How to lay Porcelain Paving Slabs

Porcelain paving slabs can be installed onto either a pre-prepared concrete base or a compacted MOT Type 1 sub-base, depending on the project requirements and ground conditions.

Laying Porcelain Paving on MOT Type 1

The most common installation method for porcelain paving is using a compacted MOT Type 1 crushed stone base. This should be installed to a compacted depth of approximately 100–150mm and compacted in layers using a whacker plate to create a stable foundation.

Once the sub-base is prepared, the porcelain slabs should be laid onto a full mortar bed of approximately 30–40mm thickness. A typical mortar mix is 4:1 sharp sand to cement.

Before laying, all 20mm porcelain paving slabs should be primed using a porcelain slurry primer to ensure proper adhesion. We recommend using UltraScape Pro-Prime Slurry Primer, making sure the entire back of the slab is fully coated before placing onto the mortar bed.

Falls and Drainage

Correct drainage is essential when installing outdoor porcelain paving. A minimum fall of 1:80 away from the property is recommended, although many installers prefer a 1:60 gradient for improved water runoff.

The gradient should remain consistent across the entire patio area, ensuring that drainage channels and gullies sit lower than the finished paving level to prevent standing water.

Laying Porcelain Paving on a Concrete Base

Porcelain paving can also be installed onto a concrete base instead of hardcore. In this case, a minimum 100mm reinforced concrete slab should be laid on well-compacted ground.

As with any installation, the concrete base must include the correct drainage fall of at least 1:80 away from buildings.

The porcelain slabs can then be fixed using either a flexible exterior tile adhesive or a full mortar bed. A slurry primer should still be applied to the back of every slab to guarantee a strong bond.