Is there a special type of liner for an indoor pool?

 If you are renovating or installing a new PVC lined indoor pool, consider the type of PVC liner you are using.

Some people say all liners are the same, with the only difference being thickness, but that’s just not true. Most liners are made from a PVC film. This flexible, stretch fabric relies on the structure of the pool, and the weight of the water to maintain its shape. This works well in most situations, and with high quality options available, it’s an excellent surface finish for both above ground and inground swimming pools that are outdoor.

However, under certain environmental conditions (likely to be found in an indoor pool) the fabric of a standard PVC liner can sometimes start to ‘absorb’ water.

PH, total chlorine levels, ventilation and bathing load are all thought to be contributing factors. If the liner fabric begins to absorb water, it eventually expands the PVC, which then causes wrinkles to form in the pool. The wrinkles usually start on the floor of the pool, but can be all over the whole liner. If you look closely at a section of affected PVC, you can see the surface is weakened, and prone to forming tiny cracks that can develop into larger tears.

If this happens, there is no reversing of the process, and the life span of the liner is greatly reduced.

While many indoor pools are surfaced with standard PVC liners without any problems, there is always a risk of it occurring in the right (or wrong) conditions, and it is best to avoid the risk completely in indoor pools, by using a reinforced liner.

AquaForce is a specialist reinforced PVC fabric which is suitable for use in indoor pools. AquaForce features an internal reinforcing layer that keeps the fabric stable in indoor pools, and virtually eliminates the risk of wrinkling.

With a three layer design, AquaForce has a PVC base ply, a layer of reinforced polyester mesh, then topped with another ply of PVC. All three layers are homogeneously bonded together during the manufacturing process to be permanently fused. The mesh reinforcing layer stabilises the fabric and stops it from shrinking or expanding. 

Traditional PVC liners can be delivered to site fully welded in one piece, but AquaForce reinforced PVC liners are always fabricated on site, as they do not stretch or form to the pool shape.

The rolls of the AquaForce fabric are laid in the pool and overlapped to form seams that are welded on site. Edges are then sealed, to stop water absorption through the fabric itself. AquaForce liners can be fitted to any pool shape, as the liner is cut and shaped in the pool on site, allowing it to be fitted over steps and benches and down into deep ends of all style of pools.

 So if you are looking to install a PVC liner in an indoor pool, we recommend the use of a reinforced PVC such as AquaForce, to reduce the risk of wrinkling. AquaForce is also recommended for use on Commercial PoolsIndoor commercial pool, bunbury WA AquaForce liner.

Fact #3: Wrinkling of Liners in Indoor Heated Pools

The strangest phenomenon I’ve seen in my thirty-something years in the liner business is “wrinkling liner material caused by indoor heated pools”. If you read my recent blog about chemical levels you would conclude that this problem relates specifically to imbalanced pool chemicals, but this is not the case from my experience.

It first started in the 80’s when a customer contact us to say the pool liner in their 50 metre long pool, had grown about one whole metre in length. I almost didn’t believe them, so I went to see it for myself.

When I inspected the liner, sure enough, there were wrinkles and folds of liner all over the floor of the pool. It looked like the reverse of a dry creek bed, instead of open cracks, these were folds of PVC in a random crazed pattern. After a lot of investigation by the fabric manufacturer, the conclusion was that this phenomenon was a reaction to a pool environment that was made up of the following factors:
· Indoor
· Heated
· Commercial use
 (like a training pool or public pool)

Another case which proved the validity of the study result to me, was a school pool in a cold climate. It was built as an outdoor pool and used for two years without any noticeable liner growth. Then, the school decided the pool would get more use if it was covered, so a new building was built over the top of it. It became an indoor heated pool and within one year, the liner had grown to have large wrinkles all over the floor.

How can this be? What happens is, under these conditions, the PVC absorbs water and therefore expands. The expansion becomes visible as wrinkles and there also appears to be deterioration in the strength and flexibility of the PVC; in severe cases I have seen cracking along the creases.

Different solutions were trialled like, maintaining a level of cyanuric acid (not normally needed for an indoor pool), using a lacquered fabric, using a printed fabric, yet nothing solved the problem and so it was concluded that unsupported PVC was not suitable for pools with these environmental conditions.

The fabric manufacturers’ no longer provide a warranty for their PVC when used for this application and so it used at the risk of the Purchaser.

There are plenty of domestic pools that are heated and located indoors which do not show any problems, but many of the commercial pools under these conditions will exhibit the considerable wrinkling caused by this phenomenon.