Last Modified: February 14, 2024

20mm Shingle Gravel

Versatile Decorative Quartz Stones

Shingle gravel close up

By Ben Parrot - Landscape Gardener & Amateur Geologist

Classification:

Stone landscaping material and construction aggregate

Geological name(s):

Varies regionally

Other Name(s):

20mm shingle, gravel shingle, gravel and shingle, pea shingle gravel, gravel pea shingle

Overview

Welcome to the only encyclopaedia for decorative aggregates and landscaping materials. 20mm shingle, also known as 4/20mm pea shingle, is an economical and appealing aggregate widely employed in construction and decorative landscaping. It is commonly used in both domestic and large-scale construction projects. 20mm shingle is comprised of angular and rounded stones, either crushed or natural rock, which are then washed and screened to remove all fines.

Fun Fact: It is also often called 20mm gravel, although there is a distinct difference between gravel and shingle. Gravel, by definition, is small fragments of rock used as aggregate, while shingle is a collection of small stones with one end typically thicker than the other. 

This comprehensive encyclopaedia listing about 20mm shingle gravel, a hardscape and construction aggregate, includes information such as its specifications, benefits, applications and incompatibilities as a landscaping material. It is also a portal to many DIY-friendly resources, including; a list of 'similar to' alternatives, articles for inspiration that cover fundamental design principles, as well as a variety of step-by-step project instructables for building your own decorative aggregate features.

20mm Shingle Gravel Specifications

material

colour

shape

sizes

fall safety

price

Stone

6-20mm

durability

fish friendly

eco friendly

degradability

ph

diy friendly

Non-degradable

Neutral

Material

Quartz or flint stone

Colour

Usually brown, buff, beige and grey

Shape

Rounded to sub-angular

Close up of 20mm shingle. Jpg

Size Range

6-20mm (0.24-0.8")
Pea shingle 20mm, 20mm pea shingle, 20mm shingle gravel, gravel shingle 20mm, 20mm gravel pea shingle

Fall Safety

Unsuitable for play areas

Price

Economical

Durability

High

Fish Friendly

Yes

20mm pea shingle close up. Jpg

Eco-friendly

Yes

Degradability

Non-degradable

pH

Neutral

DIY-Friendly

Yes

20mm pea shingle gravel. Jpg

Benefits

Aggregates like 20mm shingle are economical, highly durable and offer many benefits in landscape design and construction. Shingle gravel possesses a natural colour palette, with a neutral pH and rounded to angular shape. When used as a decorative aggregate, they require minimal maintenance and provide an aesthetically pleasing, coastal look with a versatility that complements various themes, from rustic to contemporary. It's also functional, offering excellent weed-suppressing and drainage properties.

20mm shingle gravel's versatility doesn't end there. In construction, it outperforms at a multitude of applications, with its varying weights and sizes able to accommodate many different construction applications and hardscape design needs.

  • Inhibits weeds
  • Improves drainage
  • Hard-wearing
  • Eco-friendly, sustainable
  • Low-maintenance
  • Moisture retention
  • Versatile all-rounder
  • pH neutral
  • Transform spaces fast
  • Safe for aquatic life
  • Root protection
  • Easy to lay

Applications

Shingle gravel is renowned for its multipurpose use in decorative hardscaping and construction applications. It's commonly used in gardens and landscapes as an economical ground cover and a practical top layer in flower beds and planting borders. Further, because it is relatively easy to walk on, it makes an ideal material for a garden path, patio or driveway.

As a construction aggregate, this type of angular pea gravel type is very effective as pipe bedding and for use in drainage applications. It can be used as a base material for roads and as a sub-base for other landscaping elements, as it provides a strong foundation when compacted. Gravel shingle is also used in the production of concrete and asphalt, general concreting and floor screeds.

In the following section, we list many common 20mm shingle gravel uses, although it is not exhaustive. Wherever there is a hyperlink beside an item, an article from Outdoor Aggregates about the topic is available.

20mm gravel driveway

Inspiration and Informational Articles

DIY-Friendly How-To Guides

Need to work out how many stone chippings your  project needs? Try our free gravel calculator.

