Porcelain paving is a popular choice for patios, pathways and other outdoor spaces, but achieving a durable, well-finished surface depends on getting the installation right. Unlike some other types of paving, porcelain has very low water absorption, so the preparation, bedding and bonding process need particular attention.
If you're learning how to lay porcelain slabs, this guide takes you through the process from planning and preparing the ground to laying, jointing and finishing your new patio.
What You Need to Lay Porcelain Slabs
Before you start, gather all the materials and tools you will need. Having everything ready can help you work efficiently once the mortar and other installation products have been prepared.
Materials
You may need:
- Porcelain paving slabs
- Suitable sub-base material, such as MOT Type 1
- Cement
- Sharp sand
- Suitable porcelain paving primer
- Exterior jointing compound or grout suitable for porcelain
- Edge restraints, where required
- Water
- Appropriate cleaning materials
The exact materials and quantities will depend on the paving system, size of the area and ground conditions.
Tools
Useful tools and equipment include:
- Tape measure
- String line and pegs
- Spirit level
- Shovel
- Rake
- Plate compactor
- Trowel
- Mixing equipment
- Rubber mallet or rubber maul
- Straight edge
- Soft or stiff brush, depending on the jointing system
- Suitable diamond cutting equipment
- Appropriate personal protective equipment (PPE)
Step 1: Measure and Plan the Patio
Start by measuring the area you intend to pave. Calculate how many slabs you will need, taking the dimensions of the slabs and the planned joint width into account.
It is worth ordering some additional paving to allow for cuts, breakages and future repairs. Before installation, inspect the slabs and check that you have the correct quantity, colour and format.
You should also think about the final layout before beginning. A dry layout can help you determine where individual slabs will sit and where cuts may be required.
When choosing your materials, consider the colour, size, finish and intended use of the porcelain paving to make sure it is appropriate for your project.
Step 2: Mark Out the Area and Establish the Fall
Mark the perimeter of the patio using pegs and string lines. Check the measurements carefully before beginning excavation.
You also need to establish a suitable fall so rainwater can drain away from the patio rather than collecting on the finished surface.
The exact gradient required will depend on the project and surrounding drainage arrangements. Pay particular attention where the patio meets a house or another building, and make sure the finished level is appropriately planned in relation to existing damp-proof courses and drainage.
Step 3: Excavate the Area
Remove grass, plants, roots, topsoil and any other unsuitable material from the marked-out area.
The depth you need to excavate depends on several factors, including:
- The thickness of your porcelain slabs
- The required mortar bed
- The depth of the sub-base
- Existing ground conditions
- The intended use of the paved area
Rather than using one excavation depth for every project, work backwards from your desired finished level and allow for the complete construction build-up.
For larger or more heavily loaded areas, the required pavement construction may differ from that used for a typical domestic patio.
Step 4: Prepare and Compact the Sub-Base
A properly prepared sub-base provides a stable foundation for the paving above it.
Use an appropriate sub-base material and install it in manageable layers, compacting each layer thoroughly. The finished sub-base should be firm and even while retaining the fall established during the planning stage.
Don't rush this part of the process. Inadequate ground preparation can contribute to movement, settlement and uneven paving later.
Step 5: Prepare the Mortar Bed
Porcelain paving is generally installed on a full mortar bed, rather than being supported by isolated spots of mortar.
The exact mortar mix and bedding depth should be based on the installation instructions for your chosen paving system. Where cement is required, Everything Landscaping's cement for paving installations is listed as suitable for paving installations, mortar and other landscaping applications.
Prepare the mortar progressively rather than spreading a large area that could begin to dry before you have laid the slabs.
The mortar should provide continuous support beneath each slab. Avoid relying on a few isolated points of contact, as this can leave unsupported areas beneath the paving.
Step 6: Prime the Underside of Each Porcelain Slab
Priming is an important part of installing porcelain paving.
Because porcelain has very low water absorption, a suitable primer helps establish adhesion between the underside of the slab and the bedding mortar.
