Expert Guide to Choosing Tap Washers

What is the Definition of a Tap Washer?

Tap washers, also referred to as sealing washers or packing washers (in some tap varieties), are straightforward disc-shaped components with a central aperture. They act as a form of gasket, aiding in sealing off the mains water flow behind a tap when the tap handle is turned to the ‘off’ position.

What Can Tap Washers Be Used for?

Tap washers are typically included in plumbing kits and toolboxes. Most often, tap washers are used for quick replacement tasks. Generally, they serve as the preferred fix whenever a tap drips, leaks, or becomes hard to operate. Some instances where tap washers are utilized include:

• Basin mixer tap washers
• Bath tap washer replacements
• Hot water tap washers
• Kitchen tap washers
• Lever tap washer replacements
• Mixer tap washers
• Outside tap washers
• Pillar tap washers
• Swan neck tap washers

What is the Purpose of a Tap Washer?

Tap washers are essential components used in almost all types of taps, primarily to regulate water flow. They also help to prevent leaks and contamination when the tap is closed. No matter the type or material of the washer, their fundamental function is to press against the seat or flow valve inside the tap assembly. This creates a sealed barrier that stops water from reaching the spout when the tap handle is turned to the 'off' position.

How Do Tap Washers Function?

They serve their purpose by forming a watertight barrier between the tap seat and the spout. The construction material of most tap washers allows them to fill and smooth out any uneven gaps between different parts of a tap fitting (typically the valve and the tap seat), effectively sealing off the tap spout from the valve.

When a tap head is turned on or off, a rotating screw causes the tap washer to move up or down (respectively) within the tap assembly. This lifts it away from the seat and opens the flow valve, allowing pressurized mains water in the plumbing system to flow through the tap spout at varying volumes and speeds. Tap washers are usually made from materials that can be compressed to form a watertight seal (although there are exceptions for certain tap types). This allows them to seal the valve opening more effectively, even when general wear and tear have caused small surface irregularities over time.

However, there is a limit to the amount of wear a washer, seat, or valve opening can endure before the sealing properties are no longer effective. Eventually, the washer or other moving parts of a tap will need to be replaced. This is most often due to damage from water erosion or physical stress and degradation caused by repeated mechanical or compression forces during normal use.

Ceramic Tap Washers

Ceramic tap washers, sometimes referred to as ceramic disc washers, are commonly found in newer tap assemblies. Typically installed in 'quarter-turn' taps and monoblocks (mixer taps), these washers eliminate the need for multiple rotations of the tap head to control water flow.

Unlike traditional sealing washer types, ceramic tap washers operate differently. Instead of using nylon, rubber, or fiber washers, they employ a pair of closely fitting slotted ceramic discs. One of these discs remains stationary, while the other can rotate up to 90 degrees, equivalent to a quarter-turn.

In the 'on' position, the slots in both discs align, facilitating water flow through the spout. When the tap is turned off, one ceramic disc rotates to misalign the slots, effectively blocking water passage.

There are various advantages to this type of mechanism:

• Ceramic tap washers are hard-wearing and highly resistant to water erosion, meaning that they tend to last a long time
• They’re very low friction in operation, further contributing to both longevity and a smoother, easier tap action - hence being used more often on lever-style taps
• While they will eventually need replacing just like any other washer, ceramic discs are widely available, and there are relatively few different size options to choose between when it comes to ceramic tap washer spares

When it comes to selecting tap washers, the most important choice usually comes down to picking out the right size for your tap assembly. While many taps can cope with a range of washer types (with the exception of ceramic disc taps), one particular tap washer material will probably be best for your specific install location, tap type, and general style of use.

Tap Washer Choices by Size

What type of tap washer should I buy? The one aspect that tends to cause more confusion and uncertainty than any other regarding this question is often getting the correct sizing.

Depending on the tap type and the specifics of its assembly, you may need large tap washers, mudguard washers, small tap washers, or even mini versions. Commonly used washer sizes for various indoor or outdoor taps include:

• 1-inch tap washer
• 15mm tap washer
• 16mm tap washer
• 9mm tap washer
• 17mm tap washer
• 20mm tap washer
• 32mm tap washer
• 40mm tap washer

Similarly, it’s worth noting that many tap washers are also listed and sold by metric or ‘M’ size ratings (M3, M4, M8, M10, etc).

By far the easiest way to ensure you’re picking out the right washer size for your tap is to physically remove the old one and measure it. That way, when you decide to buy tap washers online, you’ll be able to sort products by the exact size you need with a single click.

Alternatively, if you are a professional or are working with multiple different types of tap, it can be more economical to simply buy a tap washer replacement kit. These come with a range of common washer sizes, so you’ll be covered for almost any replacement you need.

If you’re trying to make a decision between different types and sizes of commonly-used tap washer products - for example, rubber tap washers vs nylon or fibre - it can be helpful to compare tap washers directly. The table below should help with this, giving a general illustration of some typical uses for various different washer kinds and sizes.

Can I change a tap washer myself?

In most cases, the answer is yes. However, you will need access to a few common tools, plus to have a basic understanding of the role and function of a tap washer. You will also need to have familiarised yourself with the main parts of a tap assembly.

Fitting a new tap washer is not a particularly lengthy or complex fix. It will generally be a fairly hassle-free experience, provided you prepare the area properly, and learn the key steps to the job before you start. Important steps to take before tackling a tap washer replacement include:

• Blocking off the drain or plug hole (to prevent loss of any small components or fasteners)
• Shutting off the water supply to the tap you’re working on prior to any disassembly