Do you automatically adjust the “shrink factor” on your pool liners during the colder months so that I get a full cut liner with less stretch? If not, can I request a “winter cut”?

When we make a pool liner, we create a drawing that shows the dimensions of your swimming pool.  In the design process, we reduce certain dimensions to provide for just enough stretch so that the liner will fit without wrinkles, but also without stretching the vinyl too much.

Those of us who make the best liners and who are most confident in our ability to make great fitting liners use minimal shrink factors.  This is why good measurements are so critical and why you should always pay a pool professional to measure your swimming pool.  We do not adjust the length and width so that your liner will have the same perimeter as your pool.  Most of the time we only adjust the depth dimensions by a few inches to provide the proper amount of stretch.  We will also occasionally adjust the slope dimensions as needed.

This is how we make “full cut” liners that fit so well.  We do this year round.  In the old days, some manufacturers would make a “full cut” pool liner only in the cooler months.  In the summertime, they would shrink the dimensions more than normal, maybe even shrinking the length and width.  They knew that the hot summer sun would loosen up the vinyl, kind of like warm butter, and help it stretch into place.

Today, we make a “full cut” liner year-round, even on the hottest summer days.  No adjustments are necessary based on the season.

Can ants or termites attack a vinyl pool liner?

When an inground pool with a liner is leaking, there are only about five things that can be wrong:

1. Your liner may have a split seam.

2. There may be a hole poked or ripped in your liner.

3. There may be a leak in your pipes.

4. There may be a leak in the face plates of the steps, skimmers or return fittings.

5. Your liner may have been attacked by ants or termites.

In trying to find and correct the source of your leak, it’s helpful to look for the most common possibilities first and then to eliminate these possible problems one at a time.  I will try to address each of these problems with a different post over the next few months.  Let’s begin today with the least common of the potential problems: ants or termites attacking your liner.  I have only seen this happen a few times in 30 years.  It makes sense that these bugs, thirsty for water, come up through the ground and chew their way through the liner, causing leaks.  These attacks seem to happen more in arid regions, regions with lots of termite activity, or in periods of drought when insects are desperate for moisture.

I am told that if you look from the backside of the liner, you can actually see the “teeth marks” in the vinyl.  I am also told that you can see the “trails” they leave in the sand or vermiculite floors, much like you would see in an ant farm toy.


* The following article was written by a liner manufacturer:


For many years, it has been known and proven that termites and ants will attack a vinyl pool liner.  It is suspected that the termites are attracted to the pool area due to the dampness around the pool.

Usually, the first signs are very small holes in the liner in the area above the water line.  Quite often, the liner may have dozens of holes in it within a short period of time after they have begun their attack on the liner.

Most of the time, if the liner is taken out of the bead track and pulled away from the wall, you may see the trails that the termites have left behind.  Usually the holes they make in the liner are relatively small, about an eighth of an inch in diameter and are round or oval shaped.

If the pool liner has to be replaced as a result of termites or ants, the homeowner is advised to get an exterminator to treat the ground beneath the liner and around the perimeter of the pool deck.

Here are some of the more likely places for termites and ants to appear:

  • A yard where a tree has been removed
  • A yard where a patio or walkway has been removed
  • Around wooden flower planters
  • Around wooden fences

Although this is not a widespread problem, it should be taken seriously.  An average of ten to fifteen cases a year are reported to us.

Should I be able to see the liner seams in my vinyl pool liner?

We often hear pool owners question whether they should be able to see the seams in their liner.

The answer is yes.  Every liner has seams, at least every six feet, and they are more visible on some patterns than on others.  In the old days, when all patterns were on blue base film, you could not really see the seams since there was less ink coverage.  Today, when most all patterns are on white base film, the seams are more visible, but the less ink there is, the less noticeable they are.

We advise that you wait until the pool is filled before you worry about the seams.  While they are always there, they are much less noticeable under three feet of water.

The liner pictured below (pattern: Robertson) is a good example of visible liner seams on a properly manufactured liner.  The seams on the floor are barely visible.  The vertical seam is razor thin, perfectly straight and the tile is matched almost perfectly at the top.


 Bottom of pool (below):


Pictured below is Morrison, one of our most popular patterns.  If you look closely, you can see two liner seams in the shallow end of the pool.  The Morrison pattern has one of the most visible liner seams out of all of our patterns.  That being said, you will notice that the seams are barely visible, especially if standing 10 feet away and if the pool is filled with water.


In the picture below, you can see a seam across the bottom of an unfilled pool (pattern: McDowell).


Below, we present you with the McDowell pattern again in a pool completely filled with water.  From this viewpoint, it is impossible to notice any liner seams.


Pictured below are two more examples of highly visible liner seams on properly installed pool liners.

liners seams1


Replacement liners vs. New pool liners

Homeowners often ask if there is any difference between a replacement vinyl liner and a liner installed with new pool kits.

There is no difference between a liner that is made as a replacement and a liner that ships with a new pool.  The materials and method of manufacturing are identical.

