MGK Pool Service

Inground Liner Replacement

Inground Liner Replacement Contractor | (978) 710-8667

Most people only have to deal with an inground liner replacement once. The reason is that most people only own their home for 5-9 years, and inground pool liners last about as long.

Estimate/Average Cost – Inground liner replacement usually costs 3-5k for the pool liner and installation work.

Inground Liner Replacement – Choosing The Liner

Inground Liner Replacement Contractor MGK


Your installer should be able to supply you with samples from a few quality manufacturers. You want a liner made from virgin vinyl, not one that uses any recycled materials. Pool liners made with recyclables are less pliable, affecting the durability, and it’s ability to handle seasonal temperature changes.

Before you order a new liner, you will want to decide on any changes to the pool shape. These include the addition of stairs; change in the slope angle, or pool depth. Many homeowners are eliminating deep ends for safety.

Inground pool liners come in a variety of exciting new colors and patterns. There is textured vinyl for better traction on steps covered by the pool liner. You will find all manufacturers offer thicker mils for the walls, pool bottom, or pool steps, depending on your needs. A 27 or 28 mil sidewall is the most common upgrade.

One of the better inground pool liner manufacturers is Latham. They were the first to make floor seams invisible. You can check out their 2018 inground pool liner design catalog here. My favorite design of theirs is the 27 mil Chesapeake-Gemstone pattern.

If you don’t like the faux tile border prints, there are liner options with no border.

Pool Liner Warranties

Most people misunderstand pool liner warranties. They are pro-rated, which means you get less and pay more the more time the liner is in your pool. I would like to point out that in my personal experience with 7 or 8 major manufacturers, and at least 2000 liner installations over a 40-year career, 1 out of 70 liners have a problem during the initial liner installation. 1 out of 700 pool liners will have a failure in the second year. Then just 1 out of 2000 will have a failure in the third year. New high-quality inground pool liners don’t fail often, they may get damaged, but it most likely won’t be due to a manufacturer defect, which is all they cover.

Few if any inground pool liner replacements are credited with a manufacturers defect after the fourth year, so don’t purchase a liner based on a “warranty gimmick”. I would love to hear from pool owners that have successfully used a warranty from a manufacturer. Anyone trying to get a higher price for a job because of warranty is either uninformed or unscrupulous.

Draining Pool Water

When the liner arrives it is time to take the water out of the pool. You may choose to store the water on site or discard it. If you discard it, be sure not to raise your groundwater table, flood your neighbor, or pump into a street or basin not allowed by your town, make good decisions.

Our big concern when we pump out a pool is the height of possible groundwater. When it is higher than the pool bottom, it can cause some damage and extra work.

If you do have a high water table and the pool got installed at a time of the year when the excavator hit water, then you probably have a pipe going into crushed stone under your pool. When this pipe location is known, the groundwater can be pumped down and the potential problem eliminated. Without the pipe, dealing with a high water table can mean extra costs, so be sure to ask your installer how much it will cost to handle this issue.

Inground Pool Walls Collapsing Potential

We installers have all heard stories of pool walls collapsing when a pool is drained. I have only had this happen on a wood-walled pool, but have seen steel walled pools move. If your walls are not perfectly straight, to begin with, then you may not have a cement collar or braces around the outside of your pool wall. If this is a possibility, I will wait till a dry period to relieve the weight of the backfill on your pool walls, I would prepare well and do the job as quickly as possible, and avoid any extended rain forecasts.

Pool Bottom Concerns When Doing an Inground Liner Replacement

I always hope that your pool bottom is vermiculite. Vermiculite is a cement product that can be easily cleaned and patched. If the vermiculite was installed thin or got exposed to a high water table for extended periods, then additional repairs may be necessary.

Older pools may have a sand pool floor/bottom. This will be displaced when the liner is removed and will need to be re-troweled at an additional cost. The other option is to cover it with vermiculite, making a permanent bottom.

