How a Patio Should Be Laid and What Good Work Looks Like

A patio that lasts sits on a compacted crushed-stone sub-base, is bedded properly on a full layer of mortar, has a slight fall so water runs away from the house, and sits well below the damp-proof course. The groundwork you cannot see is where corners get cut, so checking the preparation is the best way to ensure the paving survives. This guide explains what correct patio work looks like so you know what you should see on site.

Before digging starts, it helps to understand the different trades. Hard landscaping is the built part of a garden, which includes patios, paths, walls, steps, decking, fencing and drainage. Soft landscaping is the living part, covering soil, turf, planting and trees. A garden designer produces the plan, a landscaper or landscape contractor builds it, and a gardener maintains it. For a patio project, you need a landscaper.

The table below sets out the main stages of building a patio and what you should expect to see as the work happens.

These stages reflect typical practice for a reliable patio build. The visible paving is only the final layer of a much deeper structure. A landscaper who rushes the hidden groundwork will leave you with a patio that sinks, cracks or holds water.

Marking out and digging out

Digging risks hitting hidden pipes and cables buried under your lawn. A professional checks for them using a Cable Avoidance Tool before putting a spade in the ground. The excavation depth depends on the thickness of the layers going into it. Typical excavation depths range roughly from 150 to 200mm. A typical example is an excavation of 175mm total depth. This allows space for the foundation, the mortar bed and the slabs themselves.

Access plays a large part in how this stage progresses and what it costs. Everything carried through the house costs more because it takes longer and requires more care to protect your floors and walls. Terraced houses with no rear access mean every tonne of soil and stone must travel through your hallway.

Digging out a patio creates a massive amount of heavy soil and rubble that needs to leave your property. A trader who carries waste must be a registered waste carrier, and you can check the public register to confirm their status. Checking their waste credentials is a sensible step.

The sub-base and why depth matters

The foundation of any paved area is the sub-base, which is a layer of compacted crushed stone, often called MOT Type 1, under the paving. A good rule of thumb for a patio sub-base is 100 to 150mm of properly compacted MOT Type 1. A depth of 100mm may suffice on firm, well-draining ground. A depth of 150mm is recommended on clay or softer ground, because clay holds water and shifts during winter freezes. A good landscaper should explain their chosen depth based on your garden soil.

The crushed stone is usually added in two 50mm layers to ensure it packs down tightly. The landscaper will rake each layer roughly level and compact it with a wacker plate or tamper. This heavy compaction locks the jagged pieces of crushed stone together so they cannot move, sink or slide.

If a landscaper skips this step, uses thin layers of loose rubble, or fails to compact the stone, the patio will eventually dip and crack under its own weight. The sub-base provides the structural strength of the entire project, making it the most important part of the build.

Bedding the slabs

Slabs must sit on a solid bed of mortar to hold them firm and spread the weight evenly into the sub-base below. One worked example uses a 25mm bed to support 50mm slabs. A basic patio mortar is four parts sand to one part cement or, as an alternative, 60mm of mortar on the base layer. The wet mortar bonds to the underside of the paving, locking it into position as it dries.

A common fault is slabs laid on a few dabs of mortar instead of a full bed. This practice leaves empty gaps under the paving. Rainwater gathers in these hidden voids, freezes during winter, expands and blows the joints apart. Spot bedding also leaves the corners of the slabs unsupported, making them highly likely to rock or snap when you walk on them. A landscaper should be able to explain their bedding method and avoid using dabs of mortar to save time or materials.

Falls and where the water goes

A perfectly flat patio will hold puddles after heavy rain. To prevent this, the surface needs a fall, which is the slight slope that sheds water in a specific direction. The water must run away from the house to protect your brickwork and stop your garden from turning into a swamp.

The exact angle required for a safe slope varies. One example aims for a 16mm drop per metre on standard non-textured slabs. This is not a universal rule, because the example applies to standard non-textured slabs, so ask your landscaper what fall they will use for your paving. The landscaper will set string lines across the site to guide this slope before they start laying.

In England, if you are paving more than 5 square metres of a front garden with an impermeable surface that does not drain to a permeable area, you need planning permission. Permeable surfacing does not need permission. You can replace or repair up to 5 square metres of existing hard surfacing, for example replacing paving slabs in an existing patio, without using permeable materials. You can read more about dealing with surface water on the Royal Horticultural Society website.

Height against the house and the damp-proof course

The damp-proof course is the waterproof layer in the wall of the house that stops ground moisture from rising up the bricks. It often looks like a thick black plastic line in the mortar joint near the ground. If the patio is next to the house, its surface needs to sit at least 150mm below the damp-proof course.

Paving built up against the house wall can bridge this waterproof layer and let damp cross into the wall. A good landscaper will identify the damp-proof course before they start digging so the final paving height sits well below it.

