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Why Cover Specification Can Be a “Hole” Lot of Trouble (and How to Avoid It)

We’ve written many times in the past about specification, and its critical role in identifying suitable access and drainage solutions for construction project, as this is where errors are easily made but often only expensively corrected.

When it comes to access cover specification, incorrect weight loadings are often at the heart of these issues – as we highlighted in this recent article – but there can be costly confusion around other dimensional data too, with the most common, industry-wide culprit being clear-opening sizes.

Get these wrong, and you could see both budget and time disappearing down a hole – literally. 

Here’s what to look out for to ensure you get access cover specifications right first time.


What’s so unclear about clear-opening?

We said that this issue is industry-wide, and it certainly has been for as long as we’ve been in business – almost 60 years at the time of writing – but for something that can cause so much delay, annoyance, and cost, it’s surprisingly simple.

The clear-opening is the size of the hole that the manhole cover or access cover is covering – not the size of the cover itself (which will inevitably be larger). 

As an example, a specifier using the physical footprint of the cover is likely to specify an item that is too large for the hole available. That’s a big issue (and a lot of messy returns and reorders) when there are scores, hundreds, or even thousands of holes in a specific construction or groundworks project.

Of course, manufacturers and suppliers of access solutions do typically specify both the clear-opening and the external dimensions – take a look at the spec of our CD452 polypropylene cover, for example – but the confusion often occurs when customers aren’t speaking to merchants directly, but ordering without professional advice.

Always remember, to ensure you receive the right product, when it comes to cover specification, clear-opening is absolutely crucial.


Covering up a deeper issue?

That said, it’s also important to understand (as simple as this seems) when specifying access or manhole covers, that it is not acceptable to simply replace broken covers with new ones, no matter how accurate your specification.

If a cover is broken, the frame must be dug out and replaced along with the cover. Needless to say, it’s imperative at this point to ensure that the new frame and the cover are compatible with each other, both in terms of sizing, but also in terms of other ratings and certifications such as load, security, and so forth. 

A correctly specified cover combined with any other incorrectly specified item, such as the frame, compromises the specification integrity of the entire structure, so it’s important to work with a supplier that understands the specification process from start to finish.

For more information on access cover, manhole cover, and chamber specification, and how to ensure your project gets it right first time, get in touch today.


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