise a good applicator is covered in more detail in our article on what polyurea is.

Spraying an average pool takes one day, but the work does not begin and end there. A complete pool renovation takes 5 to 10 working days: draining, removing what is loose, repairing, drying, priming, spraying and finishing. After that you wait seven days before filling, so the top coat can cure fully. All in all you are without your pool for two to three weeks.

The weather also decides the day. Polyurea is not sprayed onto a wet substrate or ahead of a poor forecast, and the primer needs dry conditions. The dates we agree are therefore target dates. We usually meet them, but we would rather move a day than apply a layer onto a substrate that is not yet dry.

For a flat roof or terrace the drawback is smaller: that work takes a few days and the surface can be walked on within a few hours. For a pool our tip is simple: plan the renovation outside the swimming season. In autumn or winter you do not miss the pool, and the work is often easier to schedule as well.

A bare polyurea membrane is strong and waterproof, but not colour-fast in the sun. That is why the aliphatic, UV-stable top coat is not an option with us but a fixed step. The drawback is that you therefore always need that third layer, and that this layer does not stay the same forever.

We give a 5-year guarantee on the UV colour stability of the top coat. Beyond that, every exterior layer under the Spanish sun slowly changes. A gradual change in sheen is normal and not a defect: a satin pool becomes somewhat more matt over the years and the colour too changes very gradually. We would rather name that honestly now than have it turn into a disappointment later.

The good news is that the top coat and the membrane are two separate layers. In many cases the top coat can be renewed after years without replacing the membrane. How that applies to your pool we assess on site. What is not possible: quickly freshening up a faded pool with a coat of paint from a bucket; that is not part of our system and we do not do it.

Polyurea stretches to several times its own length and bridges cracks. That sounds like a miracle cure, but it is a layer, not a structure. A shell that sinks, cracks or moves beyond the elastic limit does not become stable through a coating. A structural repair has to come first, otherwise we are coating a problem instead of solving it.

There are two more limits. Polyurea does not hold back water pressure from outside: groundwater pushing against the back of the shell will push any coating off. And it does not protect against moisture from a wet substrate. The primer absorbs the normal residual moisture of a dried and measured substrate, but no primer helps against a substrate that is genuinely wet. Waiting and measuring is the only thing that works then.

A leak in a pipe also remains a leak. The coating seals the shell, not the pipework behind it. That is why we offer a pressure test of the pipework as standard with every pool, carried out by a specialised company, so you do not discover after the renovation that the water is escaping elsewhere. Sometimes the outcome of the visit is that we first advise something else: a pipe repair, a structural fix or simply waiting until the shell is dry. Better that advice beforehand than a coating that hides a problem.

Polyurea is tough but not indestructible. Sharp objects dragged across the floor, a pressure washer used above the recommended values, or an intervention by a third party (a plumber replacing an inlet without consulting us) can damage the skin. Because the surface is smooth and seamless, such a spot stands out.

Repair is possible, but it is not a job for a Saturday afternoon. The material comes out of a spray rig, not a tube, and a repair needs the same care for adhesion as the original work. We therefore always assess damage on site and then tell you what is possible. Be prepared for a repaired spot to differ slightly in sheen or colour from its surroundings, especially on a top coat that has already spent a few years in the sun.

Mechanical damage, pressure washing above the recommended values and interventions by third parties without written consent fall outside the guarantee. That is not small print to discourage you, but a reason to call first when in doubt, before anyone works on the pool.

A coated pool is easy to keep clean, but it does not forgive everything. The most important rule: chlorine tablets, chlorine granules and other concentrated products never go directly onto the coating and are never thrown loose into the pool, not even while filling. Always via the skimmer basket, a floating dispenser or a dosing system. A tablet left lying on the floor dissolves the top coat locally and leaves a round grey or matt patch. That damage falls outside the guarantee.

The water balance matters too. Keep the pH between 7.2 and 7.6 and the free chlorine between one and three milligrams per litre. A pH that sits too low for weeks takes the sheen off the top coat. Salt water is no problem, but an electrolysis cell gradually raises the pH, so in a salt pool correcting it is the most common task. Do not leave the pool empty in full sun, and do not leave it empty over winter either.

What results from neglected maintenance falls outside the guarantee: attack by incorrect water values or aggressive products, patches from tablets or granules, and algae or mould growth due to poor upkeep. How to clean and which products are compatible is explained in detail in our article on maintaining a polyurea pool. What you as the owner control yourself is set out below.

Polyurea gives a closed, seamless surface without joints. If you love the classic pattern of mosaic, a coating will not bring it back. There is no pattern, no tile grid, no glinting gresite. For many people that is precisely the appeal; for others it is a genuine drawback, and you are entitled to feel that way.

There are limits within the sleek look too. The colour sits in the top coat and you choose it from our range, matt or satin. Anti-slip is mixed through the top coat during application and cannot be added afterwards, so the choice for steps and shallow zones is made in advance. Changing a colour later means renewing the top coat, not a quick repaint.

If you do want tiles, there is an honest middle way: polyurea as a waterproof layer beneath new tiles. You then get the classic look with a seamless waterproof base underneath. If you choose a coated shell, remember that the colour of the shell determines the colour of the water; which shade gives which water you can read in our article on polyurea colours.

Eight drawbacks in a row looks like a lot, and that is the point of this article. A drawback remains a drawback, even when we have an answer to it. The table below sets them side by side, so you can see at a glance what each point means for you and what we do about it.

So who is polyurea not the right choice for? For anyone looking for a quick, cheap refresh for one or two seasons, for anyone who finds a mosaic look indispensable and does not want tiles on a coated base, and for anyone whose pool has a structural problem that must be dealt with first. In those cases we say so during the visit.

Polyurea does suit anyone who wants a leaking or worn pool, roof or terrace done properly in one go and is prepared to accept the preparation, the waiting time and the maintenance that come with it. Those who look at it that way get a seamless surface without joints, a 10-year guarantee on waterproofing and adhesion, a certificate with clear instructions, and a company that comes back after the first season cycle to check that everything is doing what it should.