OUR "PEOPLE ALSO ASK ABOUT" SERIES
By Ben Parrot - Landscape Gardener & Amateur Geologist
Overview
Welcome to our latest article in the "People Also Ask About" series, tailored for DIY gardeners and homeowners who are navigating the challenges of DIY landscaping and gardening. This series is designed to address the most frequently asked questions, providing you with expert advice and practical tips to renovate your outdoor spaces.
Key Takeaways
Best Drainage Solutions
From 10mm gravel to 20mm gravel sub-base through to non-woven landscaping fabric, we cover some of the best drainage solutions for your gravel feature's installation.
Does water drain through gravel?
Yes, water drains through gravel quickly and extremely well, especially when compared to other surface materials such as soil, bark chippings or concrete. This allows areas that would otherwise be prone to pooling to dry up rapidly, reducing the possibility of water pooling. Find out more about putting Membrane Plastic Under Gravel.
How do you keep gravel from washing away on a slope?
One of the best ways to keep gravel from washing away on a slope is by the installation of a type of paver known as a gravel grid. You install gravel stabilisation grids by anchoring them securely to the ground, which creates a honeycomb structure that effectively holds gravel in place. This mitigates gravel displacement, ensuring durability and stability under all conditions, including heavy vehicular traffic.
Do I need landscape fabric under gravel?
No, it is not compulsory to put landscape fabric under gravel, but for certain applications, such as paths, patios and driveways, it is a must. When positioned beneath inorganic materials like stone chippings, gravel, or sand, the fabric acts as a barrier to weed growth while improving drainage. However, it's not recommended for use under organic mulches like wood chips or bark, which decompose over time. In these cases, the mulch will just form a new layer of soil on the fabric which will foster weed growth.
What do you put under gravel for drainage?
For general landscaping, non-woven geotextile fabric is the most common choice to put under gravel for drainage. Landscaping fabrics support the stones, providing better drainage and filtration, resulting in better soil stabilisation across most applications. With options ranging from lightweight to heavyweight, its felt-like texture is excellent for water management and keeping the chippings separated from the soil, making it a highly beneficial approach to construction. We answer more related questions in What to Put Under Gravel.
Is sand better than gravel for drainage?
No, gravel is far better than sand when it comes to maximising water drainage. This makes it superior in situations where the priority is efficient water movement in areas prone to flooding. Gravel's aeration properties are particularly beneficial for preventing excessive water from adversely affecting plant health.
How deep should gravel be for drainage?
For effective drainage, a gravel layer should be installed in the trench to a minimum depth of 3cm (1 inch). However, a deeper layer is advisable to meet specific slope requirements or to add stability to the stones or drainage pipes that it supports. Ensuring a solid foundation for drainage pipes is key to optimising water flow and preventing potential drainage issues. Find out more in Laying Gravel Tips.
Can I just use gravel for drainage?
Yes, gravel is an excellent material for drainage applications and managing excess water on your property. From limestone soakaways to French drains, gravel is an excellent and cost-effective way to divert water from your property.
Does water seep through gravel?
Yes, water seeps through gravel very effectively due to its porous nature. Gravel's permeability, characterised by its small gaps and spaces, enables water to pass through it very efficiently. This is why gravel is an ideal choice for drainage systems, including French drains, where its main function is to aid in the swift re-direction of water away from specific areas.
Do I need drainage under gravel?
No, gravel driveways do not need a channel drain, unlike concrete driveways. However, where there is a lack of slope, the best practice involves installing a land drain or twin-wall beneath the gravel, which forms a French drain system to efficiently channel water to an appropriate discharge point or local stormwater drain. Get insights into Installing a Gravel Driveway, step-by-step.
Summary
In this article, we explored the benefits of using geotextile fabric under chippings, the drainage capabilities of gravel compared to sand and the importance of landscape fabric under gravel. Our goal is to empower you with the knowledge to make informed decisions that will improve the longevity and success of your garden and drainage projects.
