Why is the drain leaking: the main reasons, what to do and how to fix the leak

In most cases, a drain is leaking not because of one critical defect, but because of a combination of minor errors. Most often, these are installation errors, worn seals, incorrect slope or overloading of the system.

Sometimes the problem occurs due to clogging or weak fixation of the elements. As a result, water starts to come out where it shouldn't be.

The Ukrainian-Finnish company "Akveduk" designs drainage systems so that they operate stably even under high loads. However, drainage, like any system, requires proper installation and maintenance.

The main signs that the drain is not working properly

The problem can be noticed before serious consequences occur. It is important to pay attention to typical symptoms.

The most common signs:

• water flows down the facade of the building;
• drops appear at the joints of the gutters;
• water overflows the edge;
• wet areas appear near the foundation;
• The watering can is operating with overload.

Such manifestations often mean that the stormwater system is leaking and diagnostics are required.

Why is the drain leaking: the main reasons

When a stormwater system leaks, the cause is almost always technical. It is related to installation, wear, or improper selection of elements. It is important to understand: even a small error in one node can cause a leak throughout the entire line.

In most cases, a drain does not leak immediately. At first, minor leaks appear, which over time develop into a permanent problem.

The earlier the cause is identified, the easier and cheaper it is to eliminate it. 

Installation errors

The most common reason is incorrect installation. It is at the installation stage that the reliability of the entire system is laid.

Typical errors:

• incorrect gutter slope;
• weak fixation of the brackets;
• too rare a step of holders;
• skewed joints;
• lack of thermal gap;
• violation of the tightness of the joints.

If the brackets are installed with a large step, the gutter begins to sag under the weight of water and snow. Gaps quickly appear in places of deformation.

This creates a situation where the gutter joints leak and water starts to leak out even with a little rain.

A separate problem is the incorrect position of the gutter relative to the edge of the roof. If it is offset, some of the water simply flies past the system.

Wear of materials and seals

Over time, elements age. This is a natural process, even for high-quality systems.

Problems arise due to:

• loss of elasticity of EPDM seals;
• deformation of PVC during temperature changes;
• corrosion of metal parts;
• microcracks in load areas;
• expansion and contraction of the material.

This is especially noticeable at the joints. The sealant no longer presses tightly, and the tightness is broken.

As a result, the drain leaks even when initially installed correctly. This is a typical scenario for systems that have not been serviced for several years.

Incorrect system calculation

Another critical reason is mistakes at the selection stage.

If the system does not meet the load:

• water does not have time to enter the pipe;
• there is an overflow over the edge of the gutter;
• funnels and risers are overloaded;
• the pressure in the connection points increases.

This often happens when the roof area is large and the diameter of the gutter and pipes is left standard.

In this case, the drain leaks systemically, not locally. The problem manifests itself during heavy rain and repeats itself again.

It is also worth considering the number of drain points. If there are not enough of them, even a properly installed system will not cope with the volume of water.

Why do gutter joints leak?

A separate weak node is a connection of elements.

Causes of problems:

• dirt or leaves in the joint area;
• worn seals;
• incorrect fit of elements;
• skew during installation;
• thermal expansion of the material.

This is where problems most often arise, resulting in leaking gutter joints, even if the entire system appears to be in good working order.

How to find the cause of the leak yourself

Before repairing, it is important to accurately determine the source of the problem. Without this, even high-quality repair can only give a temporary effect. If the drain is leaking, it is worth acting sequentially: from a simple inspection to a local inspection of the nodes.

The main rule is to look for the cause, not the effect. Water may leak in one place, but the problem may be in a completely different place.

Quick diagnostics after rain

The best time to check is right after a rainfall. This is when the system is under load and weak spots become noticeable.

After rain, check:

• gutter joints;
• the area of ​​the funnel and the pipe entrance;
• vertical pipes along the entire height;
• brackets and mounting points;
• areas where water overflows the edge.

Pay attention to the nature of the leak:

• if water drips in spots, the problem is in the joint or seal;
• If it overflows along the entire length, it is probably due to incorrect slope or insufficient capacity.

This way you can quickly determine where exactly the stormwater system is leaking and which node needs attention.

Additionally, it is worth looking at the facade after rain. Traces of water or dirty streams often directly indicate a problem area.

What can be checked without disassembling the system

Most basic problems can be found without dismantling. This saves time and allows you to quickly assess the condition of the system.

Without disassembly it is worth:

• inspect the seals for cracks and gaps;
• check whether the fasteners and clamps have loosened;
• assess the slope of the gutter visually or by level;
• clean gutters from leaves, sand and dirt;
• check the funnel for clogging;
• conduct a test with water from a bucket or hose.

The water test is one of the most effective methods. Simply pour water into the upper part of the gutter and follow its movement. If a leak appears somewhere, the problem is localized.

If during the inspection it is visible that the drain is leaking in several places, this is a signal of a system error. In this case, it is worth checking the slope, calculation and condition of all connections.

Regular diagnostics allow you to detect problems at an early stage. This is much cheaper than eliminating the consequences of constant leaks.

How to fix the problem depending on the type of drain

When a drain is leaking, it is important to consider the material of the system. PVC and metal behave differently, so the approach to repair is different.

There is no one-size-fits-all solution. What works for plastic may not work for metal.

If the problem is in the plastic gutter

In PVC systems, most often:

• seals are shifting;
• cracks appear at the joints;
• deformation occurs due to temperature.

Decision:

• replacement of seals;
• joint correction;
• replacement of damaged elements.

If the problem is in the metal gutter

In metal systems, the problems are different:

• corrosion in places where the coating is damaged;
• weakening of joints;
• violation of sealing of plugs.

Decision:

• sealing of joints;
• anti-corrosion treatment;
• replacement of individual elements.

When is repair enough and when is replacement necessary?

It is not always necessary to change the entire system.

Repair is sufficient if:

• local leak at one joint;
• one seal is worn out;
• there is a blockage or skew.

Replacement is required if:

• a drain flows along the entire length;
• the system is deformed;
• the installation was made with gross errors;
• The elements are incompatible with each other.

How to prevent recurring leaks

Prevention is always cheaper than repair.

Recommendations:

• gutter cleaning twice a year;
• inspection after heavy rains;
• control of fasteners and brackets;
• inspection of joints before winter;
• bandwidth check.

Regular maintenance reduces the risk of a leaking stormwater system.

A properly installed and maintained drain works for years without problems. The main thing is not to ignore small signs and to respond to changes in the system's operation in a timely manner.