Quick answer
For a traditional mortar-bedded pedestrian patio, laying porcelain paving starts with preparation: a compacted sub-base, the right bedding layer, a slurry primer on the slab backs and full, well-compacted joints. Porcelain has low water absorption, so it bonds differently to natural stone. Follow the manufacturer's instructions for every product and agree the full build-up with your installer before ordering.
The build-up from the ground up
A typical porcelain patio is built in layers. Excavate to the depth your installer calculates for the soil and expected load, then place and compact a sub-base of crushed aggregate. The bedding layer above it is commonly a mortar mix laid to the agreed falls so water drains away from buildings. Each slab is buttered on its back with slurry primer before being laid and levelled. Joints are filled last with a suitable jointing material.
This describes a traditional mortar-bedded installation. Other systems need their own product-specific design; a slab suitable for one system is not automatically suitable for another. An unsuitable build-up can cause rocking, cracking or lifted slabs. Porcelain in particular needs the primer step because its low porosity limits how ordinary mortar grips the back of the slab.
Priming is the step people skip
Slurry primer is brushed onto the clean back of each slab just before laying. It creates the bond between the dense porcelain body and the bedding mortar. Skipping it, or letting the primer skin over before laying, is a common cause of slabs that sound hollow or come loose. Mix only what can be used within the product's working time and follow the manufacturer's instructions for coverage and conditions.
Jointing and pointing
Jointing fills the spaces between slabs, but it does not replace the bedding support or drainage design. Some compounds are permeable. Follow the selected compound’s requirements for joint width, depth, bedding permeability and preparation; do not assume any jointing material makes a patio waterproof or weed-proof. Joint-It Simple jointing compound is one option; your installer may recommend another system for the site. Whatever is used, joints should be filled fully and compacted, with tooling finished as the product instructions describe.
Falls, drainage and cuts
Plan where the water goes before the first slab is laid. Agree the falls and drainage with your installer for the selected paving and the site. Check drains, manholes and door thresholds so the finished level works everywhere. Calculate the cutting allowance from the agreed layout; an L-shaped or heavily cut patio can need a different allowance from a plain rectangle.
Quantity and product planning
Use the paving quantity calculator with the measured area and installer-agreed allowance, then check the selected product option's published coverage. Keep the paving, primer, jointing and any edging together on the project list so the whole system is priced before anything is ordered.
What to confirm before ordering
- The exact paving product, format and pack options, plus a sample of that product.
- The sub-base depth and bedding mix for your soil and expected load.
- The primer product, coverage and working time, and who applies it.
- The jointing product, joint width and tooling method.
- Falls, drainage points and finished levels against doors and drains.
- The cutting allowance for the actual layout, not a flat percentage.
- Delivery access and the unloading point for pallets.
Read the delivery and returns information and Before you order checklist, and browse the laying and care collection for the installation products mentioned here.
Common questions
Can porcelain paving be laid on sand?
Porcelain is normally laid on a mortar bed over a compacted sub-base, with slurry primer on the slab backs. Do not substitute a sand-only method for a specified bonded installation. An alternative installation system requires confirmation that the exact slabs and build-up are suitable. Confirm the build-up with your installer.
How long before I can walk on a new porcelain patio?
It depends on the bedding and jointing products used. Mortar beds and jointing compounds need curing time that varies with weather and product, so follow the manufacturer's instructions before foot traffic and longer before heavy loads.
Do I need to seal porcelain paving after laying?
Porcelain is dense and does not need sealing in the way natural stone does. Cleaning and grout haze removal are separate questions; use products suited to porcelain and follow their instructions.
Sources and scope
This guide covers planning for a traditional mortar-bedded pedestrian porcelain patio. Manufacturer guidance from Marshalls describes full mortar-bed support and priming for that method. It is background reading, not a substitute for the instructions for the actual slabs and installation products ordered. Confirm the site design with your installer.