Hammer Stone Grey Porcelain Paving Slab 900x600 20mm

Please note that paving slabs are produced in batches and natural colour variations may occur. We strongly recommend ordering all required slabs in one order to ensure colour consistency. Mixing batches may result in visible shade differences.

Ordering Guide – Outdoor Porcelain Paving

Measuring your area:
Carefully measure the total area to be paved and calculate the required square metre coverage.

We recommend allowing an additional 10% for cuts, wastage and breakages.
For complex layouts, steps, curves or diagonal patterns, consider allowing up to 15% extra.

Pack sizes & coverage:
This product is available in full packs and split pack quantities. Coverage per pack is clearly stated on the product page. When ordering split packs, ensure that the total coverage required is met, including allowance for wastage.

Batch consistency
Porcelain paving is manufactured in production batches, and minor variations in tone and surface texture may occur between batches. To ensure colour and finish consistency, we strongly recommend ordering the full required quantity in one order. Additional orders placed at a later date may come from a different batch.

Joint width & layout considerations:
A minimum joint width of 5mm is recommended for outdoor porcelain paving. Please note that porcelain tiles are subject to manufacturing tolerances. Layouts using oblong tiles with a 50% brick bond can increase the likelihood of lipping. For best results, we recommend a maximum offset of 30% when installing rectangular tiles.

Delivery & access:
Porcelain paving is delivered on pallets via a tail-lift equipped HGV unless otherwise requested.

Please ensure:
Suitable access for large delivery vehicles

A flat, solid offload area, Any restrictions (weight limits, narrow roads, timed access) are advised at the time of ordering

Failed or aborted deliveries may incur additional charges.

Storage on delivery:
Pallets should be stored on a flat, level surface and kept wrapped until installation.
Avoid stacking pallets or storing tiles on uneven ground.

Professional installation:
Outdoor porcelain paving should be installed by a competent professional installer using appropriate materials and methods.

Incorrect installation may affect performance and invalidate product guarantees.

Returns & cancellations:
Please check your order carefully before confirming. Returns may be accepted in line with our returns policy, provided goods are unused and in original packaging. Customers are responsible for arranging and covering the cost of return transport.

20mm Outdoor Porcelain Patio Installation Guide

Sub-base preparation:
Excavate the installation area to the required depth and install a minimum 150mm Type 1 MOT sub-base, compacted in layers to create a stable foundation.

A suitable edge restraint should be installed where required to maintain long-term stability.

Bedding & adhesion method:
All 20mm porcelain tiles must be installed on a full contact mortar bed.
Dot and dab installation is not suitable for outdoor porcelain paving.

A slurry primer must be applied corner to corner on the reverse of every tile to ensure maximum adhesion between the porcelain and the mortar bed. Tiles should be fully primed immediately prior to laying.

Adhesion is achieved through the combination of the slurry primer and the full mortar bed, ensuring complete support across the entire tile.

Mortar bed specification:
Full mortar bed installation only
Minimum mortar bed thickness: 50mm
Mortar should be applied evenly to provide full contact beneath each tile
Tiles must be firmly pressed into place to eliminate voids and ensure full bedding support.

Jointing:
Once the installation has fully cured, joints should be filled using either:
An exterior-rated porcelain grout, or
A specialist porcelain brush-in jointing compound
Minimum recommended joint width: 5mm
Adequate joint spacing is essential to accommodate tolerances and to achieve a consistent, professional finish.

Falls & drainage:
A minimum fall of 1:60 away from buildings must be incorporated into the installation to allow effective surface water drainage and prevent standing water.

Intended use:
This installation guidance applies to patios and pathways only.
Tile flatness, tolerances & layout guidance
Porcelain tiles are inherently not perfectly flat due to the challenges encountered during the firing process, particularly during the shrinkage phase. As a result, ISO manufacturing tolerances apply.
Warpage of up to 0.5% of the tile length is permitted under ISO standards.
For example:
A 1200mm tile may exhibit up to 6mm of warpage and still fall within acceptable tolerance. In practice, we typically expect warpage to be in the region of 2–4mm, rather than at the maximum allowable limit. This measurement applies to each side of the tile, when a spirit level is positioned centrally across the tile, as illustrated in standard warpage measurement guides.

Due to these inherent tolerances:
Achieving absolute flatness in porcelain tiles is not possible
Slight curvature or bowing is normal and may vary between production batches. When installing oblong porcelain tiles, laying them in a 50% brick bond pattern can make achieving a flush surface more difficult.
We therefore recommend a maximum offset of 30% when installing rectangular porcelain tiles to minimise lipping and achieve the best visual result.

Installer responsibility:
Installation should be carried out by a competent professional installer.
The installer must assess site conditions, base suitability, drainage requirements and installation materials to ensure compliance with best practice and long-term performance.