How to Lay a Patio: Base, Fall, Slabs and Drainage
Project Overview
A patio needs more than attractive slabs. The base, fall, edging and drainage decide whether it stays flat, avoids puddles and does not send water where it should not go.
Safety Note
Paving work involves heavy lifting, dust, cutting tools and trip hazards. Wear PPE and use dust control when cutting. Do not direct water onto neighbouring land, towards the house, or into drainage systems without checking what is allowed. Large patios, level changes and drainage alterations may need professional advice.
Before You Start
- Measure the area and plan the slab layout before ordering.
- Check the finished height against damp proof courses, door thresholds and air bricks.
- Plan a slight fall away from buildings.
- Choose paving, edging and jointing suitable for outdoor use.
- Work out where surface water will go.
Step-by-Step Method
- Mark the patio area and remove turf or existing surface.
- Excavate to allow for sub-base, bedding and slab depth.
- Compact the sub-base in layers.
- Set string lines for height and fall.
- Lay slabs carefully from a straight reference edge.
- Check level, alignment and joint spacing as you work.
- Fill joints and protect the area while materials cure.
Common Mistakes
Thin bases, poor compaction, no fall, random cuts and ignored drainage create most patio failures.
When to Get Help
Use a professional for large patios, complex drainage, steps, retaining edges, porcelain cutting, or work close to thresholds and damp proof courses.
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