Natural Stone Paving Slabs FAQs

FAQs — Natural Stone Paving

Why choose natural stone?

1. What are the benefits of choosing natural stone paving slabs?

Natural stone paving slabs are a timeless material and have been used for centuries. Their aesthetic appeal and longevity make them a popular choice for residential and commercial patios and driveways.

Aesthetic appeal: Natural stone provides a unique, elegant look that is unmatched by synthetic materials. Each slab has distinctive colour variations, textures and patterns, adding character and style to any outdoor space.

Durability and longevity: High-quality natural stone is incredibly durable and can withstand harsh weather conditions without deteriorating.

Increases property value: Due to its aesthetic appeal, high-quality natural stone can increase the value of your property.

Low maintenance: Natural stone is fairly low maintenance. It needs only occasional cleaning maintain its beauty and functionality, and cleaning is quicker if you’ve also had your paving sealed.

Versatility: Available in a variety of types such as granite, limestone, sandstone and slate, natural stone can be used in a wide range of applications, from garden paths and patios to driveways and pool surrounds.

2. How do I choose the right type of natural stone for my project?

Choosing the right natural stone for your paving project depends on several factors. Here are some key considerations to help you make the right choice for your project:

Aesthetic fit: Natural stone comes in a variety of colours, textures, and finishes. Choose a stone that complements your property and design choice.

Durability needs: Different types of stone have varying levels of durability and resistance to weathering. For instance, granite and basalt are extremely hard and durable, making them suitable for high-traffic areas. Limestone and sandstone are slightly softer but usually have a much wider colour choice.

Maintenance requirements: Some natural stones require more maintenance than others. For example, sandstone is more porous and may need regular cleaning to prevent staining. Slate, while less porous, can still benefit from sealing to maintain its appearance over time. Find more information on cleaning natural stone paving and whether sealing your paving is necessary.

Your budget: Price is often an important factor. Natural stone can vary significantly in price but bear in mind that, whatever the cost of the material, installation costs remain the same, so we’d always recommend stretching the paving material budget as much as possible to maximise your investment.

Environmental impact: If sustainability is a concern, consider where and how the stone is quarried. Local stone that doesn’t require long-distance transportation offers environmental benefits in reduced carbon emissions.

Installation constraints: Some stones are easier to install than others. The weight and size of the stone can affect installation methods and costs. Discuss options with your contractor to understand what installation entails for each type of stone.

Slip-resistance: Especially important for areas like pool surrounds or outdoor kitchens, choosing a stone with good slip-resistance is crucial.

Sample viewing: Always view samples of the stone in different light conditions before deciding. This can help you get a true feel for how the stone will look in situ.

3. How long will a natural stone patio last for?

A natural stone patio can last for over 25 years if it is made from high-quality, hard stone that has been professionally installed and is regularly maintained.

4. What is Indian sandstone?

Indian sandstone is popular in building and landscaping projects around the world. It is known for its durability and natural beauty. Its significantly lower cost, compared to that of indigenous natural stone in Europe and the UK, has also contributed to its popularity.

The rich colour variations of Indian sandstone, which range from browns and beiges to more exotic hues like reds, greys, and greens, are the result of mineral content and sedimentary layers laid down when the stone was formed and are part of its appeal. Indian sandstone is often chosen for its resistance to weathering and its ability to retain its appearance over time, making it a popular choice for external paving slabs.

5. How much is Indian sandstone per m2

The cost of Indian sandstone per square metre typically ranges from £25 to £35. This price can vary depending on factors such as the quality of the stone, the supplier, and how it's packaged. Given these variations, it's important to compare samples before making a purchase, to ensure that the quality of the material is in line with your expectations. Find out more about the cost of natural stone paving, including how to make a design look more expensive.

6. How is Indian sandstone paving made?

Riven sandstone is extracted and processed with a combination of traditional craftsmanship and heavy machinery. Initially, large blocks of sandstone are separated from the quarry bed by machinery. These blocks are then further split into large, rough sheets.

Once the sheets are prepared, they are roughly cut into oversized slabs. Precise measurements for the final product are marked using a metal template, and these are then cut to the exact dimensions required with chisels and hammers.

After achieving the desired shape and size, the slabs undergo a calibration process using machines to ensure they are of uniform thickness.

In the case of sawn sandstone, the initial blocks are sliced into thin slabs using large block saws. The edges of these slices are then further cut to precise dimensions. Finally, a surface finish is applied to enhance the stone's natural aesthetics.

