Installing a patio is an excellent way to get more out of your garden. A patio can be an area for relaxing and entertaining and acts as a transitional space between house and garden. Patios are low maintenance, hard-wearing, and relatively simple to install. Laying a patio also offers a chance to be creative with design and construction, thanks to the wide variety of available slabs.
We’ll show you how to lay a patio without cement or mortar using the handy pre-mixed.
This guide includes tips on:
Which patio slabs to choose
Safety measures to take when laying a patio
Preparing to lay a patio
How to calculate the amount of sub-base needed
How to lay patio slabs
How to lay patio slabs with mortar
How to point a patio
Patio aftercare
Before getting started, browse our gardens range to stock up on everything needed to lay a patio. You can pick a paving slab to match your garden design in our extensive patio range, plus all the accessories required for installation.
What patio slabs do I need?
There are many factors to consider when selecting your patio slab. Of course, you’ll need to pick a style that complements your existing garden design. Budget, maintenance and durability also affect the choice you make.
To help with your decision, here’s a summary of the benefits and drawbacks of popular paving slab materials:
Porcelain. A popular choice with homeowners, porcelain is durable and low maintenance; although it’s a slightly pricier option, porcelain is algae resistant and less susceptible to staining, making it a smart choice
Sandstone. A natural stone, sandstone is very durable and has a textured surface that can help prevent slipping. With a distinct look, sandstone’s colour won’t fade, although an anti-algae sealant will need to be applied
Limestone. Another natural stone that boasts excellent durability, limestone comes with a smooth finish for modern garden designs. A mid-range patio slab, limestone suits most budgets
Concrete. This type of paving is very affordable and comes in various finishes to suit any garden; go for a minimal flat slab or a textured one to add some character. Concrete is considered less durable than other paving, and you’ll need to apply a sealant to prevent staining and algae buildup
Is laying a patio difficult?
Follow our simple steps, and you’ll find that any DIY beginner can lay a patio. Although the steps involved are simple, this can be a time-consuming process. However, thorough preparation and planning will ensure the project is successful.
Safety measure to take when laying a patio
To ensure you stay safe when laying your new patio, follow these steps:
Patio slabs can be weighty; we recommend working with another person to reduce the strain of lifting and moving the slabs
Always wear suitable footwear and gloves when handling slabs, sand, cement and digging; if you use a wacker plate, wear ear defenders and steel toe-capped boots
Wear a dust mask, protective gloves and safety goggles when mixing and handling mortar mix, cement or Slablayer; you should also follow the manufacturer’s instructions
Wet and dry cement can cause irritation, so handle carefully and cover your skin. Always wash with soap and water if any cement comes into contact with your skin
Before digging, use a CAT tool to ensure there are no hidden pipes or cables. Pipes and cables should be at least 450mm below the surface
Preparing to lay a patio: step by step
Draw a plan
Once you’ve decided on your patio’s location, draw a detailed plan to scale on graph paper. Your plan should include relevant measurements and nearby features like your house and fencing.
Plan your slab placement
Planning your slab placement is entirely down to personal preference. You may want uniform rows of patio slabs or prefer a pattern consisting of different sized slabs. Using slabs from various pallets? It’s good to mix them up to disguise any colour variation.
'Dry lay' the slabs
Having planned your patio, ‘dry lay’ the slabs in your preferred design. This is an excellent way to visualise the finished patio and double-check that your measurements are correct. Then take a photo of the layout for future reference.
Allow for the right joint size between each slab; if your patio will be next to your house, its surface needs to sit 150mm below the damp proof course.
How much sub-base layer do I need for a patio?
Once you’ve planned the layout and location, you need to prepare the sub-layer for the stones to sit on.
Mark the area
Start by marking the area using wooden pegs and a builder’s line or string.
Check the measurements
Use a set square to check the corners are exactly square. As a final check, measure the diagonals, which should be the same length. If they’re not, adjust the edges as necessary.
Calculate the fall
The next step is calculating the necessary fall for your patio. A fall is a gentle gradient in the sub-base that allows proper drainage and ensures water runs away from the house.
The ideal gradient for a non-textured slab is 1:60, a 16mm drop in level per metre. When working with a textured slab, the target gradient is 1:80, with around 12.5mm drop per metre.
To calculate the fall, multiply the ideal fall by the patio’s sloping side length. This gives you the total difference in height between the highest and lowest points. For example, a 4m patio has a fall of 64mm (4 x 16 = 64mm).
Remove the turf
Mark the patio outline with a lawn edger to ensure straight lines, then remove the pegs and string. If you mark the edges on the outside of the string, the extra margin will result in a firmer foundation.
Cut the turf into strips with a lawn edger and remove using a spade. Roll up the turf and save some to fill in gaps between the lawn and the patio.
