The direct route to a sustainable solution for schools

Carole Armstrong of Delabie UK considers the compelling advantages of direct flush over cistern flush WCs for projects in the education sector

In the education sector, WCs account for over two thirds of total water consumption. Traditional cistern flush mechanisms installed in school toilets were designed for domestic use and are not suited to public facilities. They are often specified in schools and colleges through habit and because the initial investment is lower, but this can prove costly over time.

Concerns about cisterns

Cistern flush mechanisms are not ideal for public use. Comprising plastic components, they are subject to intensive use and rough handling. Scale build-up in the cistern may damage the seal, resulting in leaks. A leaking WC mechanism can often go undetected as the water seeps past the mechanism seal silently, streaming down the pan into the bowl, and is often concealed by the overflow. Thames Water estimates that a leaking toilet can waste up to 400 litres per day. Even if the leak is detected rapidly, maintaining a large number of toilets is time consuming. Mechanisms can be difficult to access and parts wear out quickly with intensive use, requiring frequent servicing.

Intensive use

Direct flush vales are specifically designed for highly used toilets. The solid brass mechanisms and shock-resistant control buttons will withstand intensive use and even deliberate misuse. Relying on water pressure from the system, direct flush valves have no cistern and reduce the risk of leaks. The mechanism can be isolated via an integrated stopcock, allowing direct access to the cartridge, which can be replaced without having to remove the flush valve. Although more expensive than systems comprising plastic components, over time they are more cost effective thanks to lower maintenance costs and their longer lifespan.

Changing user habits

Toilet usage in educational facilities is characterised by short periods of intensive activity. One limiting factor for cisterns is the lack of dynamic pressure to ensure a hygienic rinse and full flush. This is most evident during busy periods as the cistern takes time to refill for subsequent flushes. Changing to a direct flush system can be more hygienic and save water. The flush uses the dynamic pressure of the system and there is no refill time, so successive flushes are possible during busier periods. This also avoids the problem of users trying to flush with a half-full cistern.

Flushed with efficiency

Since 1999, Water Regulations require new WCs to have a maximum flush volume of six litres, with no minimum volume specified. BREEAM’s environmental accreditation scheme sets its baseline flush at six litres, with maximum credits for a three litre flush. Dual flush systems delivering three or six litres are increasingly popular, however, the flush must be sufficiently powerful to guarantee a proper discharge of the waste water to avoid blockages. Direct flush harnesses the system pressure to guarantee an effective flush with a single flush. The direct flush with dual flush is pre-set at three or six litres and can be adjusted to two or four litres for ecological or smaller children’s WC pans. This prevents unhygienic splashing and avoids the risk of slipping on wet floors.

Improved hygiene

School holidays also pose a problem. WC cisterns left unused over time pose a hygiene risk. Stagnant water, scale deposits and ambient temperatures lead to the development of bacteria which then spread in aerosol format when the toilet is flushed. Direct flush eliminates any standing water from the system and there is no scale or impurity build-up. For optimum hygiene, an electronic direct flush valve will remove any physical contact with the option of a ‘hygienic duty’ flush every 12 or 24 hours.


Schools and colleges can experience high levels of misuse and even vandalism. Heavy handed users can easily break fragile mechanisms or cause deliberate flooding with conventional cistern WCs. By contrast, Direct flush valves have vandal-resistant features that prevent wilful abuse. Aside from the hard-wearing mechanisms (designed to withstand over 500,000 operations) they also feature anti-blocking mechanisms, which only flush once the push-button is released. Similarly, electronic systems can be programmed to shut-off automatically if the sensor is permanently activated or the WC is flushed too frequently within a given time period. The controls are designed to be flush to the wall and cross wall models are also available which can be installed in a service duct, so that the user has no access to the mechanisms. Direct Flush systems can provide a sustainable solution for toilet facilities in education establishments. Designed for intensive use in public environments, they provide a hygienic solution that manages water consumption, adapts to the usage demands of schools and colleges, and are easy to maintain. Breaking the habit of specifying domestic style cisterns will deliver long term dividends in terms of sustainability, improved hygiene and low maintenance.

Carole Armstrong is the marketing manager at Delabie UK