Kandla Grey sandstone is one of the UK's most popular choices for patios and paths, thanks to its durability and calm, timeless colour. Getting the installation right is what keeps this Indian sandstone paving looking sharp for years, not months. Many of the problems people encounter later, like cracked slabs, uneven surfaces, water collecting near the house, can usually be traced back to shortcuts taken at the very beginning, before a single slab is even laid.
The good news is that none of this requires specialist skill. It comes down to following the right order, allowing each stage enough time, and not rushing the less exciting parts, such as compacting the base or letting the mortar cure properly. Whether you're laying a small patio or a full driveway, the same principles apply throughout.
Here's a complete step by step guide to installing Kandla Grey paving, covering everything from ground preparation to sealing, along with the finer details that separate a patio built to last for decades from one that needs redoing within a couple of years.
What Is Kandla Grey Sandstone?
It's a natural stone quarried in India, with a cool grey tone carrying hints of blue and silver and subtle veining that varies slightly from slab to slab. This stone holds its colour well outdoors and withstands UK weather better than many alternatives, which is a large part of why it has become such a popular choice for driveways and garden patios. Worth browsing the full Kandla Grey Indian sandstone collection first, since photos rarely capture the tonal shifts between slabs.
There are a few finish options worth understanding before buying these natural sandstone slabs. Riven slabs have a textured, natural surface with strong grip. Smooth sawn slabs give a cleaner, contemporary appearance. Tumbled slabs have softened edges, suited to a cottage style garden. The laying method stays largely the same across all finishes, so choose based on appearance rather than difficulty.
Tools and Materials You'll Need
- Kandla Grey sandstone slabs in your chosen size and finish
- MOT Type 1 hardcore for the sub base
- Sharp sand and cement, or a ready mixed bedding mortar
- SBR slurry primer (optional but recommended)
- Rubber mallet and spirit level
- String lines, stakes, and a tape measure
- Plate compactor or hand tamper
- Pointing or flexible jointing compound
- A stone sealer, for later
For quantities, the Kandla Grey riven sandstone 600x900 paving slabs page lists coverage per pack. Order five to ten percent extra to allow for cuts and breakages.
How to Lay Kandla Grey Sandstone Step by Step
Once your tools and stone are ready, the installation comes down to six steps completed in order. Rushing any one tends to create problems later, so take your time here.
Step 1: Mark Out and Excavate the Area
Mark the boundaries using string lines and stakes, keeping every corner precisely square. Dig down about 150mm for a patio, or closer to 200mm for a driveway bearing vehicle weight. Clear away roots, old soil, or buried debris, since organic material left underneath will eventually decompose and cause the ground to settle unevenly.
Build in a gentle slope, roughly 1 in 80, to direct water away from the house. Without it, rainwater collects against walls or doorframes instead of draining off.
Step 2: Build the Sub Base
Lay the hardcore in layers of about 50mm, compacting each layer thoroughly before adding the next. Skipping proper compaction here is one of the leading causes of uneven or sinking paving within the first year. Once firm and level, you're ready for the mortar.
Step 3: Mix and Spread the Mortar
Mix four parts sharp sand to one part cement, adding water gradually until it holds together firmly without being too wet. Spread a full mortar bed across the area rather than placing mortar only under the corners, as a full bed supports is what most professional landscapers recommend for lasting stability. After compaction, aim for a bed depth of around 30 to 40mm. Work on one section at a time, mortar dries faster than expected.
Many installers apply an SBR slurry primer to the underside of each slab before bedding it down. It helps the stone bond securely to the mortar and reduces the risk of hollow spots or loose slabs later, something manufacturer guidance often recommends for natural stone paving. For layout inspiration beyond a plain grid pattern, see our guide on how to incorporate Kandla Grey sandstone in your garden design.
