Patio slabs and fence work

A well-executed project ensures proper drainage, structural stability, and a seamless transition between your home and outdoor space. This guide covers everything from material choices to the latest UK regulations to help you plan your garden overhaul with confidence.

What Does the Work Involve?

• Site Clearance: Removal and legal disposal of old slabs, broken fence panels, and organic waste.
• Excavation: Digging out the area to a depth of roughly 150mm to 200mm to accommodate the sub-base.
• Sub-base Preparation: Laying and compacting MOT Type 1 crushed stone to create a solid, level foundation.
• Fencing Installation: Setting fence posts in deep concrete footings (usually 600mm deep) and fitting panels or closeboard.
• Laying Slabs: Bedding paving onto a full mortar bed with correct falls to ensure water runs away from the house.
• Jointing and Finishing: Applying resin-based pointing or traditional mortar and installing gravel boards to protect fence panels from ground rot.

Typical Costs

Prices for patio and fencing work vary significantly based on your choice of materials—porcelain and natural stone carry a premium over basic concrete. The following estimates include labour and materials for 2025/26, inclusive of VAT.

Factors that will push costs toward the "High" end include restricted access (e.g., carrying materials through a terraced house), the need for a skip permit on a public road, and complex patterns or curved edges in the paving.

How Long Does It Take?

• Minor Repairs: Replacing 2-3 fence panels or a few loose slabs typically takes 4 to 6 hours.
• Standard Fencing Run (5-8 panels): Usually completed in 1 to 2 days, depending on ground hardness.
• Medium Patio (20-30m²): Expect 3 to 5 days to allow for excavation, base compaction, and curing time.
• Full Garden Overhaul: A combined project involving a new patio and perimeter fencing usually takes 7 to 10 working days.

DIY or Professional?

While a confident DIYer can replace a fence panel, a full patio installation is a heavy, technical task. Incorrectly laid patios can lead to "puddling" against your home's walls, potentially causing damp issues or breaching your Damp Proof Course (DPC).

Professional landscapers have the heavy-duty compaction plates and diamond-blade cutters required to ensure a finish that won't sink or crack within two seasons.

Fencing also requires significant physical strength and precision; if posts are not set deep enough in "post-mix" concrete, they will likely lean or fail during the first winter gale. For any electrical work, such as integrated patio lighting, you must hire a Part P registered electrician.

Choosing the Right Tradesperson

• Check Portfolios: Look for photos of "work in progress" to see the depth of the sub-base, not just the finished surface.
• Verify Insurance: Ensure they hold Public Liability Insurance (minimum £1 million-£2 million).
• Waste Licence: Ask to see their Upper Tier Waste Carrier Licence to ensure your old garden waste isn't fly-tipped.

Questions to ask:

• "Will the slabs be laid on a full mortar bed or 'spots'?" (Avoid spots/dots as they lead to instability).
• "How do you plan to handle surface water drainage?"
• "Are gravel boards included in the fencing quote to prevent the wood from rotting?"
• "Do you provide a written guarantee for your workmanship?"

UK Regulations

• Planning Permission: Generally not needed for fences under 2 metres high (or 1 metre if adjacent to a highway).
• Permeable Surfaces: If the patio exceeds 5m², you must use permeable paving or direct run-off to a lawn/flowerbed to comply with SuDS (Sustainable Drainage Systems) rules.
• The Party Wall Act: If you are replacing a fence on a boundary shared with a neighbour, you must inform them and agree on the boundary line beforehand.
• Damp Proof Course: Patios must be finished at least 150mm (two brick courses) below your home's DPC.

Common Problems

• Efflorescence: White salty stains appearing on new slabs. This is natural but can be minimised by using quality materials and sealants.
• Sinking Slabs: Usually caused by a sub-base that is too thin or poorly compacted.
• Wind Damage: Fences failing because posts were "stabbed" into the ground rather than being set in 600mm of concrete.
• Boundary Disputes: Replacing a fence in the wrong position. Always confirm the boundary using your Title Deeds if unsure.

Frequently Asked Questions

Do I need to seal my new patio slabs?

It depends on the material. Natural stone like Sandstone benefits from sealing to prevent staining, while Porcelain is non-porous and generally doesn't require it. Wait at least 3 months for any efflorescence to clear before sealing.

Can I lay a new patio over my old one?

This is rarely recommended. It usually raises the height too close to the house DPC and doesn't allow you to check the stability of the ground underneath, leading to cracks later.

Which is better: wooden or concrete fence posts?

Concrete posts are more expensive and harder to install but will last decades without rotting. Wooden posts look more natural but usually require replacement every 10–15 years, even if pressure-treated.

What is the best time of year for this work?

Spring and autumn are ideal. Extreme heat can cause mortar to dry too quickly and crack, while frost and heavy rain can ruin the sub-base preparation and prevent concrete from setting correctly.

How do I know who owns the fence between me and my neighbour?

Check your house deeds for a 'T' mark on the boundary line. The 'T' usually points into the property of the person responsible for the fence. If there is an 'H' (two Ts joined), it is a shared responsibility.