We make liners every day for both new and existing pools and we never ask the dealer if the order is for a new or existing pool.

As for the thickness of the material, you can order a 20 mil liner or a 27 mil liner for either a new or existing pool.  Both are available; it just depends on the pattern or thickness you choose.  For our comments on which material to choose, read further:  Which liner thickness should you choose?

Can you match a pool liner pattern to a Foxx pool?

We recently had a homeowner ask us the following question:  If given the model number, can you match a pool liner pattern to a Foxx pool?

This is a great question.  We do have standard drawings for Foxx brand pools and we make them every day.  We cannot use the model number, but we can use the drawing number if you have that.  Give us whatever information you have, and we will be happy to locate a drawing if we can.

In the same way, we actually have hundreds of drawings for pools by most manufacturers dating all the way back to the 1960s.  The problem is, how do you know if your pool was built to the plan?  This is especially true with Kidneys, Lazy Ells and Freeform shapes.  The length and width may match, but what about the size of the radius turns?  Even on a rectangle pool, you have to check diagonals to make sure that the pool was built square.

Another problem is that years ago, we made liners by hand, and dealers would routinely over dig the pool to make the liner fit tighter.  Today, with auto-cad technology, we make liners with very little “shrink” factor.  Even if a stock liner fit years ago, that does not necessarily mean that it will fit today.

We often tell our dealers that the fastest way to lose a few thousand dollars is to order a liner per an original drawing without taking your own measurements.  This often entails using the AB method to triangulate the perimeter.

The original drawing can be a good reference tool, but don’t order by it.  If you do, you may be looking at liner wrinkles in your backyard for the next seven years.  Always pay your local pool professional his fee to measure your pool and be responsible for getting you a liner that fits properly.

Why is there a sticky substance on my vinyl liner and how do I get rid of it?

Here’s a question that just came up today.  One of our dealer’s reported that a homeowner’s pool turned green with algae in August, so he added algaecide.  All the algae turned brown and fell to the floor, like it is supposed to, but when he vacuumed it up he had brown stains left in certain areas.  The stains are the same light brown color as the dead algae but appear to be glued to the liner and are rough to the touch.  He tried scrubbing and rubbing, but nothing would remove these stains.  As soon as I saw the photo (see below) it confirmed what I suspected.  Pool Goo or Pool Tar.  I recognized it because the same thing happened to my dad’s pool a few years ago.

The good news is that “pool tar” is not a big problem.  It will resolve itself given time.  As you can read below in a report from a vinyl manufacturer, plasticizer has come out of the vinyl.  It is a sticky, gooey substance that attracts whatever dirt is in the pool and over time, under normal operation, the material is re-absorbed into the vinyl and the stains appear to vanish.  I think it may have taken six months to clear up on my dad’s liner, but it does go away.  I usually hear about this showing up when the pool is opened in the spring.  That makes a lot of sense in that most winterizing kits contain algaecide, and that combined with a high chlorine level seems to create the problem.  Do not try to remove the stain aggressively; this may permanently damage the liner.  Just give it time.




* The following article comes from the Technical Manual of Canadian General-Tower Limited, a manufacturer of the vinyl sheet used to make pool liners.

Sticky Substances on Vinyl Liner commonly referred to as “Pool Tar” or “Pool Goo”

The consensus in the pool industry is that there are several sources of sticky substances, often referred to as “pool goo” or “pool tar” that adhere to and coat portions of the vinyl pool liner.

Some of these sources are:

1.  Algaecide-humate or Quat-humate formed from the interaction of quaternary ammonum compound used in some algaecides and decaying organic material such as leaves, grass, insects, etc.

2.  Interaction of quat algaecides with other substances.  Even chlorine can interact with quats to form sticky material if both chlorine and algaecide exceed the recommended dosage levels.  Quats can easily come in contact with high chlorine levels in automatic chlorinators, resulting in a gummy material gradually being fed into the pool, where it eventually precipitates on the liner.  Many quat containers are labelled with cautionary notes warning against mixing with pool water having high chlorine concentrations.

3.  Chlorinator goo can form when organic material from cosmetics, tanning lotions, etc. are oxidized by high chlorine concentrations resulting in a beige, waxy material.

4.  A light coating of vinyl plasticizer may exude to the surface of newly installed liners during the first idle period of winterization.  This material is clear and only turns dark if contaminated with dirt.  It is attributed to lack of circulation, since it has never been observed in a pool that has been circulated over the winter.  It will almost always re-absorb in two or three weeks if the water is allowed to warm up and is circulated and shocked with chlorine every couple of days.  The problem is not known to occur more than once in the life of a liner and always the first time the pool is re-opened after winterization.

5.  Pool scum is a ring that forms aroudn the pool at the water line and is made up of soil, contaminants from suntan lotion, environmental pollution, and organic materials from bather load, etc.

The following procedure has been recommended by experts in the pool industry as being effective in eliminating “pool goo” or “pool tar” problems.

