You have drawn the surface, picked the pattern, and calculated the sub-base. Two questions are still open: how deep does the hole need to be, and what about the curbstones that hold everything in place? Version 1.0.15 fills those gaps.
Excavation depth at a glance
First-time patio builders consistently underestimate how deep they need to dig. The shopping list now shows an “Excavation depth” table with a clear layer breakdown:
- Base layer: 20 cm (pedestrian), 30 cm (drivable) or 50 cm (tank)
- Bedding: always 4 cm of grit
- Brick height: depends on the chosen paver (e.g. 6 or 8 cm)
- Total: the depth you need to excavate
For a typical garden patio with a 6 cm paver and pedestrian loading, that is 30 cm. It sounds modest, but over 12 m² that is 3.6 cubic metres of soil to shift.
Curbstones and cement requirement
Without edge restraint, pavers drift apart over the years. The shopping list now converts the surface perimeter into curbstone quantities:
- Piece count: standard length 1 m, rounded up
- Cement mortar: 40 kg per curbstone (foundation bed + haunching)
- Bags of 25 kg: so you grab the right amount at the store
40 kg per stone is a lot, but a proper concrete foundation (10 cm deep, 20 cm wide) plus haunching on both sides needs exactly that. Use less and you will have wobbly stones after two winters.
Trass cement instead of Portland cement
For curbstone foundations we recommend trass cement (CEM II) over plain Portland cement. The reason is fewer efflorescence stains. Trass binds free calcium hydroxide that otherwise migrates to the surface as a white haze on dark stones.
For a cheaper mix, blend trass cement and Portland cement 1:1 with 4 parts sand. You keep most of the efflorescence protection and pay less. All the details are on the new topic page Trass cement for curbstones.
Share your plan with friends
The Share button in the top-right corner of the planner is easy to miss. One click gives you a link with your complete paving layout: surface, pattern, joint width and colour.
Send it to:
- The neighbour who is helping out on Saturday
- The builders’ merchant so they can prepare the right quantities
- The garden WhatsApp group for feedback before you break ground
The recipient opens the link and sees your plan without installing anything. Try it: open the planner, draw a surface, click “Share” → “Share link”.