Stone Dust Pool Bottom

My least favorite inground pool bottom to work with is stone dust. It works well for the initial installation, but the sharp pieces of stone that make up the stone dust lift up as the smaller pieces settle. The sharp stones adhere to the liner as it’s being pulled out. The removal of the pool liner causes a residual of sharp stone chips that will always cause premature failure of the pool liner.

The only option is to skim coat the pool bottom with vermiculite. If anyone tells you otherwise, you tell them you are going to inspect the bottom for stone particles before you let them put in the new pool liner. Too many people have learned this lesson the hard way.

Grout Pool Bottom

The next most common inground pool bottom is grout. Grout is a sand and cement mix that is formed dry, then carefully moistened and allowed to harden into porous cement. These bottoms usually need some work. At least a quick skim coat to lock down the coarse grains of sand that help make up the aggregate or bond for the cement.

Unless you are positive about your pool bottom type, you need to be aware of the options and know what to expect for possible additional charges. Nobody likes surprises, and I hate to give bad news, but quite often we are not given enough clues to guarantee what your pool bottom is until the pool gets drained.

Inground Liner Replacement Steps – What We Do!

The liner is here, and the pool is empty. We cut the old pool liner into strips and fold it for removal. It’s time to prepare the pool for relining.

  1. All the face plates and gaskets and pull the light from the deck box connection, and remove it.
  2. The walls are inspected for damage or rust through. We can install steel or aluminum plates to repair rotted skimmers and returns.
  3. Every underground pipe is tested to identify any buried plumbing failures.
  4. We visually inspect the light niche, skimmer box, main drain, and stairs sections to find any cracks, gasket failures, or needed repairs.
  5. Your fiberglass or plastic stair section gets cleaned with our unique 2 step process, and the step section is covered with our stair plate to prevent damage.
  6. Steel or aluminum staircase rods are cut out, and the holes get caulked.
  7. Liner track is cleaned and sized to ensure the new liner will stay in place. With extra care around the stair corners.
  8. The entire pool wall is scraped to remove loose dirt, rust, and burs.
  9. Liner track and the pool walls are washed down with a high-pressure nozzle.
  10. Then the liner track is blown out, and the coping caulked to the pool wall. Any wall seam or stair seam gets caulked too. This caulking seals all cracks and gives us a good vacuum when we set the liner. It also helps keep out moisture which causes corrosion.
  11. We apply rust restore to any badly rusted spots, and then put a rust-inhibitive paint.
  12. Pool bottom gets carefully washed and vacuumed to remove all debris. Repeat this step as necessary until completely clean.
  13. Gaskets replaced wherever needed.
  14. Wall foam installed.
  15. The liner set into place and vacuum formed to remove wrinkles.
  16. New stair rods installed when needed.
  17. A set of new face-plates and gaskets installed. We carry an extensive supply of stainless steel screws, so we make sure that all old stripped screws get replaced with the proper stainless screws.
  18. Fill the pool with water
  19. We pick up and remove all trash

Importance Of Measuring The Swimming Pool Well

The swimming pool has to get correctly measured to avoid overstretching the pool liner. Areas of concern include the wall, pool corners, and steps. Then your inground pool has to get properly set in place. These are two of the most critical elements when doing an inground liner replacement.

If your pool liner gets overstretched in any area, it will be thin, susceptible to leaks and premature failure. For your pool liner to fit like a glove, and be free of wrinkles, your pool has to get measured with extreme accuracy. Then it has to be evenly stretched “a little” while it is centered and set.

To be correctly set, you have to get a good even vacuum all the way around. If you have gaps where the pool wall meets the coping, or wall seems that are leaky, your vacuum will be weak, and uneven. Weak suction will result in large air pockets in the corners (bellied corners), seams won’t be close to wall/floor intersections, and the pool liner will be overstretched to compensate.

David Clapp is my primary inground pool liner replacement /installer and wrote most of this article. He has over 40 years experience installing inground pools and liners here in Massachusetts. He enjoys answering questions when he has time. Please ask questions in the comments below. Thank you!


I started off this article by saying most people have to do an inground liner replacement every 5-7 years. But I have seen inground vinyl liners last up to 30 years when a premium pool liner got installed and pool chemicals were balanced well.

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