How to Choose the Right Concrete Grade

First of all, understanding the numbers behind concrete grades is a piece of cake.

What the Grade Numbers Mean

In terms of workability the ‘C’ number refers to the compressive strength of the concrete in newtons per square millimetre after 28 days. Thus C10 is the weakest grade of concrete that is commonly used, and C35 would be one of the higher workability mixes used for domestic and commercial groundwork. However, the higher number means a more dense and stronger mix, which can be more expensive.

Light Work and Blinding Layers

C10/ C15 are used for low load applications. These would be used for blinding to foundations, filling around underground drainage etc. Also for setting fence posts. The above would not be used for applications that are going to bear load or have traffic going over them.

Paths, Drives, and Slabs

For garden paths and domestic footings, such as houses, a C20 grade is usually sufficient. However, for a driveway with regular use by cars, a C25 grade would be more suitable. A C30 grade would be more suitable for a driveway where vans and lorries occasionally use the driveway.

Foundations and Structural Pours

Extension foundations are generally designed using a C25/C30 concrete, depending on specific design criteria. For fully-reinforced structural work a C35 or higher would be specified, allowing for possible freeze-thaw cycles in exposed conditions.

Placing Your Order

When ordering concrete in Stroud for a project it is wise to check the required concrete grade with the structural drawings or contact the engineers for the project, to avoid ordering the wrong concrete and therefore paying for extra strength that is not needed.

There is more on Concrete Stroud at https://www.monstermixconcrete.co.uk/concrete-stroud/.

Getting the grade right from the start will save you money in the long run and will prevent many problems associated with poor quality concreting.