How to Lay a Patio FAQs

FAQs — How to Lay a Patio

Preparation before laying

1. Check the slabs before laying

All natural stone slabs will contain variation in colour, shading, veining and other characteristics. Care should be taken prior to installation to ensure that variation is evenly distributed across the area to be paved. If multiple crates or packs are ordered, all crates should be opened and sorted to ensure an even distribution of variation. Porcelain will also display variation across different batches, so the same applies.

We always recommend that customers check their slabs before they start laying them because, unfortunately we can’t replace or exchange slabs due to natural variation or once they have been installed.

2. What is the best time of year to install paving?

Paving can be successfully laid at any time of the year; however, weather conditions play a crucial role in the installation process. It's important to check the weather forecast before beginning your project. Avoid starting the installation if heavy rain is expected, as it can weaken the bedding layer. Similarly, avoid laying paving if temperatures are expected to drop below 4°C during the mortar curing period, as this can prevent proper setting. Find more information on laying paving in wet and/or cold weather on our blog.

In contrast, extreme heat can cause mortar to dry too rapidly, leading to cracking. Planning your installation around mild and dry weather conditions is ideal to ensure the longevity and durability of the paving.

3. Has sawn stone got a top and bottom or can I lay it any way round?

On sawn stone, generally, the more textured side is on top. For example, the top might be sandblasted. If it’s sawn six sides and hasn’t been textured, the top will be the better-looking side. Calibration marks, if any, will be on the bottom. Also, if you have taken advantage of our paving sealing service, the top of the stone will be sealed and not absorb any water, whereas the bottom will.

4.Which way up should I lay my riven sandstone? Does it matter?

There is a top and a bottom to all natural stone slabs. The top will always be the better-looking side. With riven sandstone, the top will have a larger, flatter surface and the edges will taper in slightly towards the bottom of the slab. If in doubt, just get in touch and we will be happy to assist.

5.Any advice before I start laying the paving slabs?

Open and mix pallets of stone before laying. Do not just lay from one pallet at a time. Laying from a mix ensures an even distribution of the natural variation and colour. It also gives the opportunity to spot any pieces that you’ll want to leave for cuts and wastage.

6.Are my patio slabs ready to be installed on delivery?

In most cases, yes. However, it’s worth remembering that our paving slabs are stored outside, so they can arrive with residual moisture, and they will occasionally need cleaning prior to installation. If you are planning to seal your paving on site, the stone needs to be allowed to dry beforehand and we would recommend unpacking and cleaning the stone prior to sealing.

7. What thickness should the sub base be for a driveway or patio?

The thickness of the sub base for any paving installation depends on the expected usage. For a driveway, which can be subject to vehicle traffic, a subbase of 200mm of MOT Type 1 is recommended to ensure the longevity of the driveway. For a patio, which usually does not bear vehicle traffic, a shallower sub base of 100mm of MOT Type 1 is sufficient. Proper sub base specification and installation is crucial for the longevity and stability of any paved area. Watch our video to see how to install a sub base.

Patio Installation

1. Do you offer an installation service?

No, we like to focus all our efforts on supplying the best-quality natural stone paving we can. However, you can use our Connect service to find a garden designer or landscaper in your area. As with any project of this nature, please ensure that you check companies’ portfolios carefully, to see examples of previous work, and obtain alternative quotations before you agree to any work taking place.

We highly recommend using a professional to carry out your landscaping installation. This will usually be a contractor who is registered with a professional association such as the APL or BALI.

Get a flavour of what a professional job entails in Granite Paving Installation – How a Professional Does It.

2. Can paving be installed over an existing driveway or patio?

We do not recommend laying new paving on top of an existing patio or driveway. The condition and suitability of the underlying sub base are crucial for the stability and longevity of the paving, and these factors can be uncertain with existing installations. Installing new paving is a significant investment, so it's important to start with a solid foundation. This typically involves removing the old paving material and preparing a new sub base to ensure the best possible results. For detailed steps on proper installation, please refer to our patio installation guide.

For more information, check out Laying Slabs on Concrete.

3. Can I install my stone in the rain?

When installing sealed stone, if carried out in the wet after freshly being sealed, the force of the mallet can push moisture into the stone and compromise the sealant. This should therefore be avoided. It may also have detrimental effects to the bedding materials although your installation professional should be able to best advise on this. Discover more in our Tips for Laying Stone in Winter.

4. Does light-coloured stone need to be installed differently?

On light-coloured paving materials, use a white rubber mallet to tap them down or wrap a clean rag around a normal mallet. This prevents rubber marks getting transferred to the paving material, which can cause unsightly stains that are difficult to remove. It is also advised for some specific stone to use white cement and river-washed sand (see individual product guides for further information).

5. Can natural stone paving be butt-jointed?

We strongly advise against this. Pointing is an important part of paving construction and provides stability for the paved area. Natural stone also has dimensional tolerances which make it impossible to achieve an even finish by butt-jointing. Butt-jointing leaves gaps, albeit tiny ones, between slabs and so it can also encourage weed growth and leave the paving vulnerable to damage from freeze/thaw action. Discover more on this and related subjects in our blogpost on laying Indian sandstone.