7. Do natural stone paving slabs require sealing, and how often?

Sealing natural stone paving slabs is recommended to protect them from staining and weathering, especially for porous materials like sawn sandstone and limestone. London Stone recommend Dry Treat Stain Proof as this is an impregnating sealant that penetrates deep into the stone without changing its appearance. See our blog for more information on different types of paving sealant.

8. How many paving slabs do I need?

Measure the area: First, measure the length and width of your patio area in metres. Multiply these two numbers together to get the total area in square metres.

Determine slab size: Find out the size of one patio slab by multiplying its length and width in centimetres. This gives you the area that one slab will cover.

Calculate the number of slabs: Divide the total area of the patio by the area covered by one slab. This tells you how many slabs you'll need.

Include extra for waste: Add an extra 10% to your total number of slabs to account for any cuts, breaks, or installation mishaps.

Alternatively, for our paving, use the paving calculator on our product pages. Enter the area measurement you require and toggle between the “m2” and the “ea” option. You can then see how many slabs will cover the area.

Design

1. Natural stone patio ideas

Before laying can commence, a patio or any type of paved area needs to be designed. Depending on the complexity of the project, this may need to be done by a landscape professional. It’s worth remembering that it’s not just about how the finished patio looks. Careful consideration needs to be given to drainage, sub-base and any specific site conditions that might affect the structural stability of the patio.

If you are looking for inspiration for your finished patio, visit our Garden Design Ideas pages and take a look at some of the incredible gardens that have been designed and built using London Stone paving materials. You’ll also find plenty of inspiration in the Garden Design section of our blog, including a round-up of design details for sandstone patios.

2. What factors should I consider before designing a natural stone patio?

Purpose and functionality: Define the primary use of the patio, whether it's for dining, entertaining, relaxing, or a combination. This will influence the size, layout, and features you might include, such as seating areas, a fire pit, or outdoor kitchen.

Location: Choose a location based on exposure to sun and shade, proximity to your house, and views. Consider privacy from neighbours and protection from elements like wind. Remember that north-facing patios will be much more susceptible to algae and, as a result, will need much more maintenance.

Size: Determine the size needed to comfortably accommodate your furniture and the number of guests you anticipate hosting. Ensure there's enough space for people to move around easily.

Materials: Some stones are more resistant to weather, while others may require more maintenance, so select materials that not only match the style of your home but also fit the climate of where you live.

Design aesthetic: Consider the style you want to achieve. Natural stone comes in various colours and textures that can complement a rustic, modern or traditional decor.

Landscaping: Think about how the patio will integrate with your existing landscaping. Consider incorporating elements like built-in planters, garden paths or water features.

Budget: Set a budget early in the planning process. This will help guide your material choices and design complexity. Remember to include costs for preparation, materials, installation and future maintenance.

Drainage: Ensure the patio is designed with a slight slope away from your house to prevent water accumulation. Proper drainage is essential to protect both the patio and your home’s foundation.

Longevity and maintenance: Choose durable materials and a design that you will enjoy for years to come. Consider the amount of maintenance you are willing to undertake to keep your patio in good condition.

Maintenance

1. How do you clean natural stone paving slabs?

Regular Regular sweeping: Stains from organic matter can be stubborn and difficult to remove. We recommend that you sweep your patio regularly to prevent leaves and debris from breaking down and staining the slabs.

Deep cleaning: Use a jet wash correctly twice a year and give your patio a thorough clean. Excessive jet washing is not recommended as the water pressure can damage the surface of the stone.

Stain removal: Treat specific stains like oil or grease promptly with an appropriate chemical cleaner because, the longer a stain is left, the more difficult it will be to remove.

2. How to clean limestone paving effectively:

Avoid acid: Never use acid-based products on limestone, as they can cause serious and irreversible damage.

Regular maintenance: Like other natural stones, limestone should be swept regularly to prevent debris from causing stains.

Deep cleaning: Use a gentle, non-acidic cleaner and a soft brush or a low-pressure wash a few times a year to keep the limestone looking its best.

Sealing

1. What does sealing a patio do?

Sealing a patio with an impregnating paving sealant helps prevent water and dirt from being absorbed into the slabs, which can cause ingrained stains. It's important to note that sealing is not grime-repellent—the surface of the stone can still get dirty. However, sealing makes stains much easier to remove, helping to maintain the appearance and longevity of the patio.

2. Does sandstone paving need sealing?

Sealing sandstone paving is generally beneficial, though not always necessary depending on the type and location of the stone. All types of sandstone, whether six-sided sawn or naturally riven, can be sealed.