Step 4: Lay the Slabs
Place each slab onto the mortar and tap it down gently with a rubber mallet, checking level in both directions as you go. Maintain a consistent joint gap, typically 10 to 15mm, using spacers if this is your first attempt. Begin at a straight edge, such as a wall or doorway, so the pattern remains square throughout the area.
Natural stone is rarely uniform in thickness, so keep extra mortar nearby to support thinner slabs and maintain a flat, even surface. If you're weighing up whether this stone suits your home, our piece on why homeowners choose Kandla Grey sandstone paving slabs covers the practical reasons behind its popularity.
Step 5: Point the Joints
Let the mortar cure for at least 24 hours before pointing. Fill the joints firmly using a pointing or flexible jointing compound, removing excess before it hardens on the surface, it's far harder to remove once set. In line with general guidance for laying natural stone paving, such as the principles outlined in BS 7533, a neatly filled joint also helps prevent water from seeping beneath the stone.
Step 6: Clean, Seal, and Allow It to Cure
Once pointing has fully cured, usually within a week, wash the area thoroughly to clear dust and residue. Sealing is optional for Kandla paving slabs, but adds a protective layer against staining and algae, and simplifies ongoing maintenance.
Timing matters too. Avoid walking on the paving for 24 to 48 hours after laying, hold off on furniture for around 4 to 7 days, and allow about 2 to 3 weeks before driving a vehicle over it, even if the base has been properly built.
Mistakes That Undermine the Finished Result
- Applying mortar only at the corners instead of a full bed
- Skipping proper compaction of the sub base
- Failing to build in a slope, causing water to pool
- Leaving no gap between slabs
- Using the paving before the mortar and pointing have cured
Kandla Grey vs Raj Green Sandstone
A common question once people start browsing is how Kandla Grey compares to Raj Green, another widely used Indian sandstone.
|
Feature |
Kandla Grey |
Raj Green |
|
Colour |
Cool tones, silver to blue grey |
Warmer tones, buff, green, and gold undertones |
|
Best suited to |
Modern, minimal gardens |
Traditional or cottage style settings |
|
Durability |
Dense, frost resistant, long lifespan when installed correctly |
Dense, frost resistant, comparable lifespan when installed correctly |
|
Maintenance |
Same sealing and cleaning approach as most Indian sandstone |
Same sealing and cleaning approach as most Indian sandstone |
The decision comes down to which tone complements your garden and home exterior, rather than one stone being technically superior.
Summary
If there's one principle to take from this guide, it's that the final result depends almost entirely on what happens before the first slab is laid. A properly excavated and compacted sub base prevents the ground from sinking or shifting later, and a gentle slope ensures rainwater drains away from the house rather than gathering against it.
Beyond that, consistency makes the difference. Use a full mortar bed rather than placing mortar only at the corners, keep joint gaps even across the entire area, and resist rushing the curing time at any stage. A day for the bedding mortar, a week for the pointing, and considerably longer before furniture or vehicles, these waiting periods may feel slow, but they protect the finished result.
Get these fundamentals right, and this Kandla Grey sandstone paving will retain its appearance and structural integrity for many years, requiring little beyond an occasional clean and, if desired, a seal applied periodically.
Ready to get started? Order Kandla Grey riven sandstone slabs here.
Frequently Asked Questions
How long does laying Kandla Grey sandstone take?
For around 20 square metres, expect two to three days, covering sub base preparation, laying, and pointing.
Do you need to seal it?
Not strictly, but it's beneficial. Sealing protects against staining and algae and simplifies maintenance, though the stone performs well without it too.
How wide should the gaps between slabs be?
Most installers use 10 to 15mm, filled with jointing compound once the mortar has cured.
Can it be used for driveways?
Yes, provided the sub base is built to a greater depth, around 200mm of compacted hardcore rather than the 150mm used for patios.
Why does it sometimes appear patchy after laying?
Usually due to natural variation between slabs, or leftover cement residue on the surface, which typically clears with a thorough wash.
