The Ultimate Guide To Slate Paving

Slate paving has been used outdoors in the UK for centuries, from farmhouse yards in North Wales to Victorian townhouse paths in London. It comes with a character that's hard to manufacture: the dark, layered surface, the slight sheen when wet, the way each slab sits just a little differently from the one next to it. It also happens to be one of the more practical natural stones for outdoor use: non-porous, frost-resistant, and low-maintenance once laid correctly. This guide covers everything you'll need to make a decision about slate paving: costs, types, colours, performance in the UK climate, installation basics and long-term care. If you have a question that isn't covered here, our team is on hand to help.

Slate paving: at a glance

Slate paving is natural metamorphic rock, which is quarried and cut into slabs for outdoor paving.

What is slate paving?

Slate is a fine-grained metamorphic rock formed under intense heat and pressure over millions of years, mainly from clay and volcanic ash. When quarried and cut into slabs, it produces a dense, layered surface with a naturally cleft texture; what most people recognise as the characteristic “flagstone” surface of Welsh slate paths and country garden floors.

Unlike sandstone, which is sedimentary and relatively porous, slate is essentially impervious to water. That density is what gives it its frost resistance and low-maintenance credentials too. It's also what gives it that particular weight and solidity underfoot, lending a quality that feels different from manufactured concrete or porcelain alternatives.

In garden paving, slate typically comes in riven (split along natural cleavage lines, giving a rough, irregular surface) or sawn (cut flat with a blade) finishes. Westminster Stone's slate paving range covers both.

Types of slate paving slabs

Though you might think you know what slate looks like, actually not all slate is the same, and there are several different types. The quarry it comes from has a significant effect on how it performs and how it looks, and it's worth knowing the differences before buying.

Westminster Stone's slate range is primarily sourced from high-quality, well-established quarries. If you're unsure which type is right for your project, order a sample to compare the finish and density in your own garden before ordering.

How much does slate paving cost?

Slate's reputation for being expensive isn't really deserved. It sits in the mid-range for natural stone paving (more than basic concrete, less than premium limestone or Yorkstone), and it tends to earn that cost back over time through very low ongoing maintenance and a lifespan that stretches across decades rather than years. Due to its excellent longevity and durability, the cost-benefit ratio of high-quality slate paving is exceptional.

At Westminster Stone, slate paving ranges from £40-£70 per square metre and lasts for decades. The beauty of premium natural slate is that it retains its structural integrity and elegant appearance throughout its entire lifespan. Whilst it may feel like an upfront investment, you won’t have to worry about replacing your outdoor paving for years and years. 

For a more precise quote, get in touch with our team, or use the coverage calculator on any product page to work out exactly how much stone you'll need.

What colour is slate paving? 

The beauty of slate is that it naturally comes in a range of beautiful, rich colours, like dark greys, blacks, and silvers. 

Whether you prefer dark colours featuring tones of grey like our Amazon Grey Slate Paving, or blue/black slate like our Amazon Black Slate Paving and for lighter shades of grey that feature rusty hues take a look at our Amazon Carnival Slate.

If you're after cream, buff, or terracotta tones, you'll want to look at sandstone or limestone instead.

Is slate good for outdoor patio paving?

Yes, slate works really well as patio paving, with a few things worth knowing beforehand.

The riven texture that most slate slabs have gives them natural grip, which is useful on a patio where you're moving between inside and outside in all weathers. Slate doesn't absorb water, so spilled drinks, bird mess, and general outdoor grime tend to sit on the surface rather than penetrating it.

The main consideration is colour. Slate patios look best with planting, furniture and architecture that suit dark tones: think dark timber decking, rendered walls, black ironwork, green planting. Alongside a pale brick Victorian house or buff-coloured render, the contrast can work very well.

Slate also gets warm in summer sun, like any dark-coloured surface. In the UK that's rarely a problem, but it's worth noting if you have a particularly sun-exposed south-facing terrace and plan to use it barefoot.

Does slate paving fade or scratch?

Fading is not a big concern with slate paving. The dark tones in slate come from its mineral composition, not from a surface coating or pigment, so there's nothing to bleach out in UV light. You may notice very minor colour changes over many years (like a slight greying in certain lights, or where iron minerals in the stone react slowly with air), but it's subtle and happens slowly. A good stone sealer will slow this down even further.

Scratching is a different matter. All natural stone can be scratched: the question is how visible the marks are and how long they last. On slate, a fresh scratch leaves a pale, chalky-looking mark against the dark surface. It looks worse than it is: within a few weeks of exposure to rain and foot traffic, most surface scratches become barely visible as they weather in.

Dense slates (particularly Welsh and Brazilian) hold up much better to scratching than softer Indian or Chinese variants. This is worth factoring in if you're paving a high-traffic area like a path or courtyard. If in doubt, talk to our experts about which slate specification suits your situation.

Does slate paving get hot?

Dark paving, as any dark-coloured paving, absorbs heat from the sun, and slate is dark, so yes, it gets warm in summer. In direct afternoon sun on a hot day, the surface will be noticeably warm underfoot. In the UK, “hot enough to be uncomfortable” is uncommon except during heatwaves, but it's the same story for any dark-coloured paving material, whether that's slate, black granite, or charcoal porcelain.

In practical terms for most UK gardens, it's not a meaningful issue. The warmth fades quickly once you're in shade or the sun drops, and it has no effect whatsoever on the stone's performance or longevity.