6. How do I install stepping stones?

Stepping stones should be installed the same way as the main patio: on a compacted MOT type 1 sub base with a full bed of sand and cement mortar. Because stepping stones are usually exposed on all sides, we would recommend installing an angled haunch on all sides of the stone to prevent any lateral movement.

7. Can I install natural stone using a pedestal system?

Pedestal systems are often used where weight is an issue: for example, on balconies. We recommend that stone is a minimum of 50mm thick, no larger than 600x600mm, and that you also place a central support in addition to the edge/corner pedestals.

Alternatively, we sell a range of porcelain products which are ideally suited for a pedestal installation, due to being only 20mm thick and lighter than natural stone. You also do not need a central support when using porcelain on the smaller sizes; you only need extra supports in the middle of each long edge on the 1194mm size slabs.

Pointing, jointing and grouting patio slabs

1. What size should pointing gaps be?

For riven paving we recommend a minimum pointing gap of approximately 10mm. For sawn stones, we recommend a minimum gap of around 5mm. Any dimensional differences in the slabs should be allowed for in the joints, to give you an even finish overall.

2. How should I point my paving?

Pointing is an important part of a patio installation and affects both the durability and appearance of the finished surface. Find out more about How to Choose Pointing in our blog.

Here’s how to point your paving using alternative methods to traditional cement-based mortars. For more detail, visit our Pointing a Patio - 5 Tips for a Professional Finish.

Choose the right product: opt for ready-to-use grouts or resin-based sweep-in compounds, which are excellent for paving, due to their durability and ease of application. These products are less prone to cracking and can better withstand weather changes.

Find out why GftK is one of our favourite brush-in grouts.

Prepare the joints: Before application, ensure that all joints are clean, dry and free from debris. The depth of the product in the joints should be consistent, to ensure a uniform appearance and structural integrity.

Applying the product: For grouts, mix according to the manufacturer's instructions and apply with a grout float, pressing firmly to fill the joints completely. For resin-based sweep-in products, pour the compound over the paving and use a broom to sweep the product into the joints, ensuring they are filled entirely.

Cleaning up: Sweep the surface with a soft brush to remove excess material. Some resin-based products may require a light misting of water to activate the bonding process, so follow the manufacturer's guidelines closely.

Curing time: Allow ample time for the product to set and cure, according to the product specifications. Avoid walking on or stressing the paved area during this period, to ensure the best results.

Cutting natural stone and porcelain paving

1. How do I safely cut paving slabs?

Cutting paving slabs requires careful handling to ensure safety and precision. Follow these safety guidelines to protect yourself and achieve the best results:

Wear protective gear: Always wear appropriate safety equipment, including safety goggles, dust masks, ear protection, and sturdy gloves. This gear will protect you from flying particles, noise, and any accidental slips of the tool.

Use the right tools: Employ a cutting tool that is suitable for the type of material you are working with. Diamond-tipped blades are generally best for most paving slabs, due to their durability and precision.

Secure the slab: Make sure the paving slab is securely positioned on a stable and flat surface before beginning to cut. Use clamps if necessary, to prevent the slab from moving.

Mark your cut: Use a chalk line or a pencil to clearly mark where you intend to cut on the slab. This guide will help you keep the cut straight and reduce mistakes.

Use water suppression: If using a power saw, use water suppression techniques to reduce dust. This not only keeps the work area clean but also helps keep the blade cool and reduces the risk of dust inhalation.

Check the blade: Before starting, ensure the blade is in good condition and securely attached to the tool. A worn-out or loosely attached blade can be dangerous.

Operate at a consistent speed: Maintain a steady and appropriate speed while cutting. Forcing the blade too quickly through the material can lead to inaccuracies and potential breakage.

Keep bystanders away: Make sure the area is clear of other people, especially children and pets, to avoid accidental injuries.

Inspect equipment post-use: After completing your cuts, inspect your tools and equipment for any damage or wear. Proper maintenance ensures safety for future use.

2. What’s the best way to cut paving slabs?

To achieve a clean cut and the right finish when cutting paving slabs, it's essential to use the correct equipment. A diamond blade is highly recommended and, if cutting porcelain, use a diamond-tipped porcelain blade.

Additionally, using water suppression is crucial; it helps keep the blade cool and significantly reduces dust production during cutting.

For ultimate precision, consider using a bench saw, which allows for more controlled and accurate cuts. Ensuring you have the right tools and techniques is key to achieving a professional-looking finish on your paving project.

3. Is it possible to cut porcelain paving slabs?

Yes, it is possible to cut porcelain paving slabs, although they are harder to work with than natural stone. It's crucial to use a blade that is specifically designed for cutting porcelain to ensure a clean cut and to minimise the risk of chipping. Blades suitable for porcelain can be purchased from suppliers like London Stone.

Additionally, always use water while cutting, to help keep the blade cool and reduce the risk of the blade overheating and potentially causing injury. It is also advisable to avoid using a 115mm angle grinder for cutting porcelain, as these smaller grinders may not allow the blade sufficient time to cool, increasing the risk of blade failure and injury.

Find more detail in How to Cut Porcelain Slabs.