the foundations of any successful paving
By Ben Parrot – Landscape Gardener & Amateur Geologist
Overview
Whether for a public pavement or DIY driveway, foundations serve three purposes: they provide essential drainage while offering a stable base for the top layer. It prevents the surface materials from sinking or popping up due to weather changes. In colder climates, the foundation expands and contracts as the soil freezes and thaws. This constant movement of the foundation can lead to significant structural damage if not addressed properly, which is why a sub base is a crucial aspect of engineering and domestic construction processes. Proper preparation is always key to the installation of any landscaping feature’s longevity and functionality.
In this article we bring you all you need to know about the different types of sub-base products, provide you with information about some of the issues when installing a sub base as well as complimentary materials required to successfully lay subbase in your garden. Let’s take your project to the next level!
Key Takeaways
- Foundations: Find out why a sub-base is the backbone of any paving project, from stability to load distribution.
- Materials: Learn what materials you need build a foundation for the prevention of sinking and rut formation.
- Drainage: Effective water drainage under construction projects reduces the risk of water damage and flooding.
- Installation Basics: Find the basic steps for a well-constructed sub-base.
What is a Sub-Base?
Subbase, also called subgrade, is a compacted layer of aggregate material which is laid beneath landscaping features to spread the load of the surface materials and any traffic upon it to the subgrade beneath. A proper sub-base also aids drainage and prevents undesirable settlement and subgrade rutting. It does this by distributing the weight, which prevents sinking, cracking and other types of wear and tear.
Whether block paving slabs, gravel or asphalt on a driveway, patio or pathway, a sub-base forms the backbone of any paving project by providing support that minimises movement and the pressures of freeze-thaw cycles, significantly extending the life of the installation.
What is Subgrade Rutting
Loads are distributed through the paving structure and push down on the sub-base, usually causing subgrade rutting in the wheelpaths. This is because the top layer’s structure flexes downward to accommodate the depressed foundation layer.
When to Install a Sub-Base
Generally speaking, a sub-base foundation is not necessary for most aesthetic features built with decorative aggregates, such as ground covers or gravel gardens. However, when creating any project where traffic will impact the surface, from roads and patios to pathways and driveways, it is necessary to build a proper foundation regardless of the climate or type of material used. Without one, the traffic will quickly cause the surface to distort and deteriorate.