1.  Stop using quaternary algaecides.

2.  Reduce and maintain pH at 7.0 – 7.2.

3.  Superchlorinate every other day to 6.0 – 8.0 ppm.

4.  Use heater to speed up warming of water, if available.

5.  Continue to circulate water and monitor pressure on filter.

6.  Backwash filter as often as required.


Can I install a vinyl liner in my concrete/gunite pool?

If you own a concrete inground pool and are wondering if it is possible to install a vinyl liner in your pool, the answer is yes, but we don’t suggest it.

Installing a vinyl liner is perhaps the most inexpensive way to fix a leaking concrete inground pool, but converting a beautiful concrete pool into a liner type pool should be the last resort.  We encourage you to repair your concrete pool if you can.

If you decide you must convert your pool, it requires accurately measuring the pool for a liner, installing a bead receiver around the perimeter and then converting the skimmer and other fittings to the liner type that have faceplates and gaskets.

The difficulty of the conversion depends on the internal shape of the pool, whether the contours in the floor are rounded or sharp, and if you have internal steps or other obstacles.

Every job is different so depend on your local pool contractor to advise if your particular installation is a good candidate for a conversion.

Liner wrinkles from rain water

It has rained all season long, your backyard oasis has turned into a pile of mush, and the rain has caused the one thing pool owners don’t want to see – liner wrinkles.

There are two issues here:  how to get rid of the wrinkles, and how to keep this from happening again.

Wrinkles can be caused by ground water, but if the liner looks “pruned,” the wrinkles are most likely due to water absorption. The debate is why did the vinyl absorb water? Is it improper chemical balance or is the material in your particular liner less resistant to absorption than it should be? With a pruned liner, you should always make a warranty claim and see if the manufacturer knows of a any material issue around the time your liner was made, We will talk more about water absorption in another post…

photoDuring periods of heavy rain, if the water level in the ground becomes higher than the water level in the pool, the liner will float.  When the ground water recedes, the liner comes back down.  If there is no vacuum on, the liner will stretch back into place unevenly, creating wrinkles in some areas and a tight stretch in others.  Usually the wrinkles are in the shallow end.

The solution is to drain the water about one foot back down the slope to the deep end, below the floor in the shallow end.  Pull the material back up into place in the shallow end, turn on a vacuum blower (just like during the initial installation) and refill the pool.

There are all kinds of ways to get in trouble here, so this is definitely a job for your pool professional.  If the ground is still saturated with water, the pool walls may collapse under the extra weight.  You may need to wait for drier conditions before attempting to re-seat the liner.  If the liner is more than a few years old, it may be brittle and may rip when you try to get it back in place.  The liner could also tear away from the face plates around the steps and skimmers.

The bottom line:  It is probably a simple and inexpensive fix.  Your contractor just drains some water, re-seats the liner and fills it back up.  Be aware that the liner may fail during the process, but if the liner is more than seven years old, it is about time to replace it anyway.

The second question is how to keep the liner from floating again when you have the next big rain.  You may need to install drains to carry water away from the pool area, or you may want to install a well point and pump to take care of the underground water.  Or you may just decide that this is a once every 10 year event that you can live with.

We have provided several pictures of liners that floated as a result of excess rain water.  You can see the liner wrinkles caused by the floating.


floating liner 1

 floating liner 2

Solid color pool liner walls between the tile and floor

When homeowners visit our website,, they often wonder if the liner pattern pictures they are viewing are true to life of the actual vinyl material.

All of our liners today have the floor pattern coming all the way up the sidewall to the bottom of the tile.  When you look at the pictures of our patterns on our website or on our pattern chart, that’s exactly what you will see in the pool.  Homeowners who purchased liners from McEwen Industries several years back may have purchased a pattern that had a solid blue or white sidewall in between the floor and the tile border.

Today, all of those patterns that had the solid color sidewall have been discontinued in response to consumer preference.  As we started offering more and more patterns with the floor pattern coming up to the tile, the solid color sidewall patterns just dropped in popularity.

Another reason the solid color sidewall patterns were discontinued was that the solid sidewall would sometimes get stretched onto the floor during installation, resulting in a messy appearance.  With the floor pattern coming all the way up to the tile, that’s no longer a concern.

Visit our website and check out our liner patterns – what you see is what you get.

Which pool liner thickness should you choose?

Oftentimes people ask us which liner material is “better:” the 20 mil or the 27 mil?

In reality, there is no “better” liner.  The most important choice is not the thickness of the material, but the liner pattern that you choose.

Choose the vinyl liner pattern that you like the best.  If it comes in 27 mil at no extra charge, take it, but don’t pay extra for it.  You shouldn’t pass on your first pattern choice just to get the thicker material.  In our opinion, there is no meaningful advantage to thicker material.  There is no difference in wear, durability, longevity or warranty.

Liners fail for two reasons.  The ink fades or the material dry rots above the waterline.  Thicker material solves neither of these problems.

Most importantly, choose a vinyl liner pattern that speaks to you.  You are going to be looking at that pattern in your backyard for at least the next seven years.  Ultimately, the pattern you choose should outweigh the thickness of your liner material.  It is what you think looks the best that matters.

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