Jointing and how long before you use it

Filling the gaps between the slabs locks the patio together, stops weeds from taking hold and prevents water from washing the bedding mortar away. The jointing methods change depending on the gap width. Gaps under 5mm are swept with kiln-dried sand. Gaps of 5 to 10mm take a dry mix of one part sand to one part cement. Gaps over 10mm require a wet mix of four parts sand to one part cement.

Whatever the joint size or material used, you must wait at least 24 hours before using the patio. Walking on the slabs too early will break the mortar bond underneath and leave you with loose paving that shifts when you step on it.

Signs of poor workmanship

Bad paving is easy to spot if you know what to look out for. The most obvious signs appear during the groundwork and immediately after the first heavy rain.

• No visible sub-base beneath the paving
• Slabs laid on dabs of mortar instead of a full bed
• Artificial grass laid straight onto soil
• No fall so water pools or runs towards the house
• Puddles resting on the surface after rain
• Rocking slabs when you walk across them
• Uneven joints that look messy or crack easily
• Paving built up against the house wall
• No drainage thought given to where the runoff goes

You should also avoid doorstep callers offering cheap paving or leftover materials. Never agree to cash deals with no written specification, as you will have no proof of what was agreed if the paving fails.

What to put in the specification

Landscapers price per project after a site visit. The main cost drivers are area, groundwork, levels, access, waste removal, drainage and materials. A good quote states the excavation depth, sub-base depth, named materials, drainage plans and waste removal terms.

The table below shows typical groundwork and labour costs to help you understand a patio quote.

These are typical prices for 2026, and local quotes will differ depending on your garden. You should always check whether VAT is included in the price. London and the South East cost more. Typical timings run from around 2 days for a typical new patio to 3 to 5 days for a 20 square metre patio, so ask your landscaper how long your job will take. Larger jobs are usually paid in stages, and design fees are normally separate.

A quote is a fixed price, while an estimate is a rough guess. Citizens Advice suggests getting three written quotes, securing a written contract, paying deposits of no more than 25 per cent and paying by card. Under the Consumer Rights Act 2015, work must be done with reasonable care and skill. If not, the customer can ask for it to be put right or seek a partial or full refund. You might also be able to cancel within 14 days of agreeing a contract. If you end up in a dispute, point your complaint to Citizens Advice.

Landscaping is not a licensed trade, so vetted membership and evidence of past work matter. The British Association of Landscape Industries (BALI) says its Accredited members are vetted on workmanship, skill and health and safety. The Association of Professional Landscapers (APL) says members are assessed, regularly inspected and TrustMark accredited. TrustMark is the government-endorsed quality scheme. The Society of Garden and Landscape Designers (SGLD) is the professional body for designers. Membership is a good sign, not a guarantee.

Common questions

Do I need planning permission for a patio in the back garden?

Patios in back gardens are generally low-risk for planning, but nobody can say that any particular patio never needs permission. For comparison, decking in England is permitted development if it is no more than 30cm above the ground and, with extensions and outbuildings, covers no more than 50 per cent of the garden. These rights apply to houses, not flats or maisonettes, and listed buildings need consent for significant work. If you are unsure, you should check with your council.

Should I choose a patio or garden decking?

This depends on your budget and how your garden slopes. For decking, you need to distinguish between softwood, hardwood and composite boards and the frame beneath them. The better choice depends on your budget, how your garden slopes and the upkeep you are happy with, so ask for written quotes for both.

Can I lay artificial grass on my patio?

Artificial grass needs a proper foundation just like paving. Artificial grass laid straight onto soil is a common failure, as it will turn into a muddy swamp. It requires a compacted crushed-stone sub-base to drain properly and stay level.

What happens if a protected tree is near the patio?

A Tree Preservation Order makes it an offence to cut down, lop, uproot or damage a protected tree without the council's consent. Work on trees in a conservation area normally needs six weeks' notice to the council. Digging a patio sub-base too close to a protected tree can damage its roots and breach these rules.

How high can a garden wall or fence be around a patio?

In England, fences and walls can generally be up to 1 metre high next to a road or its footpath and up to 2 metres high elsewhere without needing planning permission. If you are also planning to pave a front garden, you can read more in our driveway planning guide.

Next steps for your patio project

Before you start contacting tradespeople, write down exactly what you want your garden to look like and what the space needs to do. Having a clear plan makes it easier to compare quotes.

• Decide on the size and purpose of the patio so the landscaper can suggest the right materials
• Ask three different landscapers for a site visit and a written quote
• Check that the quote includes excavation depth, sub-base depth and waste removal
• Ask to see examples of their previous work and check their waste carrier registration
• Agree a payment schedule with a deposit of no more than 25 per cent

Getting the groundwork right gives your new paving the best chance of coping with heavy rain and freezing winters. When you are ready to start gathering quotes, you can find a landscaper near you to discuss your plans and assess your garden.