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The variety of taps and washbasins on the market gives Architects ample choice in selecting the perfect blend between the two for their commercial washroom. However, as exciting as the search may be to sieve through each washroom supplier’s range, choosing any tap with any wash trough comes with more to consider before making that final purchase.

Blindly selecting these fittings without proper assessment of how they may function together can result in tap lengths being too short or too long for the washbasin. It can cause a ripple effect of issues leading to design flaws, unpleasant user experience and missing the WELL standard recommendations.

Dolphin Solutions specialises in manufacturing and supplying a wide range of taps and wash troughs in various designs and dimensions to suit our client’s requirements. Find out why choosing the perfect blend between tap lengths and washbasins is essential.

Click here to to read about how to comply with the WELL standard in your tap and basin specification.


Tap lengths, styles, and proximity

Tap lengths and styles should cater to the size and design of the washbasin. Factors to consider when choosing the right tap length are:

  • Proximity of tap fitting to the wash trough
  • Type of tap spout
  • Type of washbasin
  • User experience
  • Supporting effective handwashing
  • Aesthetically pleasing
  • Minimise water splashing to an absolute minimum

Types of taps and tap lengths

Angled tap lengths for your washbasin


A 55⁰ tap spout is a popular choice amongst designers as it is a classic elegant style with laminar flow to reduce water splashing. However, reducing the splash only works when the column of flow is in a position that does not interfere with the edge of the washbasin.

This cross-section illustrates a tap above the step of a washbasin. It shows the difference between a 180mm tap length and a 150mm tap length in a 350mm washbasin.

The column of flow in the 180mm tap length depicts the angle hitting the inside edge at a height that reaches the top of the basin, which can result in water ricocheting up and out onto the vanity or the user. The water splash is due to the proximity a user cups their hands between the water flow and basin edge combined with the water pressure gushing out.

However, the column of flow in the 150mm tap length depicts a far lower angle directed at reaching the washbasin base, which significantly reduces or eliminates the possibility of water splashing out.

Tap length is too short for your washbasin

Too short

If the mounted tap is set too inwardly or is too short, the water can splash behind the basin creating a messy puddle just after one use. Another example, if there are ten users for one washbasin, a significant amount of water can be splashed on the back and accumulate to an extent where the water starts running along the vanity, down the beautiful cabinetry, and onto the floor.

Tap length is too long for your washbasin

Too long

Whether the tap spout has a 55⁰ or 90⁰ angle or has a straight projection to the outlet, the tap length still needs to be carefully compared to the washbasin dimensions. Too long creates the same problem where water splashes out and runs down the front of the vanity unit or onto the user.

This picture shows a 300mm basin with a 175mm wall-mounted tap, and as you can see, the projection of the tap is far too close to the front edge of the washbasin.

In this instance, choosing a tap that is a mere 25mm – 35mm less makes a significant difference for a small basin. If installation happens before understanding these factors, it could cost the project thousands of pounds to pull these out and install the appropriate size. This cost blows up even more if the taps were touch-free and not manual.

Something else to bear in mind, even if a 150mm tap is selected in this instance, the mounted fixing at the back must be accounted for as it adds extra length to the tap. This ultimately defeats the objective of reducing the tap size and takes you back to square one.

Tap length is too tall for your washbasin

Too tall

If a surface mounted tap is too high and the washbasin has a short depth, there is a risk of water dripping down the back of the basin when users wash their hands. This is a common issue when the tap is too high, the spout is too short, and the washbasin is too shallow therefore, avoiding this issue will depend on the type of basin installed. For example, having a larger and deeper bowl would be ideal for a tall tap.

Sensor taps

Sensor taps with a long or short tap length also have various factors to consider. Too short runs the risk of water splashing on the back of the vanity during handwashing but too long means a user needs to stretch their hands out far enough to activate the sensor. The longer the spout, the further away a user is from reaching the sensor. Essentially, this results in a user watering their wrists or arms whilst trying to keep the water flowing in front of the sensor.

Mounting the tap in a position that is not too close or too far from the basin combined with choosing a washbasin suitable for the sensor tap design can avoid this risk.

Tap lengths for your washbasin positioned right

Just right

It is recommended to have the tap length positioned just short of the trap rather than a longer tap length going over the trap to avoid the possibility of water splashing onto the user or the floor.

Wash basin click clack

Sometimes, a washbasin is purchased from one washroom supplier and the tap from another without consideration of the dimensions. It may happen that the column of flow from the chosen tap length is positioned directly over the trap in the middle of the basin. To address this, installing a click-clack can prevent direct water flow into the drain and wastewater in the drainage pipe from splashing up.

Tap lengths for your washbasin

Keeping within WELL standards

If the goal is to achieve WELL Certification, then supporting effective handwashing is a requirement that refers to all spaces for all washbasins where handwashing is expected.

WELL requirements:

  1. Tap design must prevent water from flowing directly into the drain or a domed waste trap must be installed.
  2. Water must not splash outside the washbasin when the tap is opened in full.
  3. Newly installed washbasin to meet these design parameters:
    1. Washbasin is at least 230mm across, measured at the point where a user places their hands to wash.
    2. Length of the water column from the tap spout to the washbasin is at least 200mm.
    3. Water column is at least 75mm away from any edge of the washbasin.

The Dolphin range of solutions

As a trusted advisor, we assist you with choosing the correct tap lengths for your washbasin by investigating deeper into your commercial washroom project plan. We determine if the tap length is suitable for the type of wash trough chosen and go further to assess whether the project as a whole meets standards and commercial washroom regulations.

“Add to cart” is not where our service ends. We dedicate our business to creating the finest commercial washroom experience which means you receive full attention on a larger scale than merely adding our range of products to your design.

Collaborate with us, ask questions, and partner with a commercial washroom supplier you can trust.

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