How Long Can Pool Plaster Be Exposed?

Written by Michael Dean
November 29, 2023

exposed pool plaster and calendar

Draining your pool should normally be a last-resort solution for pool maintenance. It is expensive to refill your pool, and leaving your swimming pool plaster exposed can lead to some problems. Inground pools must be drained and refilled every few years or if there is an urgent repair that requires the pool to be empty. If you need to drain your pool, you may wonder: how long can pool plaster be exposed?

In this article, I will answer this question and other frequently asked questions regarding leaving your pool plaster exposed for too long.

Main Takeaways

  • Do not leave your pool exposed for more than a week; it will be detrimental to your plaster.
  • Refill the pool within a day or two after drainage to avoid long-term damage.
  • Leaving plaster exposed can cause it to crack, peel, loosen or delaminate entirely.
  • It’s best to hire a professional to drain your pool since it is a complicated process.

How Long Can Pool Plaster Be Exposed?

If you have drained your pool, leaving it unfilled for more than a few days would be unwise. But if the situation is unavoidable, your pool plaster can be exposed for approximately a week before serious damage to the pool plaster occurs. Beyond that, you may experience difficulties requiring extensive repair services, which I’ll detail below.

How Soon Should You Refill The Pool After Draining?

Ideally, you should refill your pool the same day it is emptied, within 24 hours. However, if that is not possible, the pool should be refilled within 4-6 days. It’s essential to refill the pool as soon as you can with correctly-treated water and chemicals because you risk permanent damage to your pool due to groundwater pressure under the concrete pushing upwards, also called hydrostatic pressure.

With an inground pool, there is also the possibility of hydrostatic pressure from all sides. The water in the ground around your pool will exert pressure on the walls of your plaster, causing it to crack. The pressure can even damage the foundation of the concrete pool itself.

What Happens If You Leave Your Plaster Exposed For Too Long?

Pool plaster is a common finish for concrete pools. Your pool plaster is usually a coat of waterproof cement specially formulated to remain underwater at all times. For this reason, the plaster should not be exposed for more than a week.

If you leave your plaster exposed for just a few days, you may notice damage to the pool. For example, the plaster may start peeling, blistering, bubbling, cracking, and tiles may loosen because of issues caused by hydrostatic pressure or exposure to harsh UV rays. These damages can even occur after just a day or two, depending on your local climate, the age of your plaster, and its quality. This is why you must refill the pool as soon as possible.

Leaving your pool plaster exposed to natural elements increases the risk of calcium deposits, brown manganese stains, and pool deterioration. There are also unfortunate instances when the entirety of the plaster ‘pops’ off entirely, separating from the concrete and PVC pipes below, also called delamination.

Outside of plaster damage, there are several other risks to leaving your pool empty, which I cover in another article.

Pool Plaster Care Tips

It’s important to care properly for your pool and its plaster, especially if it is new plaster. Here are some of my top tips to keep in mind for pool plaster upkeep.

Refill The Pool Carefully

When you have finished plastering (or replastering) your swimming pool, it is vital to fill it up at a constant pace and not stop until you have reached the desired water level. Doing so is essential to the curing process and will help to avoid cracks and stains in the plastering. It is also best to proceed quickly at this stage and use multiple hoses if possible. The last thing you want is unsightly stains on your new pool plaster!

Brush The Pool

Once the pool is filled, it needs to be brushed. Brushing removes excess plaster dust from the walls of your pool to prevent it from hardening. For best results, use a nylon brush, which is gentle, and brush twice a day for two weeks to aid the curing process. Make sure you brush the floor and steps as well, not just the walls! You should notice a cloudy, dusty substance that will settle at the bottom. Use a vacuum to remove the sediment.

Even after your new pool plaster has cured, you will need to keep a regular brushing schedule to keep your plaster in tip-top shape.

Balance The Chemicals

Your pool plaster is easily affected by the chemical balance of your water. Closely monitor your pool’s pH balance and chlorine levels and ensure they’re at the recommended levels for your pool type.

Filtration Is Important

Your filtration system also plays a part in the upkeep of your pool plaster. If your filtration system is compromised, your water’s pH balance could be affected, or you could be at risk for an algae infestation, which is very challenging to fix and detrimental to your pool plaster.

Watch Out For Problems In Your Plaster

Keep an eye out for the following issues on your plaster: dark blotches and specks, mottling, discoloration, cloudiness, holes in the plaster, or plaster feeling rough. These issues will need to be fixed and are best done as soon as you notice them before the problem worsens. If you’re unsure what to do, consult a pool professional on how to proceed next.

How To Properly Drain The Pool

There’s no way to mince this: the best way to drain a pool properly is to hire a professional. You essentially need to empty around 20,000 gallons of water, which will take 6-8 hours to do safely, and then refill the same amount within 1-2 days.

Depending on where you live, you may also need to form a water disposal plan compliant with your local water authority’s regulations, get a permit, and declare your water safe to be drained. You may need repairs post-drainage as well. Draining is challenging, and there’s a risk of several things going wrong with a DIY drainage and refilling project. So, only do this if you know the risks and how to do it properly. So, if you’d like to learn more, check out my guide on how to drain your pool swimming pool.

Bottom Line

Properly looking after your pool plaster is the best way to ensure its longevity. However, pool plaster can be pretty finicky, so you should really know how to take care of it. Pool plaster is meant to stay underwater, so when you drain your pool, you must refill the pool as soon as you can. Ideally, don’t leave your plaster exposed for more than one week.

If you have any further questions, please feel free to reach out and ask more questions; I’m always happy to help.

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