Banging Water Pipes: Causes And Simple Fixes

Banging Water Pipes: Causes And Simple Fixes

Anthony Barnes

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It can be quite worrying when you hear banging noises coming from your plumbing or water system.

It sounds like something has gone terribly wrong or is broken. It can also be very frustrating if the noise continues and repeats. 

There is often no need to panic. There are simple explanations as to why the water pipes are making those noises, and there are ways that you can fix them.

So what causes banging water pipes? And how can you fix it?

We have put together this useful guide to help you figure out what the problem is with your water pipes and how to resolve it. Keep reading to find out more. 

What Triggers The Banging Noise?

There are several times when you will notice the water pipes in your house making a banging noise.

It is usually when you turn on the hot water, turn on the cold water, or when you turn off the water.

You might also notice the noise at random points throughout the day or night, though this is less common. 

The noise will differ depending on whether you have plastic water pipes or copper water pipes.

The hot water pipes tend to make more noise as they expand with the heat, and then contract with the cold. 

What Are The Causes Of Banging Water Pipes?

There are several common reasons for your water pipes to be making a banging noise:

  • Loose Piping 
  • Water hammering
  • Worn out washers
  • Faulty shut off valve
  • Worn out ballcock assembly 
  • Bubbles in the pipes 
  • Blockages

Let’s take a look at each case in more detail, and how it can be fixed. 

Loose Piping

Loose piping is often the cause of banging water pipes.

If the pipe is loose then it will sway as the water moves through it, causing it to bang against the other pipes or against the walls.

Not only is this sound frustrating, it can also cause damage to the pipes or the walls if left unresolved. 

So how do you fix loose piping?

If the pipes are behind a section of drywall then you might need to get a professional to help you, as you will need to remove a section of the wall and fix it again afterwards. 

If the pipes are accessible, then securing a loose pipe is actually quite simple.

Check the diameter of the pipe and get hold of some plumbing clips or plumbing straps that are the right size.

The most common sizes are half an inch or three quarters of an inch.

If the pipes are plastic then you will need to use plastic clips, but if the pipes are copper then you can use plastic or metal clips. 

Identify the pipe that is loose by observing the pipes whilst the water is running. Once you have figured out which pipe or pipes are loose, then you can start securing.

Add a plumbing clip every foot or so, or more frequently if you think it is necessary. It is better to use too many clips than not enough. 

If you are adding the clips to a hot pipe then remember to be careful not to injure your hands as you do so. 

Water Hammering

Another cause of banging water pipes is water hammering, also known as hydraulic shock.

This is when the water is shut off suddenly, sending tremors through pipes and making them bang. It can also happen when an appliance like a washing machine shuts off. 

But why doesn’t this happen with faucets? Faucets have a gradual shut off, but appliances like dishwashers and washing machines have valves with an instant shut off. 

There is a simple way to fix water hammering. You need to absorb the building pressure with an area of gas just before the outlet.

In traditional homes, this can be done with a section of vertical pipe that has been capped which is placed by the outlet. 

A more modern solution is to use a pressurized chamber called a water hammer arrestor.

Inside the chamber is a lubricated piston with a rubber gasket. This will solve the problem. 

Worn Out Washers

A worn out washer can cause the pipes to whistle or squeak. This is a simple fix – all you need is to get a replacement washer.

The difficulty comes with trying to locate which washer is worn. It could be where the pipes connect to the faucets, or where they connect to an appliance.

The only way you will be able to tell is if you shut off the water and inspect each valve.

Faulty Shut Off Valve

Faulty Shut Off Valve

If the shut-off valve is faulty then this will cause an issue with the water pressure, and in turn will lead to the water pipes making strange noises.

These strange noises can be heard at any part of the house. The water will need to be shut off before the main valve can be replaced. 

Worn Out Ballcock Assembly

If the banging noise happens at the end of the flush cycle of the toilet, then the most likely cause of this is the ballcock assembly.

This is the part that is vital in the refilling of the toilet. It is fairly simple to replace. 

Bubbles In The Pipes

The system of water pipes in your home will not be made up entirely of vertical or horizontal pipes.

There will be some corner joints of the pipes, and this is where bubbles of air can become trapped.

These air bubbles can affect the pressure in the water pipes and cause them to bang. 

There is a simple solution. Make sure that the water is turned off at the mains, then turn on all the faucets around the house.

This allows the trapped air to be pushed through and escape. You might also need to flush the toilets to make sure that the tanks are drained. 

Once you have done this, wait half an hour before you turn the water back on.

Let the water flow for at least 5 minutes before turning the faucets off again. The toilets will then automatically refill. 

Cleaning Your Water System

It is important that you clean your water system regularly. If there is dirt or debris in the pipes it can restrict the flow of water. This will cause the pipes to vibrate and make noise. 

You should always ensure that the filters in your water system are working correctly.

If these filters are clogged then this will reduce the amount of water flowing through the pipes.

This will mean that the pipes will work harder, and therefore make more noise.

You should also check whether there is anything obstructing the pipes.

This includes tree roots, large rocks, or even small animals like squirrels. Small animals can cause damage to the pipes.

To prevent further issues with your pipes, you should try to keep your water supply as clear as possible.

This means keeping the garden tidy so that there are no leaves or other debris left lying around.

If you notice any unusual sounds coming from your pipes, then you should contact a plumber immediately.

They can help diagnose the problem and provide a cost-effective solution.

Blockages

Over time, sludge and dirt can build up in your water pipes, plumbing and central heating system.

This can cause blockages which leads to noisy pipes as the pressure in the pipes is altered. Chunks of sludge and dirt can also travel around the pipes, which also causes noise.

This is the kind of issue that you need professional help in order to fix. You won’t be able to remove the blockages and clean the pipes yourself.

You will need to call a plumber and get them to drain the pipes and service them. 

It’s important that you don’t try to do it yourself because there is a chance that you may damage the pipes further.

If you do manage to clear the blockage yourself, you may find that the pipes start to leak. This means that you will have to pay for a new pipe.

What Happens If You Get A Water Leak?

Leaks are one of the most common problems that people face with water pipes.

They can happen anywhere in the building, but often occur in areas that are difficult to access such as under floorboards or behind walls.

Leaks are caused by cracks in the structure of the building, or from damaged pipes.

Water can seep into these gaps and cause dampness, mold growth and rot.

Leaks can be easily identified by looking for signs of dampness, mold growth or rot.

However, if you notice a dripping tap or leaking sink, then you should contact a plumber immediately.

Leaking taps and sinks can be fixed by replacing the washer (the fitting that holds the rubber seal) or the supply pipe.

A leaking sink could require a complete replacement of the whole unit.

If you think that you have found a leak, then you should first isolate it by covering it with tape or masking paper.

Then you should call a plumber who can assess the situation and give you advice about how to fix it.

Summary 

If your water pipes are banging it can be very frustrating, and if left untreated these issues can cause long term damage to the pipes.

If you hear banging in the water pipes then you should try some quick fixes listed above.

This will help you to diagnose the issue and will hopefully help you to fix it quickly and without having to spend too much money.

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By Anthony Barnes

Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age