Have you ever wondered how long you can leave your concrete pool empty? There was a time when the question “how long can I leave my concrete pool empty” was my major worry every time winter came around the corner.
There’s so much conflicting information about how long you can leave your pool empty. Different people have different opinions and experiences, which often leads to confusion, unanswered questions, and bad advice. A lot of this conflicting information also seems to be due to both misunderstanding and misinformation too.
Here’s how long you can leave a concrete pool empty, what can happen if you don’t, and some things to remember if you live in a cold climate.
Should You Completely Empty Your Concrete Pool?
A concrete pool’s design is such that the walls and floor are held in place by high hydrostatic pressure. So when you remove the water from your concrete pool, you’re taking away the water that helps to support and protect your pool liner.
Without this support, the pool walls will start to sag and collapse. So, the longer you leave your concrete pool empty, the more likely damage will occur to the wall structure. Therefore, once you’ve drained your concrete pool, you should refill it as soon as possible.
You should never leave your concrete pool empty for more than two weeks unless you completely replace the liner or repair extensive damage.
Read Related: If I Drain My Pool Will It Collapse?
How Long Can I Leave My Concrete Pool Empty?
Most experts agree that if you’re going on vacation for a few days to a week, then it’s okay to leave the pool empty for that time. Still, if you plan on going away for more extended periods, it’s best to drain it just low enough to avoid potential issues and refill it back to its normal levels when you need to use it again.
That’s because even though concrete pools can generally stay fully drained for as long as necessary, there is always the risk of popping or cracking the wall structure. If this happens, you will have to pay for repairs, which can be very expensive.
Alternatively, if your pool is installed with hydrostatic relief features, you should be able to leave your concrete pool empty for up to 6 months before needing to refill it. Hydrostatic relief valves are typically installed on the bottom of a concrete pool and are designed to let water out through tiny holes to prevent damage to your liner and walls.
What Happens When a Concrete Pool is Left Empty for a Long Time?
Concrete pools can last for decades if they’re properly maintained and kept up to date with repairs and renovations. But if you don’t use your concrete pool for an extended period, it will start to deteriorate over time.
Another thing that happens when you leave your concrete pool empty is that algae start growing on its walls and floor, making them look ugly and unsightly. Algae also consume oxygen from the water, so you cannot use it for swimming anymore, which means more work for you when it comes time to clean up after yourself.
Can I Leave My Concrete Pool Empty in the Winter?
Concrete pools are designed for year-round use, so it’s probably not a good idea if yours is empty during winter. In fact, draining your pool doesn’t mean you can leave it empty all winter long. It just means there isn’t any water and therefore no internal pressure. And that’s not always a good thing.
If you live in a colder area of the country or if it often snows where you live, you might want to consider reducing the water level in your concrete pool now so that it doesn’t freeze over completely during the winter months.
What are the Dangers of Emptying a Concrete Pool During the Winter?
The main danger is that it can crack. Concrete pools are extremely heavy and can weigh up to 50 tons. The concrete pool walls are very thick, but they are still subject to cracking if something happens to them.
If you empty your concrete pool during winter, there’s a chance it will crack because of the weight of the groundwater pressure build-up below. However, leaving the water in the pool will not have any weight and will be fine. Here’s what we mean.
Hydrostatic pressure is simply water pressure that builds up in your pool walls. It can occur when water levels are low or if there is a leak. So, when this pressure becomes too high, it can cause damage to your pool walls and flooring.
Another danger is that there might be damage to the interior of your pool. This damage could happen if there were any leaks or cracks in your interior that were hidden by water before you drained it. When no water is in your pool, these leaks become very apparent and may even cause significant damage to your property.
Can an Inground Concrete Pool Collapse if Emptied?
If you think that concrete pools are very sturdy, durable, and can withstand high weathering and erosion levels, you’re right. However, they may be unable to withstand being completely emptied for an extended time.
In fact, leaving a concrete pool empty for more than six months can result in severe structural damage to the surface. That’s because concrete expands when wet and shrinks when dry, which puts pressure on its surface as it dries out again. This pressure can cause cracks on the surface of your pool deck or even lead to deformation of the entire structure if not addressed quickly enough.
You Don’t Have to Swap “Old” Water for “New” Water!
You probably wouldn’t have thought of it, but it’s true. The water in your concrete pool doesn’t have to be drained and replaced before opening in the spring. It is a common misconception that this is necessary because of the chemicals used in the winter.
In fact, when you close your pool down for the season, you should simply lower the water level and backwash your filters to get rid of any debris and dirt that may have collected during the year. That done, you can simply add fresh water and start swimming.
Not sure where to start? Here’s a great video on YouTube about opening a pool to help you out with the process without having to do any swapping.
In the end, each concrete pool is a little different. Some may be safe to leave empty for as long as a couple of months; others, only a week or two. Your best bet is to check with your local concrete pool builder or installer to get the most accurate time frame for your pool itself. But at the end of the day, whether it’s one week or three months, your best bet is to keep water in your pool until you’re ready to use it again!
Read our related pool articles:
- Can I Drain My Saltwater Pool on My Lawn?
- Filling a Pool with a Water Truck (All You Need to Know)
- Can My Neighbor Drain Pool Water into My Yard?
- 10 Best Poolside Chairs
- 9 Ways to Keep Neighbors from Using Your Pool
Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.