Riven and tumbled sandstones, which are more robust, may not require sealing unless they are in high-traffic areas or north-facing gardens, where they are more exposed to moisture and wear.

Sawn paving, on the other hand, has open pores due to the cutting process, making it more susceptible to staining.

Therefore, it is recommended always to seal sawn sandstone to protect against stains and maintain its appearance. Our guide to sealing explains the different types of sealant and will help you decide whether you need to do this.

3. When to seal sandstone paving?

Sealing sandstone paving is an important step to protect it from staining and weather damage. Here are some brief guidelines for when to seal sandstone paving:

Pre-installation: If possible, seal the sandstone before it is installed. This can provide an even coat and protect the stone as it is being laid.

Post-installation dry-out period: If pre-installation sealing wasn't done, it’s crucial to allow the sandstone to completely dry out after it's laid. This usually means waiting for a period that can vary depending on the climate, but typically a few days of dry weather will suffice. This waiting period ensures that no moisture is trapped within the stone, which could lead to damage if sealed in.

Weather considerations: Always choose a dry, warm day for sealing the sandstone. Avoid rainy or very cold days as the sealer may not set properly.

4. Do you need to seal all types of stone patio slabs?

While sealing stone patio slabs can extend their lifespan and enhance their appearance, not all types of stone require sealing. It depends on their porosity, usage and location. Here's a general guideline:

High porosity stones: Stones like sawn sandstone and limestone are highly porous and generally benefit from sealing. This prevents water absorption that can lead to staining, frost damage, and algae growth.

Hardy stones: Certain types of stone like riven and tumbled Indian sandstones, as well as granite, are naturally more resilient and less porous. These stones can often go unsealed, especially in low-traffic areas and south-facing gardens. However, even these hardy stones can benefit from sealing in certain situations, such as in high-traffic areas or in places exposed to harsh weather conditions.

Aesthetic reasons: Some people choose to seal stones to enhance their colour and finish, even if it's not strictly necessary for protection. Sealers can give the stone a wet look that some find appealing, or simply enhance the natural colours. Colour-enhancing sealant is often used to retain the deep tones of Black limestone.

Installation

1. How to lay natural stone paving

Whether you want to lay Indian sandstone, granite, slate or limestone, the process is quite similar. Discover more in our detailed paving installation guide and our instruction videos on laying riven sandstone and laying sawn paving.

In the meantime, here’s a brief overview of the process of how to install paving slabs:

Preparation of base:

Excavate the area to a depth of about 100-200 mm.

Lay a sub-base of crushed stone or hardcore up to 100 mm thick and compact it using a plate compactor.

Create mortar mix:

Prepare a mortar mix of sand and cement (ratio of about 5:1) with water to a workable semi-dry consistency.

Laying the stones:

Start from a corner or edge. Apply a layer of mortar to the sub-base and then place the stone slabs on the mortar. Use a rubber mallet to tap them into place.

Ensure each stone is level and maintain consistent joint widths between them using spacers if necessary.

Cutting stones:

For edges and corners, measure and cut stones as needed using a wet saw or an angle grinder.

Filling joints:

Once all stones are laid and the mortar has set (typically after 24 hours), fill the joints with a pointing mortar.

In our blog you’ll find hints, tips and video on how to lay Indian sandstone.

2. What mortar mix for laying Indian sandstone?

For laying Indian sandstone and for paving installation in general, the optimal mortar mix is 1 part cement to 5 parts sharp sand, with just enough water added to achieve a semi-dry texture. To confirm you've added the correct amount of water, test the mortar by squeezing a handful into a ball. If it holds together without crumbling, the consistency is right.

3. How much to lay Indian sandstone?

The cost of laying Indian sandstone paving in the UK can vary, based on several factors, including the area of the country. Prices are generally higher in London compared to the Midlands, for example. More experienced contractors might also charge more, and the overall cost will also depend on the amount of preparation work required. To ensure you get a fair price, we always recommend getting at least 3 quotes.

4. How to cut limestone paving slabs

1.To cut limestone paving slabs, you’ll need a diamond blade saw.

2.First, clearly mark the cut line with chalk or a pencil.

3.Place the limestone on a stable surface and ensure it’s securely supported.

4.Use the diamond blade to slowly and carefully cut along the marked line.

5.Cutting limestone is generally similar to cutting other types of stone, but it’s important to note that limestone is softer than materials like granite or porcelain, so it requires less pressure during cutting.

6.The softness of limestone also means that it can chip or break more easily under rough handling, so a steady, controlled approach is crucial to achieving a clean cut.