Last Modified: April 4, 2024

Slate Chippings For Driveways

Exploring The Pros, Cons and costs

Driveway with blue slate chips

By Ben Parrot - Landscape Gardener & Amateur Geologist

Overview

Ever thought of using slate chippings for driveways instead of tarmac or block pavers? Did you know that Welsh slate is one of the most versatile and durable decorative aggregates you can find.

Driveway slate chippings have earned a reputation for being one of the most cost-effective and low-maintenance hardscaping products, with numerous functional and aesthetic benefits. The wonderful darker shade they go during wet weather brings out an eye-catching, natural elegance. Best of all, they are pretty DIY-friendly to install.

A quick heads-up regarding our freshly introduced tool, the 'Pebble Picker', accessible in the sidebar or menu. It streamlines the task of viewing and comparing decorative aggregates, organised by colour and type, for your convenience.

Slate with rockery planters and car

A plum slate driveway with rockery stones.

When it comes to choosing the right type for your driveway, it's important to have access to detailed information about the different sizes, colours and textures available. This article will help you make the best choice for your home. Let's move forward and carefully consider the main factors to keep in mind when choosing to install a loose slate driveway.

Key Takeaways

  1. 1
    Slate Driveway Chippings: A durable and good looking, natural landscape option that also controls unwanted weeds.
  2. 2
    Size Matters: Choosing the right size and shape to suit a driveway is important.
  3. 3
    Economical: Get an approximate costing of a slate chippings' driveway and compare it to other paving alternatives.
  4. 4
    AlternativesSlate can be a sound choice but also less durable than alternatives like gravel.
  5. 5
    Slate Chippings Calculator: Our calculator can give you an accurate estimate of the slate you will need.
  6. 6
    Low-Maintenance: Only requires occasional upkeep to get the most out of your driveway.
Grey chipped slate in a front garden

Benefits of Driveway Slate

Garden slate chippings are simply just beautiful! They add wonderful colour to your driveway or paths, with a variety ranging from light grey, plum, black and green through to the enchanting blue slate chippings, and when they get wet, they also develop darker shades, giving your space a look that varies with the weather.

Cost-effective

Slate is also a very cost-effective material with the average price of 20mm slate chippings coming in around £80-£100 per bulk bag. The costings are listed, below. Therefore, if you intend to install the drive yourself, this could make the average cost a lot lower than most other types of driveways in general. For example, various grey driveway stones are a popular surfacing material, but few options are as cheap and as attractive as grey slate chippings.

Shrubs growing on a slate front garden

Durability

Being a fine-grained type stone with distinct metamorphic rock layering, a slate gravel driveway is resilient as a construction aggregate. Apart from its aesthetic charm, slate aggregate is durable. Its strength rivals that of most stones, ensuring your driveway lasts for years. The exception would be pea gravel and most types of crushed gravel. Due to crushed gravel's angular shape, it is generaly the most hard-wearing decorative aggregate for driveways.

It is important to note that we don't recommend the use of slate mini-mulch driveways as it will deteriorate under the weight of heavy-vehicle traffic.

Plum slate garden with conifers

Eco-Friendly Weed Prevention

Pesky weeds can be the bane of your existence, tarnishing the appearance of your driveway or patio. With a weed fabric laid beneath slate chippings, it reduces weed germination significantly. Laying a heavy-duty membrane also aids water retention, helping your driveway border to retain moisture by cooling the soil, which is beneficial for any adjacent plants or trees.

From a sustainability point of view, slate chippings are not only natural stone, but many types are derived from recycled roofing tiles, like graphite grey slate chippings for example.

Weed growing in blue slate chips

Potential Drawbacks of a Slate Chip Driveway

We have discussed the advantages of slate driveways, but it's important to consider some potential drawbacks.

  1. 1
    A slate driveway has a greater potential for shifting than many gravels or block paving, particularly without proper installation or edging, which can lead to uneven patches that can require a bit more upkeep to stay on top of.
  2. 2
    Thin slate can be brittle, so the size of the slate chippings can have quite a bearing on appearance and durability. If your preference is for very small chips, like slate mini-mulch, it generally doesn't suit a slate for driveway construction. More on this further down.
  3. 3
    While one of the cheapest options, the cost of may be higher than other, more budget gravel options - but not by too much.
Plum blue and grey slate chippings

Costing a Slate Driveway

Checkatrade driveway estimates. Jpg

We always pride ourselves on providing unbiased information, so above are some costing estimates from a reputable British site, Checkatrade. However, from our calculations we are a bit mystified when it comes to the estimate provided for a gravel driveway, which slate chippings would be categorised as. Let's make some calculations based around a standard driveway of 4m length by 2m width, which would be 8 m² in total. According to their estimate, the cost would be between £400- £560. It is unclear whether or not labour is calculated into this figure.

Gravel driveway calculation. Jpg

Click on the image if you would like to use our gravel calculator.

