Sandstone slabs are a popular choice for creating durable and attractive patios, pathways, or garden features. Sandstone’s natural beauty and resilience make it an excellent material for outdoor use and they are relatively easy to install for an experienced DIY-er.
Tools and materials needed to lay sandstone slabs
- Sandstone slabs
- Shovel
- Spirit level
- Rubber mallet
- String line
- Tape measure
- Wheelbarrow
- Hardcore (such as crushed stone)
- Sharp sand
- Cement
- Water
- Trowel
- Brush
Step 1: Plan your layout
Start by planning your project. Measure the area where you want to lay the slabs and calculate the quantity needed. Consider the pattern you want, such as random, staggered, or a grid. A well-thought-out plan ensures minimal waste and an aesthetically pleasing result.
Step 2: Prepare the ground
Proper preparation is crucial for a stable and long-lasting surface:
- Clear the area by removing any grass, weeds, or debris.
- Excavate - dig down to a depth of about 150mm (6 inches). This depth accommodates the sub-base and bedding layers while leaving space for the slabs.
- Level the ground using a spirit level to ensure a flat surface. Uneven ground can lead to shifting slabs over time.
Step 3: Lay the sub-base
A sturdy sub-base provides the foundation for your slabs.
Spread hardcore - fill the excavated area with a 50-70mm (2-3 inches) layer of hardcore.
Compact the hardcore using a plate compactor or hand tamper to press the hardcore into a solid, even layer. This step prevents movement and adds stability.
Add sharp sand - spread a 30-50mm (1-2 inches) layer of sharp sand on top of the hardcore. Level it with a straight edge and compact it again.
Step 4: Mix the mortar
Prepare a mortar mix to secure the slabs, with a mix ratio of four parts sharp sand to one part cement. Add water gradually until the mixture achieves a thick, creamy consistency. Avoid making the mix too wet, as this can weaken the bond.
Spread the mortar mix onto the prepared surface, working in sections to prevent it from drying out before the slabs are laid.
Step 5: Lay the sandstone paving slabs
When laying the slabs, always start from a corner and work outwards, laying each slab onto the mortar bed. Once the slabs are in the correct position, use a rubber mallet to tap them into place, ensuring full contact with the mortar.
After laying each slab, use a spirit level to check for evenness. Adjust by adding or removing mortar as needed.
Maintain consistent gaps by using spacers or your tape measure to ensure uniform gaps between slabs. This is especially important if you plan to grout later.
Step 6: Fill the joints
Once all the slabs are laid, they must be given time to sit undisturbed for 24-48 hours to allow the mortar to set, before filling the joints with a grout or jointing compound. Use a trowel or a pointing tool to fill the gaps between the slabs and smooth the surface. Any excess grout should be wiped away with a damp sponge or cloth before it dries.
Step 7: Finishing touches
Once the joints are set, sweep the surface to remove loose material. You may also want to seal the sandstone slabs to protect them from stains and weathering, though this step is optional based on your preference.
How to maintain sandstone slabs
Follow these simple steps to keep your sandstone surface looking its best:
- Regularly sweep away dirt and debris.
- Clean with a mild detergent and water when needed.
- Reapply sealant every few years, if used.
For more advice on how to clean sandstone paving, read How to look after your patio.
Sandstone paving slabs from Witham Timber
Laying sandstone slabs is a rewarding project that enhances the functionality and beauty of your outdoor space. With the right tools, materials, and preparation, you can achieve a professional finish that lasts for years. Whether you’re building a patio or creating a garden path, Witham Timber has all the materials you will need, including all required aggregates. Our sandstone paving forms a small part of the paving we supply, which includes decorative porcelain paving, block paving and functional council paving slabs.
For any further help or advice, call our sales team on 01205 359188 or send an email to sales@withamtimber.co.uk