How we lay cabro, in ten steps
The blocks are the visible part. The base under them is what decides whether the driveway is still flat in ten years. This is the sequence we follow on every job, and it is the sequence to ask any contractor about.
Step 1: Setting out and levels
We peg the area, set finished levels and mark the falls so water runs off — usually 1 in 60 to 1 in 80 away from the house.
Step 2: Excavation to formation
Dig to the depth the base needs: deeper for 80mm duty, and deeper again where black cotton soil is present.
Step 3: Remove black cotton soil
Black cotton swells and shrinks with the seasons. It comes out and is replaced with stable murram fill, compacted in layers.
Step 4: Hardcore base
Hand-packed hardcore, compacted in layers — commonly 150–300mm depending on traffic. This layer carries the load, not the blocks.
Step 5: Murram or quarry-dust blinding
A thin layer to fill the voids in the hardcore, compacted with a plate compactor or roller to a firm, even surface.
Step 6: Sand bedding
30–50mm of coarse sand screeded to level with the falls built in. Not compacted yet — the blocks will bed into it.
Step 7: Laying the blocks
Laid in pattern from a straight edge: herringbone for vehicle areas (strongest interlock), stretcher or basket weave for walkways. Pallets are mixed as we go to blend colour shades.
Step 8: Edge restraint
Kerbs or a concrete haunch along every free edge. Without it the whole field creeps outward and the joints open up.
Step 9: Cuts, joint sand and compaction
Edge blocks are cut with a saw, fine dry sand is swept into the joints, and the surface is vibrated with a plate compactor so the blocks lock together.
Step 10: Final sweep and handover
A last sand sweep to top up the joints, then the area is ready to use the same day — no curing time.
Included in the laying price
- Setting out and levels
- Sand bedding, screeding and laying
- Edge cuts and joint sand
- Plate compaction and final sweep
- Clearing off-cuts and packaging from site
Priced separately, after the site visit
- Excavation and black cotton removal (quoted separately after a site visit)
- Hardcore, murram and base compaction (quoted per m² by depth)
- Kerbs and concrete haunching (quoted per metre)
- Drainage channels and manhole adjustments
Base work varies from almost nothing on firm red soil to the largest line on the quote on black cotton soil. That is why we do not price it blind.
Herringbone for vehicles, stretcher for feet
Herringbone (blocks at 45° or 90° to the driving direction) gives the strongest interlock, because no joint runs continuously in the direction a tyre pushes. Stretcher bond and basket weave are quicker to lay and fine for walkways and patios. On a slope we always use herringbone and a concrete haunch at the bottom edge.
The trade-offs, said plainly
- Cabro only performs as well as its base. Expensive blocks on a cheap, uncompacted base will sink and rut within a year.
- Joint sand needs topping up every few years, and weeds can take hold in joints that are left empty.
- A complex pattern costs more to lay and wastes more blocks in cuts than a simple one.
- On a properly prepared base, cabro lasts 15–25 years or more. We do not promise beyond that.
How long it takes
Once the base is ready, a laying team covers roughly 40–80 m² a day depending on pattern and the number of cuts. A 100 m² home compound is usually laid in two days and usable the same evening. The base work before that — excavation, murram, hardcore, compaction — takes as long again, or longer on black cotton soil.
Ready to have it laid?
Send the area and your town. We book a site visit, dig a test pit, and quote the whole job line by line.