We generally take external drainage for granted. For the most part, if it rains our gardens don’t flood. But poorly designed and installed drainage can lead to flooding at worst, and the unsightly pooling of water on patios and driveways at best. Here, we explain why your new driveway or patio would benefit from the precise planning and accurate drainage calculations that Laytoe’s structural engineers provide.


A driveway needs to slope down towards ground that is permeable or ground that is made of porous materials such as gravel or clay bricks. This ensures that water drains away from the hardstanding – the surface of your driveway where you would park a car. Laytoe would calculate the angle of the slope so that safe drainage could be assured, or put in place.

If our structural engineers discover that the ideal ground conditions for drainage are not present, we will instruct on the installation and position of an appropriate soakaway. Property owners should be aware that a soakaway must not discharge surface water into a foul drain or sewer.


Drainage for a patio goes beyond a slope to direct water away from your home. If you’re planning on a new patio, you need to ensure that this water is removed safely from your property via a pipe or channel that is the correct dimension for your patio and the expected volume of water in your location.

When our structural engineers carry out a site inspection, it isn’t just to advise on the factors that will lead to the accumulation of unsightly standing surface water, it’s also to prevent more pervasive damage to your property’s foundations such as damp.


If you already have a patio or driveway with adequate drainage, but are thinking about changing the landscaping or material used, we would advise that you consider our structural engineering advice before making what could be a costly mistake. The weight, volume and composition of soil, new slabs and pointing might impact on what was previously satisfactory drainage, and you might need to pull up whatever has been laid down. A Laytoe site inspection, before construction, would provide the most suitable drainage solutions for your new patio or driveway.