By our own calculations, without labour, the amount of slate chippings required to cover this area, at 5 cm minimum depth, comes in at a grand total of one bulk bag. Add to this approximately 1.5 bulk bags of hard-core, to be on the safe side. Brick edging. 10㎡ of weed membrane. 24 hours hire of plate compactor. With generous over-estimations of prices, a grand total of £365, or £45 per ㎡. That makes it the second cheapest option in their list of alternatives.

  • One bulk bag of slate chippings - £100.
  • One and a half bags of sub-base - £70.
  • 10㎡ of weed membrane - £20
  • Brick edging - £100
  • 24 hours hire of plate compactor - £50
  • Sundries - £25
  • Estimated total -  £365

Therefore, (if you agree with our rough calculations), based on the estimates provided by Checkatrade, the labour cost for building the driveway only accounts for between £35 and £195, or between 1 to 6 man hours. We would warn anyone against expecting the cost of a standard job such as this to come in under 6 hours of labour, not to mention the rest of the costs! Perhaps these estimates are the costs minus the labour. We will have to leave that up to you to decide.

Laying plum slate on weed membrane

Budget Alternatives

With the claim that concrete is £75 – £85 per ㎡  and asphalt is £50 – £100 per ㎡, slate still comes out cheaper. So, while there are many good reasons to choose a slate surface, if budget is a concern, there may be some reasons to consider a few, slightly cheaper alternatives to using slate driveway chippings. The cost of a new driveway depends on its size, the material used and the complexity of the installation. Here are some average alternative driveway costs based on these factors:

  1. 1
    Resin-bound Drives: While Checkatrade say to budget for £80 – £210 per ㎡,  with resin bound gravel kits, the cost per m2 can range from £6 to £12 per square metre at about 15mm depth. This would indicate that they are adding labour cost in this example, but seemingly do not in the case of slate driveways? If you have a concrete or asphalt drive to improve, resin-bound gravel is by far the cheapest option.
  2. 2
    Generic 20mm gravel: If you opted for a generic, 20mm gravel, which you should be able to pick up for between £50-£60 per bulk bag, you will be able to save an extra £5 per square metre over slate.
  3. 3
    Paver or brick driveways: From £32 – £100 per ㎡, customisable shapes and colours, with recycled options as well, can be done cheaper.

Each material presents a unique blend of cost, durability, maintenance and aesthetic value, catering to diverse preferences and budget constraints. Let's take a closer look at some of the gravel alternatives:

Name

Colours

Material

Size

Shape

Availability

Price

varies

varies

14-20mm (0.6-0.8")

angular

UK, USA, EU

purple-grey

10-30mm (0.4-1.2")

flaky, flat

UK, USA, EU

grey

slate

10-40mm (0.4-1.6")

flaky, flat

UK, USA, EU

cream, buff

10-20mm (0.4-0.8")

angular

UK, USA, EU

red

10-30mm (0.4-1.2")

angular

UK, USA, EU

blue

granite

10-20mm (0.4-0.8")

angular

UK, USA, EU

Under £80

£80-£120

£120-£150

£150-£200

£200-£300

£300+

Gravel and Pebbles

Gravel is the most common landscaping material used for surfacing a driveway or walkway. Crushed gravel is super hard-wearing and due to it's angular shape, packs flat to bond the most effectively. On the other hand, slate can be more brittle and prone to deterioration under heavy vehicular traffic. While the look of slate is hard to match, decorative gravels also come in wonderful colours and sizes.

Construction aggregates like pea gravel can provide a rustic look and are often cheaper than slate. There are many other quarried stones which can also offer durability but suit different preferences, but pebbles are not recommended due to their tendency to shift around.

Pea shingle with decorative edging and rockery

Concrete, Cobbles and Pavers

Slate cobble setts are an elegant and durable choice for driveways, offering a unique natural aesthetic with their varied shades of black and smooth, flat surface. While quite expensive in the UK (~ £140㎡ inc VAT), they are known for their strength and longevity as a practical yet stylish option for any property or outdoor space.

Concrete driveways are very durable and can be coloured or stamped to achieve various finishes, although they lack the elegance of slate. Also, they are far more difficult to install, making concrete drives far less DIY-friendly.

Block paving, or decorative brick, is another alternative which comes in a range of designs and patterns. While they might not have the natural charm, they offer design versatility and a different kind of clean looking finish. Block pavers are also more DIY-friendly than concrete.

Paved drive with slate chippings edging

A blue slate driveway with pavers.

Installation Basics

When selecting slate chippings, it is important to consider the application. The colour you choose will impact the feel and overall continuity of your driveway and gardens. That's why it's important to carefully evaluate your objectives to select the best size, as this will ensure your features' durability and aesthetic appeal.

Choosing the Right Size

Slate mini mulch, characterised by its fine texture and measuring 4–10mm in diameter, can be an excellent choice for many applications and garden projects. However, it's important to note that we advise against using slate mulch for driveways due to its tendency to crumble easily under the weight of a car, making it less suitable for such heavy-duty usage.

Choosing the right size aggregates for your driveway

Preparing the ground for laying slate chippings.