Apply the primer according to the manufacturer's instructions. The Nexus ProJoint Porcelain Primer is specifically formulated as a priming slurry for porcelain paving and is designed to promote adhesion between porcelain and a sand-and-cement bedding system.
Work methodically so that the primer remains suitable for laying when each slab is positioned. Follow the product instructions for application, mixing and drying or working times.
Step 7: Lay the Porcelain Slabs
Place the primed slab carefully onto the fresh mortar bed.
Gently bed the slab using a suitable rubber mallet or rubber maul, taking care not to damage the paving. Check that the slab is properly supported across its surface and does not rock when pressure is applied.
As you work, check:
- The level of each slab
- The fall for drainage
- Alignment with surrounding slabs
- Joint width
- The overall finished height
- Support beneath the slab
It is much easier to correct small alignment issues while the mortar is still workable than after it has begun to set.
Step 8: Maintain Consistent Joints
Keep the gaps between your slabs consistent throughout the patio.
The appropriate joint width depends on the paving and jointing system being used, so check the manufacturer's recommendations rather than choosing a width based purely on appearance.
Consistent joints improve the finished appearance and provide sufficient space for the specified jointing material.
Use suitable spacers if they are recommended for your particular paving system.
Step 9: Check Levels and Drainage
Before the mortar sets, take time to check the finished position of the slabs.
Use a spirit level and straight edge to check that:
- Adjacent slabs are correctly aligned
- There are no unwanted high or low points
- The intended fall has been maintained
- The slabs are properly supported
- Individual slabs do not rock
The patio should have sufficient fall to allow water to drain away. Avoid creating areas where water can collect.
Step 10: Clean the Paving During Installation
Remove mortar, primer and other installation residue from the visible surface as you work.
This is particularly important with jointing products and primers because residue that is allowed to cure on the surface can become much harder to remove.
Use the cleaning method specified by the manufacturer of the relevant product. Don't assume that the same cleaning process is appropriate for every primer, grout or jointing compound.
Step 11: Fill the Joints
Once the paving is ready for jointing, use an exterior jointing product that is specifically suitable for porcelain paving.
The application method will depend on the product. Some jointing systems have particular requirements for wetting the paving, preparing the joints and cleaning the surface afterwards.
When using a jointing compound suitable for porcelain paving, follow the manufacturer's instructions carefully and make sure the joints are completely filled.
Avoid leaving excess jointing material on the face of the slabs, and clean the surface according to the product instructions before the material cures.
Step 12: Allow the Patio to Cure
Your newly laid patio needs time to cure before it is subjected to normal use.
The required curing period will depend on the mortar, primer, jointing product and weather conditions. Always follow the instructions supplied with the products you have used.
Protect the newly installed area from unnecessary foot traffic during the initial curing period.
Don't assume that the patio is ready for normal use simply because the surface feels firm.
Can You Lay Porcelain Slabs Directly on Soil?
No. Porcelain slabs should not simply be placed directly onto soil.
A suitable foundation needs to be prepared beneath the paving. For a typical patio installation, this involves excavating the area, preparing and compacting an appropriate sub-base and then installing the slabs using the specified bedding system.
Skipping or inadequately preparing the foundation can increase the risk of movement, settlement and uneven paving.
Can You Lay Porcelain Paving on Sand?
For a conventional rigid porcelain patio installation, you should not simply place porcelain slabs onto a loose sand bed.
The appropriate bedding system depends on the paving manufacturer's instructions, but porcelain paving is commonly installed using a full mortar bed with a suitable primer to create the required bond.
The Nexus ProJoint Porcelain Primer, for example, is specifically designed to promote adhesion and allow porcelain slabs or setts to be laid on a sand-and-cement bedding system.
Always follow the installation method specified for your particular paving.
How Long Does Porcelain Paving Take to Cure?
There is no single curing time that applies to every porcelain paving installation.
The time required depends on the mortar, primer, jointing system and weather conditions. Product manufacturers may specify different periods before foot traffic or normal use is permitted.
For that reason, follow the curing instructions supplied with the products used rather than relying on a general timeframe.
