What use is a French Drain?
A French drain is a trench of approximately 6 or 150mm wide (or the width of your spade), approximately twice the depth (i.e. 12 or 300mm). In most cases this will suffice however where there is a large amount of ground water, you may wish to make the trench wider and deeper. A French drain acts as an area where water soaks away quickly. We often recommend them close to the building and not next to the building as this helps to reduce the ground level and it will take any water that is directed at that area away (for example as mentioned where a patio has been placed which aims any rainwater to part of the wall). As mentioned, whilst a French drain is a DIY job it does need some understand of how it works.