Winter is the opposite concern, and slate handles it well. Its non-porous surface doesn't hold moisture, which means it doesn't suffer frost damage in cold weather. It's a reliable all-year surface, which is part of why it remains popular in Wales, Scotland, and the north of England where the climate is harder on outdoor materials.

Is slate paving slippery?

The quick answer: riven-finish slate is not particularly slippery and meets or exceeds the minimum slip resistance required for outdoor use in the UK. The cleft, almost ridged surface gives enough texture to provide grip in wet conditions.

Sawn or honed slate has a flatter, smoother surface and is less grippy when wet; it’s not unusable outdoors, but worth bearing in mind if the area gets a lot of rain exposure or if you're paving around a pool or hot tub where pooling water is inevitable.

Slate's non-porous surface also means it doesn't freeze in the same way that a more porous stone might. Water doesn't soak in and expand during a freeze, so there's no frost-heave or surface degradation. It won't become a sheet of ice simply because it's cold, though as with any hard surface, standing water in very cold conditions can freeze on top of it, so always take care.

How to lay slate paving slabs

Slate paving is laid in the same way as most natural stone paving: that is, on a compacted sub-base and mortar bed. 

The main thing to bear in mind is that slate's non-porous surface means it won't bond to mortar in the same way that a more absorbent sandstone would. A bonding primer or slurry on the back of each slab before laying makes a big difference.

1. Excavate to approximately 150-200mm depth. Lay and compact a granular sub-base (MOT Type 1). This is the structural layer, so don't skimp on it!
2. Lay a semi-dry mortar bed (4:1 sharp sand to cement). Level it before placing slabs.
3. Apply a PVA bonding agent or slurry mix to the back of each slate slab immediately before laying. Slate's low porosity means a dry slab on a dry mortar bed often won't bond properly long-term.
4. Place slabs on the mortar bed and carefully tap level with a rubber mallet. Use spacers for consistent joint gaps. Maintain a slight fall away from buildings for drainage.
5. Leave new slate paving for at least 24-48 hours before walking on the paving. Don't rush this, as movement at this stage can disturb adhesion.
6. See the pointing section below for how to fill the joints.

How to cut slate paving

In order to make the most of slate paving and achieve the appearance you love for years to come, you’ll need to accurately cut your paving slabs. Follow these steps;

Prepare 

1. Soak your slate paving slabs in water or use a water attachment on your cutter to prevent excess dust when cutting. 
2. Safety first! Ensure that you use a mask, gloves and goggles to reduce the risk of injury.
3. Ensure you have a very flat and hard surface to work on and a well-ventilated area.   

Cut 

1. Create a straight guideline on the slate to help you when it comes to cutting. Using a ruler and pencil, simply draw a line across the slate 90° to the edge of your slab. 
2. Ensure you use an angle grinder or circular saw with a diamond-tipped blade to retain the brilliance of your slate.
3. Place the blade along the line you created in step 1 and begin to cut. Always start cutting from the thickness part of the slate slab to prevent cracks or breakage. 

How to point slate paving 

Pointing your slate paving not only looks beautiful and adds an elegant touch, but also provides a waterproof seal within the joints of your paving slabs. Pointing protects them from inclement weather conditions and prevents water damage in these joints. 

Additionally, pointing your paving slabs ensures that they can easily expand and contract when exposed to extreme weather conditions, without damaging adjacent slate slabs. 

Here are our top tips for pointing your slate paving; 

1. Hose down your patio slabs to ensure that any debris or dirt is completely removed. This layer of water also enables the grout or sealant to adhere more readily and makes your job a little easier. 
2. Ensure there isn't water pooling in the joints before applying a high-quality jointing compound entirely over the slabs to cover them. We recommend Ultrascape Prem-joint or Ultrascape Flowpoint.
3. Sweep or brush the compound into the joints. Ensure that this is evenly distributed to create an elegant look. 
4. Use a trowel or squeegee to firmly press the compound into the joints, ensuring that it is compact and smooth. 
5. Leave to dry for at least 1 hour.
6. Sweep off any excess compound. 

Note - These steps differ depending on which point the product is used, please see our installation and maintenance guide for further details on the installation of these products.

Should you seal slate paving?

In order to enhance the slate’s natural non-slip benefits and improve the appearance of your slate paving, we would recommend using a sealant to ensure its longevity, improve its anti-slip properties and make it easier to clean and maintain.

We'd recommend LTP colour intensifier and stainblock for a deeper richer look, or LTP Mattstone H20 for a close-to-invisible look.

How to clean slate paving

When it comes to cleaning and maintaining slate paving, we recommend the following simple steps;

• Dry sweep the surface to remove any debris and dirt 
• Mix a simple solution of LTP Grimex' and warm water 
• Pour the mixture over your slate paving 
• Use a stiff brush to scrub away any dirt
• Rinse with water 

Following these simple steps, every month or so will ensure that your paving retains its inherent beauty and appearance, throughout its entire life. 

What are the benefits of slate paving?

Aside from the benefits discussed above, slate paving offers an abundance of advantages over many other natural stones. To find out more, read our blog on The Benefits Of Slate Paving. 

Slate Paving Pros and Cons

Browse the Westminster Stone slate paving collection

Westminster Stone's slate paving range spans six distinct products, covering everything from near-black contemporary slabs to warmer, mixed-tone options.

We hope we’ve answered all of your burning questions about slate paving. If you have further questions or require additional information, don’t hesitate to get in touch with a member of our friendly and knowledgeable team.