Calculate the depth
Now you need to calculate how deeply to dig. The depth will vary depending on how you construct your sub-layer and how thick the patio slabs are. For this project, we’re digging a total depth of 175mm to allow for:
100mm of MOT type 1 granular hardcore
25mm of Slablayer
50mm thick paving slabs
Remember to include the necessary fall in your calculations.
Peg out the sub-base
Pegging out the final surface level of the sub-base ensures consistent depth across the dig. The aim is to make sure your sub-base layers reach the top of the pegs. Take a wooden peg, and from the top, mark the finished depth of the hardcore layer.
Hammer in a row of these pegs 75-100cm apart across the highest side of your site, making sure the marked line is level with the earth. Use a long piece of timber and a spirit level to ensure the pegs are level across the row. Repeat this process for subsequent rows while maintaining the necessary fall.
Add the hardcore mix
Add the hardcore mix to reach the top of the pegs; we’re adding the hardcore in 2 x 50mm layers for extra stability here. Add 50mm of hardcore and rake over, so it’s roughly level. Then compact the layer using a wacker plate or a tamper. Repeat this process for the second layer.
Add the slablayer
Now add the Slablayer, raking it out to a depth of 25mm. Use a spray gun to apply water to the Slablayer. Then rake again to level the surface.
How to lay patio slabs: step by step
Once you’ve laid the sub-base, it’s time to lay the patio slabs.
Lay the first slab
The first paving, called the ‘key slab’, is the most important one you lay. It provides a guide for the others, so it needs to be positioned correctly and sit level. The best starting position is the corner at the highest point of the patio. Dampen the underside of the first slab and lay it down.
Secure the first slab
Gently tap down on the surface with a rubber mallet to bed the slab. If you don’t want to tap directly onto the slab, use a wood block to protect the stone.
Lay the remaining slabs
Once you’ve positioned the key slab, laying the rest is straightforward. You can either work row by row or follow a sequence of your choice. Remember to leave joint gaps between the slabs, using spacers to maintain consistency. You can use wood offcuts to cut your spacers to size.
Remember to check the levels
Use a spirit level to check your levels regularly. The stones should all lie flat to bed into the mortar properly, but the fall must be accurate. You’re aiming for a flat surface that gradually and evenly slopes downwards.
Leave to dry
Slablayer needs at least 48 hours to dry. Cover the patio with plastic sheeting if rain is forecast.
How to lay a patio with mortar
This guide shows how to lay a patio for beginners using the easy-to-use Slablayer. If you have more advanced DIY skills, you can mix your own mortar to secure the slabs.
How to make the mortar mix
Basic patio mortar is four parts sand, one part cement. So for every bucket of cement, you need four buckets of sand. As mortar dries in just a few hours, mix in batches to avoid rushing.
Once you’ve measured the amount of sand and cement needed, it’s time to combine them in a cement mixer. The mortar should be able to hold its shape but be easily mouldable. Here’s how you should create the mix:
Start with some water; around half a bucket
Add half the sand
Mix in all your cement
Add the remaining sand
Add more water if needed
If you don’t have a cement mixer, you can create your mortar using a tray, combining all three elements. In this case, start with less water, adding more gradually as needed.
How to lay the mortar mix
Lay the mortar for one slab at a time, applying 60mm onto the base layer. Prepare the patio slab by spraying some water to ensure it adheres to the mortar.
Then follow the steps above to secure the slab; you can apply more mortar if you spot any gaps. Repeat the process for all other slabs.
How to point a patio: step by step
Pointing is the method of sealing the joints around paving slabs, which helps secure the patio and reduce the risk of movement. This also ensures a tidy and level finish. Here’s the pointing method for small, medium and large joints:
Small joints. For joints less than 5mm wide, use a soft bristle brush to sweep kiln-dried sand into the joints. Then sweep any excess off the finished patio
Medium joints. A dry mortar mix is best for joints 5-10mm wide; use one part sand to one part cement. The addition of cement results in a firmer mixture that will set as it absorbs moisture from the ground. Gradually fill the joints as before and sweep any cement off the slabs to prevent staining. Compress the mixture in the joints and keep adding until the joints are full
Large joints: A wet mortar mix is most suitable for joints more than 10mm wide. Mix four parts sand and one part cement in a bucket and add enough water to make the mixture smooth and damp. Work the mortar into the joints using a trowel, compressing and smoothing, then carefully brush off any excess mixture
You should wait for at least 24 hours before using your new patio, no matter the joint size.
Aftercare
Patios are hard wearing and easy to maintain. Regular brushing and washing will stop algae buildup and keep your outside space looking in top condition. The joints are crucial to your patio’s stability, so look after them by filling in gaps that appear over time and removing any breakthrough weeds.