Common Mistakes to Avoid When Laying Porcelain Slabs
Getting the preparation right is just as important as laying the slabs themselves. Avoid these common mistakes.
Skipping the Sub-Base
A poorly prepared or inadequately compacted sub-base can contribute to movement and settlement.
Spot-Bedding the Slabs
Using isolated spots of mortar can leave parts of the slab unsupported. A full mortar bed is generally recommended for porcelain paving installations.
Forgetting to Prime the Slabs
Porcelain's low water absorption means the appropriate primer is an important part of establishing a suitable bond with the bedding system.
Ignoring Drainage
A patio needs an appropriate fall so rainwater can drain away rather than remaining on the surface.
Using an Unsuitable Jointing Product
Not every exterior jointing product is suitable for porcelain. Check that the product is compatible with your paving and follow the manufacturer's application instructions.
Leaving Installation Residue on the Surface
Mortar, primer and jointing residue can become difficult to remove once cured. Clean the paving during the installation process according to the relevant product instructions.
Rushing the Curing Process
Give the mortar and jointing system sufficient time to cure before allowing normal use of the patio.
What Is the Best Way to Lay Porcelain Paving?
The best approach is to treat the installation as a complete system rather than simply placing slabs onto a prepared surface.
In summary, the process is:
- Plan and measure the area.
- Mark out the patio and establish the fall.
- Excavate to the required depth.
- Prepare and compact the sub-base.
- Prepare the specified mortar bed.
- Prime the underside of each porcelain slab.
- Lay and bed the slabs carefully.
- Maintain consistent joints.
- Check levels and drainage.
- Clean installation residue from the surface.
- Apply a suitable jointing product.
- Allow the patio to cure before use.
The precise mortar mix, bedding depth, primer, joint width and curing period should always be confirmed against the instructions for your chosen paving and installation products.
Choosing Porcelain Paving for Your Patio
Once you know how to install porcelain paving, you can start considering the design and materials for your project.
Think about the size and shape of your patio, the overall style of your garden and how the paving will work alongside other landscaping elements. Colour, surface finish and slab format can all influence the final appearance.
It's also worth considering how the patio will connect with other features, such as garden paths, lawns, planting areas, steps or drainage.
Everything Landscaping's porcelain paving range includes a variety of styles and formats, giving you options to consider when planning your outdoor space. The site also stocks installation products such as the Nexus ProJoint Porcelain Primer alongside its paving range.
Final Thoughts
Knowing how to lay porcelain slabs is only part of creating a successful patio. Careful preparation, a suitable sub-base, the correct bedding system, proper priming and accurate jointing all play an important role in the finished installation.
Take your time with the groundwork and check the manufacturer's instructions at each stage. If you're unsure about the required foundation, drainage or installation method for your project, consider getting advice from an experienced paving professional before you begin.
Frequently Asked Questions
Can you lay porcelain slabs directly onto soil?
No. Porcelain slabs should not be laid directly onto soil. The ground needs to be properly excavated and prepared with a suitable, well-compacted sub-base before the slabs are installed on the recommended bedding system.
Can you lay porcelain paving on sand?
Porcelain paving should not normally be laid directly onto a loose sand bed for a conventional patio installation. A suitable full mortar bed and porcelain-compatible primer are generally required, although you should always follow the installation instructions for your specific paving system.
Do porcelain slabs need a primer?
Yes, a suitable primer is generally recommended when laying porcelain paving. As porcelain has very low water absorption, priming the underside of the slab helps create an appropriate bond between the paving and bedding mortar.
What is the best mortar for porcelain paving?
A suitable sand-and-cement mortar bedding system is commonly used for porcelain paving, but the exact mix and bedding requirements can vary between products. Always follow the manufacturer's installation instructions and use a compatible porcelain paving primer.
How long should you leave a porcelain patio before walking on it?
The required curing time depends on the mortar, primer, jointing product and weather conditions. Follow the manufacturers' instructions for the products used and avoid normal foot traffic until the installation has sufficiently cured.