While the most likely choices are between 20mm slate chippings, 40mm slate chippings or the larger slate paddlestones, your choice should align with the goals for your driveway. Outdoor Aggregates' first choice would always be 20mm chippings due mainly to their superior bonding and ability to provide the flattest surface after settling. While all sizes can work, you should consider the differing outcomes when choosing the size.

Next, we provide an outline on installing a driveway and how to estimate your project requirements.

1measuring an area for slate driveway

Measuring the ground for laying slate chippings.

The Basics of Laying a Slate Chippings Driveway

Once you're in the garden, laying slate chippings starts with proper ground preparation. First, you will need to measure the area and dig at least 10cm of dirt out, removing any weeds or roots likely to cause future issues. Next, the area must be flattened and a sub-base applied before laying a weed membrane to inhibit weed growth. After completing the sub base, it's time to lay your slate chippings on the membrane. Use a steel rake to spread the chippings evenly, achieving a uniform depth.

We cover the installation of a slate driveway in a step-by-step DIY guide in our article: Installing a Gravel Driveway.

Estimating Materials With Our Online Calculator

Before committing to any outdoor project, you should consider what materials you need and how much you'll require. A plan based on rough estimates can lead to extra expense or an unfinished project. Thankfully, we offer a free online gravel calculator to help you get some tangible numbers to mull over just by inputting your driveway's dimensions. You can even get an estimate of the cost by entering the price per bag.

1pencil sketchpad measuring tape and weed membrane for garden planning

Maintenance Tips

Maintaining the elegance of your driveway or slate chipping path requires occasional upkeep. Over time, dirt, leaves, and other debris tend to collect. This accumulation can affect the appearance and create a substrate for weeds to take hold in. Dirty slate chippings may be cleaned with a gentle rinse of the garden hose. After rinsing, let the slate chippings dry naturally.

1washing slate chips with a garden hose
1cleaning stone chippings with a hose

Replacing and Refilling Chippings

Even with the best care, some wear and tear is unavoidable. The consistent pressure from vehicles and foot traffic can lead to thin spots on your driveway. It's good to keep an eye out for areas where the slate is becoming sparse. By periodically filling the gaps to maintain a consistent layer, you can keep your installation looking great and ensure optimal functionality. This is where having some extra slate chippings on hand can be beneficial.

For more easy maintenance tips to help ensure your feature remains in top-notch condition for years to come, check out our article on how to clean garden stones.

1raking slate walkway

Where to Buy Materials

When considering where to buy slate chippings, start here and then shop local. Many local suppliers offer a range of slate chippings, from blue slate to light grey options. They usually provide delivery of bulk bags, making transport easy. Local suppliers can also offer helpful advice about what's best for your region, ensuring you choose the right type of slate.

Many reputed online retailers offer a vast range of slate chippings and complimentary materials, ready to order. While most lack specifications or detailed descriptions, you may be able to gauge the quality from customer reviews before purchasing. But this is where Outdoor Aggregates has your back.

Purchasing your landscaping materials online has become a breeze, especially with an Outdoor Aggregates membership (coming soon).

1slate rock in a pallet container

Purchasing the slabs for a grey slate driveway.

Summary

Transforming your driveway with slate chippings is a creative and practical choice. These stunning decorative aggregates offer a range of benefits, from weed prevention to long-lasting elegance. Slate chippings' versatility makes them great for decorative use in garden borders, pathways, and even water features that can complement your drive.

After reading this, you are so much closer to attaining a stunning driveway that will lift the look of your place while adding value to your house. So, why wait? Start planning your next project today and harness the beauty and functionality of a slate chippings driveway.

1car parked on slate gravel

FAQs

Is slate any good for a driveway?

Slate chippings can be a very good surface for driveways, as they add an aesthetic that is hard to match and offer excellent drainage properties. At the same time, areas that would experience a lot of traffic, especially from heavy vehicles, may not be suited to slate chipping driveways because they can be crushed and may deteriorate overtime.

What size slate is best for a driveway?

Typically, larger chippings such as green slate 40mm are best, but the best size often depends on personal preferences and the specific use of the driveway. 

Can you use blue slate for a driveway?

Yes. Blue slate is not only visually striking but is also very cost-effective and maintains its beauty over time, making it the most popular choice, followed by a grey slate chippings driveway. 

Is slate rock good for driveways?

Yes, being a hard-wearing metamorphic rock, slate provides durability under most conditions, as long as it's a minimum of 20mm in diameter.

What size chippings for driveways?

For driveways, slate chippings of 20mm to 40mm in size are typically recommended. This size range provides optimal stability and durability, while also ensuring a visually appealing surface.

Are slate chips suitable for driveways?

Yes, in most cases. A well installed, crushed slate driveway combines durability with beauty, making them an excellent choice for driveways. However, slate mini-mulch is not recommended as it is too small. Also, if you are going to have a heavy vehicles on your driveway you may want to consider something slightly more sturdy.

There are many colours and specifications of slate chippings available for planning your driveway project. Check out 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.