Sunken pavers, wobbly slabs and weeds pushing up through the joints almost always come back to one thing: the base. Spend your effort below the surface and a paved path or patio will stay flat for years.
The layers
A typical garden path or patio is built in three layers:
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Sub-base: compacted Daltons GAP20 or Daltons PAP7 (crusher dust), usually 75–100mm for foot traffic. This carries the load.
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Bedding layer: a thin, level layer of Daltons No1 Washed Sand, about 5–10mm, screeded smooth so each paver sits evenly and doesn't rock or crack.
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Pavers, with fine sand brushed into the joints.
Step by step
1. Plan levels and drainage
Mark out the area with string lines and pegs. Give the finished surface a gentle fall, about 1:100 (10mm per metre), away from the house so rain runs off rather than pooling. Patios should always finish below floor level.
2. Excavate
Dig out to the depth of your base + bedding layer + paver thickness. Remove all topsoil, roots and soft spots; organic material underneath will rot and sink.
3. Lay and compact the sub-base
Spread GAP20 or PAP7 in layers no thicker than 75–100mm and compact each one with a vibrating plate compactor. Slightly damp material compacts best. Check your levels and falls as you go — it's much easier to fix them now than later.
4. Install edge restraints
Pavers need something to stop them spreading: a concrete haunch, a mowing strip or fixed edging. Set it before you lay the pavers. Daltons Builders Mix with cement added makes a strong concrete edge.
5. Screed the bedding sand
Spread No1 Washed Sand over the compacted base and screed it flat with a straight board running on guide rails. Don't walk on it once it's screeded.
6. Lay the pavers
Work from a fixed edge or corner, placing each paver straight down rather than sliding it. Keep joints even and check alignment with your string line every few rows. Cut pavers to fit edges last.
7. Compact and joint
Brush dry, fine sand into the joints, then run the plate compactor over the surface (with a rubber mat fitted to protect the pavers). Top up the joint sand and repeat until the joints are full. Full joints lock the pavers together and leave less room for weeds.
Other uses for crusher dust
PAP7 is a 0–7mm crushed aggregate that spreads easily and compacts smooth and firm. As well as paving, it's ideal as a level base for:
- water tanks
- garden sheds and playhouses on pavers
- drainage pipes (bedding and surround)
- cobbles and stepping stones
How much do I need?
Base: area × base depth, plus 20–25% for compaction. Bedding sand: area × 0.01 (for 10mm) is plenty, with a little extra for jointing. A 3m × 4m patio with a 100mm base needs about 12 × 0.1 = 1.2 m³ plus 25%, so order 1.5 m³ of base and ½ m³ of sand. More on calculating volumes in How Much Do I Need?
Quick answers
GAP20 or crusher dust for the base? Both work for foot-traffic paving. GAP20 is the stronger choice for larger or heavier-use areas; PAP7 is finer, easier to screed and ideal for smaller projects and tank pads.
Can I lay pavers straight onto soil? Not if you want them to stay level. Soil moves as it wets and dries, and pavers will sink and rock.
How do I stop weeds in paver joints? Keep joints full of sand. On existing paving, a pre-emergent such as Barricade helps stop new weeds germinating — see Stop Weeds Before They Start.
Related reading
Note: Product in image may differ from product sold at our yards.
