Spring is a wonderful time of year but, it can bring some pool worries. April showers bring May flowers but they can also cause floating pool liners. Although the main component of a pool is water, vinyl pool liners are at the greatest risk of “floating” when the concentration of ground water around the pool area becomes greater than the volume or body of water inside the pool area cavity. This is where we get the term, “floating liner”.
A floating pool liner can be very unsettling to pool owners who have not witnessed this problem before. There are a few different reason why this problem can happen but the repair process is the same regardless of how it came to be – to fix a floating pool liner, you simply need to get the water out from behind the liner. Before you can get the water out from behind the liner, you first need to understand what went wrong and what would allow this problem in the first place.
Water behind the liner can really only be from one of two sources, which are: water leaking out of the pool, or ground water from the water table of the ground surrounding the pool. This sounds easy enough to determine but unfortunately, it is not always that easy. Ground water can be the source of a floating pool liner even if you have owned your pool for many years and this has never happened before. Ground water tables can change over time as land around your property gets developed. You can also experience events with elevated ground water tables due to heavy rains, snow melt and even extended periods of drought followed by moderate rains; as this changes the speed and ability for the earth to absorb water. The problem does not even necessarily need to be in your immediate area, as there can be a cumulative trickle down effect if conditions are just right.
How would you know what the source of the water under your liner is? The first thing that you need to note is the current water level in your pool. This one factor will very likely be the key to figuring out where the water under your liner is coming from. You should also check the water behind your liner for chlorine with a test strip if you have the ability to test that water specifically. If you have a puddle in your yard, that happens to have 3 parts per million of free chlorine, you can be fairly certain that it came from your pool.
The most common period of the year when the pool is at risk, is from the fall pool closing season through winter into spring, prior to pool opening season when the water level is low. During the fall season, and in through winter and spring, precipitation can be high, thus over time the ground area around the pool becomes saturated; this is when a pool is at risk of developing a floating liner as the water lever is lower than normal operating level. There are however, preventative measures to mitigate the risk of a floating liner.
How To Prevent A Floating Liner
Regular sump pit maintenance is key. The sump well acts as a catch basin that receives water from high water tables and evacuates it away from the pool area. When the water in the sump well becomes full, the pump turns on and empties the well slowly out of a hose and away from the pool. A standard submersible pump can be used for the sump well however, this involves constant manual involvement with monitoring the well and manually turning the pump on and off as needed. The benefit of a submersible pump, with an auto shut off ballast float, is that it turns itself on as water levels in the well rise; and will then shut itself off as the well empties. The sump well’s main purpose is to gather water from around the pool area and direct it away from this area of the property thus mitigating any risk of liner float due to ground water intrusion. If your pool does not have a sump pit, consider adding one at your next pool renovation/liner change.
Pools with traditional tarp winter covers, or vinyl lock in winter covers, are also at greater risk of having a floating liner during the period leading into pool opening season as the covers have plenty of rain and snow melt water from the fall and winter seasons pumped off. The water on top of these covers should be left on, and not drained off, until the area around the pool is drier or when the area around the pool is kept manually drier with the aid of the sump well maintenance mentioned above. The water sitting on top of these covers adds water volume into the pool cavity area and, combined with the lower pool water underneath, functions to equalize the total water inside the pool area in relation to the surrounding concentrations of ground water around the pool. As previously mentioned, the pool is at greatest risk of liner float when the water volume inside the pool is lower, and the concentration of water outside the pool area is higher. Therefore, by timing the pumping-off of your winter cover for opening during a dry period, or after routine sump well maintenance, you will prevent the risk of developing a floating liner. Your Aqua-Tech team always recommends filling the pool UNDER the winter cover until it looks like the pool is just about to overflow before draining water off the top of your cover.
Safety covers offer benefits to mitigate floating liners. Aside from keeping the pool safe and protecting your investment, safety covers are the ideal winter cover to help mitigate the risk of a floating liner when working with routine sump well maintenance. Safety covers are designed to keep debris and objects from getting into the pool but, their material design allows for rain and snow/ice melt to diffuse through the cover and into the pool. Therefore, by naturally filling the pool via mother nature over the course of the fall and winter season (during seasons with high precipitation) the pool will fill right back up to the pool’s normal operating level. This free fill from mother nature saves water and money in the spring and you won’t have to top your pool back up with your garden hose! A full pool under the cover going into spring time, as mentioned above, ensures that the water volume inside the pool cavity is at its highest and will equalize with outside ground water; preventing a floating liner.
Is your pool liner floating now? Please reach out to www.findmyanswers.ca and our technical solutions team will be there to help!