Replacing a Liner – How a Pool Professional Does it

before liner replacement

I was recently asked how easy it is to replace a vinyl liner for an in ground pool by yourself.  I replied the best I could given the amount of space I was allotted for my reply.  I feel as though if given more space I could give a little more detail about the subject so replacing a vinyl liner will be the topic of this post.  This way I will have the ability to better explain things and maybe cover a bit more than I was able to in my reply.

In the past I have written posts about how to maintain your vinyl liner, and when to change out the liner, but I have yet to write about how to replace the liner.  First of all I want to say that replacing a liner is not necessarily the easiest thing to do, especially if it is your first time doing it.  For this type of project I would recommend hiring a pool professional to do it.  The liner itself is fairly delicate and represents a significant investment.  In addition to that this is probably the most important element of your swimming pool.  Most pool professionals will guarantee their work and take responsibility for any damage that may occur to the liner.  If you were to do it yourself and damage the liner than you will have toe either purchase a new liner depending on the extent of the damage or live with a leaky liner in your pool.  So how does a pool professional replace a vinyl liner in an in ground swimming pool?

I am going to go about this as if you are someone who has absolutely no idea of how this process works.  That being said some of the things I mention might seem like common sense and completely obvious, and I am certainly not intending to insult your intelligence or talk down to you.  I am just going to go through it step by step.

Step 1

Drain the pool – All of the water needs to be removed from the pool before you can remove the old liner.  You will also want to make sure you turn off your equipment.  You don’t want your pump to kick on without any water in the pool.  That would be bad, and could damage the pump and other components of the equipment.


Step 2
Remove the old liner – For this step most pool professionals will cut the liner into sections.  This will make it easier to handle and at this point there is no need to try and salvage the old liner.  I know that some pool owners might want to keep it for some reason.  I had one customer ask to keep it to make a “slip and slide” for their kids.  This is not typically a problem, but I will caution you that if it is an older liner then it will likely be somewhat brittle and may have very sharp edges.  I have been cut by a liner in the past and it is equivalent to a bad paper cut.  Also while removing the liner they will be careful as they move around in the pool.  At this time the liner will be fairly slick, and even the bottom under the liner will be likely be very slick.  At this point they will likely remove all the fittings and light in the pool being careful not to lose any screws.

Step 3
Pressure test the lines – Depending on the company and if there are a couple workers on site they might do this at the same time as the liner is being removed.  This step is especially important if the pool is fairly old and had gone through a few winters.  Pressure testing the lines will reveal if any of them have a leak.  With the liner already out of the pool, this is an ideal time to check the lines as any repairs needed will be easier to make without a liner in the pool.


Step 4
Clean up the bottom – There will likely be some algae and small debris on the bottom that will need to be removed.  For this step a hose or broom will work well.  They will also make sure that the hose pressure is not too high while doing this.  High pressure can damage the bottom and require more work to repair.  Usually at this time, if there are a couple workers on the job, one of them will be running the hose while the other is removing the water from the deep end.  Depending on the condition of the pool this step can be rather off putting.  I have replaced liners in the past where the owner had just moved in and the previous owner didn’t take care of the pool.  If that is the case you might find some dead creatures in the water and have to remove them.  Not my favorite part especially if you are standing in the water with them.

Here you can see the dark areas where repairs have been made

Step 5
Access and repair the bottom – Most pool bottoms are made of one of two mixtures, either vermiculite and cement or sand and cement.  Either way repairs may need to be made.  In most cases after removing the liner ground water will start to seep into the pool.  This is normal and something that will have to be dealt with.  Typically there is groundwater around the pool all the time but goes unnoticed until the liner is removed, this is because the weight of the water in the pool holds the ground water back, but sometimes in the corners of the pool the ground water can come up through the mix and “wash out” the bottom in that area.  This is where repairs will need to be made.  In some cases, with older pools when your remove the old liner the mix will stick to the bottom of the liner and come up with it when it is removed.  This is another example of when a repair is needed.  This step can be the most time consuming part of the whole process depending on the extent of the repair needed.  I  have seen some pools in which the entire bottom needed to be repaired.  This is unfortunate in that it adds additional costs to the project and the repairs may need to wait until the ground water subsides enough to make them.  Sometimes if the groundwater is flowing in quick enough any repair made on the bottom will just be washed out.  Typically the ground water will slow down enough or completely stop after enough time passes.  This can take a few days depending on how much water is in the ground around the pool.  Remember that there is commonly water in the ground around the pool and once the old liner comes out it now has a place to flow.  Once it subsides and the repairs are made the new liner can be installed.

Step 6
Install the new liner – Again the bottom needs to be free of any debris before installing the new liner.  Any piece of debris left behind will feel much larger once the liner is over it, and in the hot summer sun it is not much fun to have to crawl underneath a liner to remove a tiny piece of debris.  Now that the bottom is completely free of debris the new liner can go into the pool.  At this point the liner will be unboxed and unfolded.  I find it easier to unfold the liner from the shallow end to the deep end.  Typically the liner will be marked on the backside to distinguish the different parts of the pool.  There will usually be a sticker in the center of the shallow end identifying it as the shallow end.  There will also be markings or stickers identifying where the break points are.  If these are in place as the liner is installed then there will likely be minimal adjustment needed once the liner is completely in the pool.  Once the liner is in place you might see the workers place vacuum hoses behind the liner in the deep and shallow ends.  This will remove all the air behind the liner and cause the liner to suck back into all the nooks and crannies of the pool.  Doing this will allow the workers to be sure that the liner is properly oriented in the pool.

Step 7
Cut in – This is the part of the process that needs to be done with extreme care.  At this point all of the returns, main drains, skimmers, lights, steps, and benches and whatever other features are in the pool will be cut out.  These cuts need to be exact otherwise there is the potential for a leak.  Being that the liner is in the pool the screw holes will not be visible and the workers will rely on their sense of touch to determine where the screw holes are exactly.  Each fitting will be perfectly cut out and step area will be removed.  Once that is finished they can now start filling the pool.

Step 8
Fill the pool – At this point it is time to start the hose or call in the water truck.  Once the pool is full the equipment can be turned on again and you are ready to swim in the next few days, depending on your tolerance to cold water.  You will also want to let your pump run for at least 24 hours and then test the water to find out what chemicals are needed.