We’re partnering with the NBS Source To provide easy access to detailed product information for you and your construction partners, streamlining the specification process, our online library covers technical specifications such as load-bearing capacity, dimensions, drainage and resistance to damage.
In this piece, we explore what can happen when specification goes wrong in regard to load class, and explain what a product that can perform looks like in comparison.
Poor drainage specification can lead to financial losses
Let’s look at covers and how much weight they can tolerate. If this is wrong, it can lead to serious issues, extra costs, and perhaps legal issues if an injury arises from the wrong load rating.
Incorrect load specification means the cover and frame can often end up being damaged by the weight of vehicles (see images below).
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Image 1 – damaged cover and frame
In more serious cases, the cover may even fail completely, leaving to a deep cavity that can damage vehicles and present a health and safety hazard (see image 2 below).
Image 2 – failed cover
This leads to dangers, liabilities, and costs. Had the specification incorporated the correct loading class in the photos above, these issues would not have occurred.
But what constitutes the correct loading class?
Taking the strain – how do drainage load classes work?
Load classes for covers range from A15 (for pedestrian and cyclist use only) to F900 (for heavy loads such as airports), with different levels in between, each suited for different environments.
So, for heavy traffic areas (bus depots, car parks, petrol stations, municipal maintenance facilities, fleet fuelling sites), the correct class for the wheel loads is D400 – which means the cover can withstand weights of up to 40 tonnes.
Even in lighter-traffic areas, where traffic weight and volume increase over time, or where there is doubt about the accuracy of these designations, its safer to choose a load class higher than originally planned to be cautious.
Load rating isn’t the only measure of a cover’s performance, resilience, or suitability for the job, so it’s important to consider all factors.
D400 done the Clark-Drain way
Our D400 recessed ductile iron cover offers benefits that no other supplier’s products can match.
Built for busy, paved areas, this product handles heavy, slow-moving vehicles better than a traditional steel cover would. It demonstrates higher levels of flexibility, durability, and surpasses the 40-tonne load requirement.
The design concentrates the weight on the strongest parts of the frame flanges, strengthening it whilst removing strain on the base.
The corners are bigger, meaning it is easier to install securely. In addition to this, the tray can hold various materials like tarmac, paving, or concrete.
As ever, we go further to deliver better. The use of ductile iron, for example, means the cover can be installed into a roadway, whereas the use of steel covers is not permitted.
Ductile iron doesn’t rust or corrode under traffic, making its frame and covers more durable, longer-lasting, and provide better returns on investment. They won’t seize or fuse, and so will continue to open with ease, inspectable, and maintainable throughout their lifespan.
And in line with our commitment to sustainability and environmental responsibility, the D400 cover is fully recyclable at end of life.
Specification that goes a step further
In short, whilst the wrong specification can fail the job in hand, the right choice of product for the specification required can deliver benefits above and beyond – something we at Clark-Drain have been doing consistently for our customers since 1963.
For more information on our D400 recessed ductile iron cover, give us a call on 01733 765317, send us an email to [email protected], or fill out our contact form, and a member of our friendly team will be in touch with you shortly to discuss your requirements.