Many pool repairs are carried out from inside, without the need to open pipes or dig. Resin repair, polymer injection and sealing allow circuits, fittings and lights to be repaired directly. Not every leak, however, can be solved this way; here we explain what can be fixed without works and what requires a major intervention.
What resin repair is and how it works
Resin repair is a technique that injects resin or polymer inside a pipe to seal cracks and micro-fractures without removing it or breaking the floor. The resin flows through the pipe until it reaches the crack, where it adheres and hardens, creating a watertight seal from inside. It is mainly used on pool circuit pipes (skimmer, return, pool cleaner line).
Repair resins are chosen according to their compatibility with chlorine and pressure; durability depends on the product and the application.
Three operations are often confused and should be distinguished:
- Draining the basin: removing the water from the pool. It is usually not needed to resin a circuit pipe.
- Isolating and draining the circuit: separating the affected pipe section from the rest of the installation and removing water from that section only; the basin can remain full.
- Drying the pipe: a requirement for resin repair; the inside of the section must be dry before the resin is applied. How it is dried and how long it takes depends on the product and the installation.
Sealing fittings, lights or wall penetrations from the basin is a different operation: it does not consist of resin-repairing a pipe and, depending on the case and product, can be done without draining the pool.
What can be repaired with resin repair and injection
- Skimmer pipes: If the leak is a crack or micro-fracture in a straight section, it can be resin-repaired directly.
- Return pipes (pressure line): Same procedure. The resin fills the pipe from inside and seals it.
- Pool cleaner circuit: It can also be resin-repaired if the leak is in a rigid or flexible pipe that is not bent.
- Fittings and connections: Sealed with special elastomers without dismantling.
- Lights: Many light leaks are closed with polymers without replacing the unit.
- Wall penetrations: Aged seals can be reinforced by polymer injection.
The advantage is that no floor needs to be opened and the original pipe is kept; durability depends on the product and the application.
Repairing each circuit: specific options
Skimmer circuit
The skimmer (surface collector) receives water through a flexible or rigid pipe. If the leak is at the skimmer-pipe connection, it is sealed by polymer injection without dismantling anything. If the pipe has cracks along its length, resin repair works well. If the pipe is crushed or has several breaks, the pipe is replaced.
Return (pressure) circuit
Return pipes carry filtered water back to the pool. If they leak on straight sections, resin repair is very effective. Return fittings often leak; they are sealed with elastomers. If the damage is large (a broken pipe), that segment must be replaced.
Pool cleaner circuit
This circuit is subject to a lot of movement (the hose moves). If it leaks at the hose connection, the clamp is tightened or replaced. If it leaks in the buried pipe, resin repair is proposed for a crack, or pipe replacement for a break.
Main drain
The main drain (bottom outlet) has a ball valve that sometimes leaks. If only the valve is at fault, it is replaced (it is a single part). If the drain pipe leaks, pressure testing is used to locate the leak, and then resin repair or pipe replacement is decided.
When an opening is needed
Not every leak can be solved with resin repair. A deeper inspection (exploratory opening) is needed in these cases:
- Crushed flexible pipe: If the pipe is bent or compressed, resin repair does not work. The pipe must be removed and replaced.
- Several consecutive bends: If there are many changes of direction in a short section, the resin does not fill all the cavities properly. Pipe replacement is recommended.
- Visible break: If the pipe is split or open, it cannot be sealed from inside. It requires replacement.
- Damaged sump or valve: If the component is broken, it is not repaired; it is replaced.
An inspection with a camera (endoscopy) inside the pipe shows its internal condition and helps decide whether it is resin repair or pipe replacement.
Decision procedure: how it is determined
After locating the leak, an assessment is carried out:
- Pressure test: Identifies the circuit where the leak is.
- External visual inspection: Checks where the water comes out (if visible).
- Camera or access: Where possible, a flexible camera is introduced into the pipe to see the damage from inside.
- Decision: If it is a crack or micro-fracture in a straight pipe, resin repair is proposed. If the damage is greater, a pipe replacement is quoted.
- Repair: The chosen solution is applied. For resin repair, the affected section is first isolated, drained and dried.
Resin repair versus pipe replacement
Resin repair can be less invasive than replacing the pipe, but it requires a precise diagnosis. Pipe replacement can be more expensive and may require excavation, but it is the solution if the damage is significant. To understand pool repair costs better, see our complete guide on the factors that influence the price.
After the inspection, your technician will explain which technical option is best for your case. There is no "universal repair"; it depends on where the leak is and the condition of the pipe. You can also consult general costs of repairing water leaks for a general reference.
Skimmer repair: a common case
Skimmers are a frequent source of leaks in pools. The problem is common because the skimmer is subjected to pressure fluctuations (pump suction and water level variations) and to plastic ageing. There are several repair options depending on where the leak is:
Leak at the skimmer-pipe connection
This is the most frequent leak point. If the seal between the skimmer and the flexible pipe is damaged, polymer is injected to reinforce the seal without dismantling. It works well in many cases.
Leak through the skimmer wall
If the skimmer body is cracked, resin repair does not fix it and the skimmer is replaced. The technician recommends this option after seeing a structural crack.
Leak in the flexible inlet pipes
The flexible pipes that connect the skimmer age and crack. If the crack is small (a micro-fracture), resin repair works well. If there is a visible puncture or the pipe is badly damaged, the pipe is replaced.
Leaks in elbows and connections inside the skimmer
Some skimmers have internal connections (elbows) that leak. Depending on the model, resin is sometimes injected through the water inlet; at other times the internal connection must be replaced.
A professional diagnosis with visual inspection and a camera helps determine the best technical solution for your skimmer.
Post-repair maintenance
The curing time depends on the product and must be stated by the technician. A subsequent pressure test allows the result to be checked.
When to call a professional
If you have detected a leak in your pool and want to know whether it can be repaired without works, request an assessment. A professional inspection with pressure testing and camera will determine what can be repaired from inside and what requires major work. With that diagnosis, you will make the best technical and economic decision.
