The Italian Association of Pool Builders was the first to draft a document, dedicated to industry professionals, that sheds light on a specific and controversial topic: the installation of PVC liners for swimming pools.
Anyone who builds pools knows that the most delicate moment of a project can be the final lining phase, often a source of dispute between clients and installers. This is partly due to the absence of a technical reference document to establish whether or not workmanship errors have occurred.
It is precisely this lack of shared reference points that leaves room for subjective interpretation, giving rise to expert assessments, lengthy delays, and costs borne by both parties.
Acquanet’s initiative
Faced with this gap, last September Acquanet – the Association of Pool Builders – decided to step in by pooling the hands-on experience of its members. It thus drew up, the first such document in Italy, a shared reference document: Guideline No. 02.
The aim is to draw clear boundaries between what the client can legitimately dispute and what instead falls within the normal characteristics of the product and its installation. The document applies to any pool lined with a reinforced PVC liner and is based, as its regulatory foundation, on UNI EN 16582-1:2015 on the general requirements for private swimming pools.
Here, in brief, is what it covers.
Reporting a defect
The document clarifies that any complaints must be addressed to the contractual point of contact, in compliance with the timeframes and procedures already set out under the Civil Code. For aesthetic defects, the pool must be filled with water before an assessment can be made, except in cases of obvious anomalies such as burns, stains, or significant discoloration.
Watertightness
Any leaks caused by the liner or its installation are never acceptable. However, if an inspection shows the cause lies elsewhere, the costs of the investigation are borne by whoever requested it.
Folds, wrinkles, and waviness
Here, the guideline sets a numerical threshold: up to 1 wrinkle per 50 m² (no larger than 15×3 cm) is considered within normal tolerance for rectangular pools, a threshold that rises to 3 per 50 m² for free-form pools or those with complex geometries.
Blisters or pockets
Since these issues can appear some time after filling, the guideline provides specific technical indications in its appendix.
Color variation
The gradual fading of the PVC’s color, due to sun exposure and/or suboptimal water treatment, is a natural characteristic of the material and is not grounds for complaint, unless it involves color differences that were never previously disclosed to the client.
Fill water quality also plays a key role (per UNI EN 16713-3 and UNI 10637): if it does not meet requirements, the warranty against discoloration damage is voided.
Color matching of PVC liquid touch-ups
As for the finishing of the more delicate weld points, a change in shade over time is likewise considered a normal characteristic and not grounds for complaint.
Welds and overlaps
Since the product is supplied in rolls (165 or 205 cm in width), joining multiple liner sections is unavoidable. The guideline sets precise aesthetic parameters: where an overlap is visible, its width must be kept consistent, preferably between 4 and 8 cm, with minimal variation from one point to another. Alternatively, where the flat-seam (butt-weld) technique is used, no overlap should be visible on horizontal surfaces.
Anti-slip surface
The document specifies that this property is guaranteed only at the time of initial certification. Any deterioration due to improper maintenance (such as aggressive detergents or abrasive tools) cannot be attributed to the product.
Issues related to the substrate/base
Should the installer find anomalies in the supporting base, they are obligated to report them in writing to the client or the site manager. If, despite this notification, work proceeds anyway, full responsibility falls on the client.
Warranty validity
The text notes that extraordinary maintenance must be entrusted exclusively to qualified technicians: improper work will void warranty coverage.
The significance of the document
The strength of Guideline No. 02 lies in offering, for the first time, a common language on a topic that until now has been left open to interpretation.
For pool building companies, it means being able to explain from the outset, in black and white, what to expect from a PVC liner — and what not to. For those commissioning the work, it means having an objective benchmark to refer to. For the industry as a whole, finally, the document can help reduce disputes and progressively raise the average quality of installation.
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