What to Do About That Spooky Banging Sound Behind the Walls

Every house has its unique soundtrack of little noises it makes, from creaks and groans to thuds and pops. Most of these are just products of the house settling and wood contracting or expanding as temperatures change. But if loud banging or knocking sounds are coming from inside the walls or under the floors, there’s cause for concern. 

These frightful sounds aren’t caused by ghouls, ghosts, or goblins but by a slightly less terrifying phenomenon called water hammer. Apart from being annoying and downright spooky, water hammers can damage pipes and fixtures and may even indicate larger issues with the plumbing system – so this article will explain what a water hammer is, its risks, and how to get rid of it!

What Exactly Is Water Hammer?

A water hammer, also known as hydraulic shock, is a pressure surge or shockwave inside a water pipe that occurs when the water flow suddenly stops or changes direction (the technical term for this is transient flow). This usually results in a banging or knocking sound caused by the shockwave traveling through the pipe. The pipe may also rattle against any surrounding wood if it’s not tightly fastened, contributing to the noise. A water hammer is generally the culprit when anyone refers to banging or noisy pipes.

Water hammers are usually caused by a valve closing suddenly, such as the automatic valves in a washing machine or dishwasher. However, even a faucet being turned off quickly can cause a hydraulic shock. But in many cases, excessively high water pressure is at the root of the problem – if the water is moving faster and under higher pressure, more force will be behind it when it suddenly slams into a closed valve.

What Are the Dangers of Water Hammer?

Apart from the irritation of noisy pipes, water hammers can cause serious issues with the plumbing system. Over time, the constant pressure surges and shockwaves can loosen pipe fittings and joints, potentially causing small leaks or even a ruptured pipe. The sudden pressure surge can even cause old or corroded pipes to burst. 

If this weren’t bad enough on its own, the resulting water damage can be extensive – not to mention expensive to clean and repair. A water hammer can also damage any valves that bear the brunt of the shockwave. This will mainly affect automatic valves that close very rapidly, such as those in washing machines, dishwashers, and toilets.

How Do the Pros Fix Water Hammer?

When it comes to fixing water hammers, professional plumbers have a few options at their disposal. One of the first things they will do is check the home’s main water pressure regulator to see if the water pressure is at a normal level - typically somewhere between 50-70 PSI - and adjust it if necessary.

The next step is typically to see if the home’s air chambers are full of water (if the house has any). Air chambers are vertical sections of pipe in the water supply system that act as a sort of buffer, giving water somewhere to go if there’s a pressure surge. If the air chambers are full of water, they must be drained. Another water hammer fix professionals may employ is to install water hammer arrestors near potentially problematic valves. These small devices serve a similar function as air chambers, acting as cushions where sudden changes in pressure and flow occur. 

These fixes - not to mention diagnosing the cause of the water hammer - are outside the realm of DIY plumbing repair, so to make sure the issue is fully resolved and avoid damaging the plumbing system, it’s always best to leave water hammer repair to the professionals!

About Falcon Plumbing

Falcon Plumbing has over 35 years of expertise serving Miami Lakes and the surrounding areas. They provide upfront pricing with no extra charges for overtime work and personal attention. Call them today for plumbing services in Miami Lakes, FL.

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