Other Applications

Some other excellent applications for 20mm shingle gravel include:

  • Base for terrace, patios or outdoor seating areas
  • Pebbledashing
Crushed stone mulch garden

Unsuitable For

The following list represents the kinds of applications that shingle gravel may not be suitable for:

  1. 1
    Areas with fine plantings: If you have creepers or low-growing plants in your garden gravel can make it harder for these plants to thrive, as it may interfere with their root systems as they try to grow.
  2. 2
    High-traffic driveways, due to displacement.
  3. 3
    Erosion control: On steep slopes or areas with significant inclines, the loose nature of the gravel can make it prone to movement which can be problematic on slopes.

Similar Alternatives to 20mm Shingle Gravel

The following is a list of decorative aggregates which are alternatives to 20mm shingle gravel. They may offer you a more suitable variation on the primary colour, a more economical option, or a close substitute for cases where the base material may be unsuitable for the project you are creating, e.g. limestone is not fish-friendly, where slate is.

Name

Colours

Material

Size

Shape

Availability

Price

buff, white

10-20mm (0.4-0.8")

angular

UK, USA, EU

gold, brown

10-20mm (0.4-0.8")

rounded

UK, USA, EU

pale yellow

Quartzite

5-20mm (0.2-0.8")

angular

UK, USA

Tuscan glow chippings

yellow-orange

Marble

15-30mm (0.6-1.2")

angular

UK, USA, EU

golden, brown

Flint

10-20mm (0.4-0.8")

rounded

UK, USA

white

Marble

10-20mm (0.4-0.8")

angular

UK, USA, EU

Under £80

£80-£120

£120-£150

£150-£200

£200-£300

£300+

Maintenance

Raking 20mm pea

Shingle gravel is generally low maintenance, especially when a heavy duty membrane is installed underneath to suppress weeds, with most work limited to raking and the occasional removal of debris. Occasional power washing of the product is advisable to maintain the original colour and prevent algae or moss buildup. Natural quarry materials also may have dust, which should be hosed off with water at the time of installation.

For areas with heavy footfall, such as paths or footpaths, replenishment of chippings may be required over time to maintain depth and coverage. For more on how to clean gravel, read our article: how to clean garden stones.

Purchasing Tips

Flowers growing in a gravel garden bed. Jpg

When purchasing 20mm shingle gravel, consider the size options and quantity necessary for your project. Where available, it is cost-effective to request a sample to assess the stone's colour and quality against your design requirements. Also, consider the different sizes; for instance, 20mm shingle gravel is typically used for driveways and concreting, while smaller 10mm gravel is better suited to footpaths and other tasks.

Using our gravel calculator to get an unbiased estimate for your project needs is one of the best and easiest ways to order the right amount without the risk of shortfalls or over-spending - all you need is a few measurements of the space. Ordering in bulk bags is often more cost-effective than smaller quantities. Also, always ensure you consider the delivery aspects, especially the vehicle access to the site.

FAQs

What is gravel shingle, and what is it used for?

Gravel shingle refers to naturally occurring stones, typically round or sub-angular, used in landscaping and drainage applications. Gravel shingle is used for various purposes, including garden paths, driveways, drainage systems, and as a decorative feature in flower beds and borders.

What is the difference between pea gravel and pea shingle?

Gravel and shingle are similar, but gravel is small rock fragments, while shingle is small stones with one end thicker than the other.

Is pea gravel good for drainage?

Yes, pea gravel is effective for drainage due to its size and shape, allowing water to flow through easily.

What is 20mm shingle?

20mm shingle refers to shingle gravel with a size of approximately 20mm, ideal for driveways, paths, and drainage.

There are many wonderful types of gravel and aggregates available for your project needs. Check them out!

About the author 

Ben Parrot is a landscape gardener and amateur geologist. He is the founder of Outdoor Aggregates, with the mission to create the first encyclopaedia for decorative aggregates. From natural stone through to decorative bark, these aggregates are critical to garden and landscape design, universally.

The problem: There isn't any place where all the different types of decorative landscaping materials and construction aggregates can be found, nor are the specifications of each type readily available. So, enriched by his extensive experience, and inspired by the timeless elegance and raw beauty of stone and rock, etched by nature's artistry over millennia, Outdoor Aggregates was born.