Levels usually decide it. On ground that is level or near it, a patio is lower maintenance and longer lived. On a slope, decking spans the fall on posts and avoids the retaining walls and imported fill a level patio would need. Against the house, the damp-proof course constrains both — the finished surface must sit well below it.
- On a sloping plot, decking is often cheaper than the groundworks a level patio needs.
- Both must finish at least 150mm below the damp-proof course.
- Timber decking is a maintenance commitment; composite is not maintenance-free either.
- Shaded, north-facing decking gets slippery. That is the commonest regret.
Let the levels decide
This is the practical question that settles most cases before preference comes into it.
On level ground, a patio is straightforward: excavate, sub-base, bed, lay. Decking on the same ground means a sub-frame and posts to achieve a surface that the paving would have given you directly, so you are paying for structure you do not need.
On a slope, the arithmetic reverses. A level patio across falling ground needs either a retaining wall and imported fill on the low side, or excavation into the bank on the high side — and often both, plus drainage behind the retaining structure. That is a groundworks project. Decking spans the fall on posts and arrives level for a fraction of the work.
For a raised terrace off the back of the house, decking is usually the only sensible answer, because the alternative is a substantial retaining structure.
So before comparing materials, take levels across the area. The difference between a 200mm fall and a 600mm fall changes which option is cheaper, often decisively.
Side by side
| Patio | Timber decking | Composite decking | |
|---|---|---|---|
| Lifespan | Decades | 10–20 years with maintenance | 25+ years |
| Maintenance | Occasional wash | Clean and treat annually | Clean; no treating |
| Cost to install | Moderate | Lower on a slope | Higher than timber |
| On level ground | Best choice | Paying for unneeded structure | Same |
| On a slope | Needs retaining and fill | Spans it on posts | Spans it on posts |
| Slip in shade | Algae; cleanable | Can be genuinely slippery | Better, but not immune |
| Underneath | Solid | A void — needs ventilating | Same |
| Repair | Lift and relay slabs | Replace boards | Replace boards |
| Heat in sun | Stone gets hot | Comfortable | Can get very hot |
Our published guide figure for a patio is £80–£150 per m², material dependent. Decking costs vary more with the sub-frame than the boards, which is why the slope matters so much to the comparison.
The damp-proof course, for both
This applies whichever you choose and it is the detail most often got wrong against the house.
Any surface abutting the building must finish at least 150mm below the damp-proof course, with the fall running away. A surface laid level with the brickwork, or above the DPC line, gives water a path straight into the wall — and that shows up inside as damp which no internal treatment will fix.
It is a common problem precisely because patios get rebuilt on top of older ones, raising the level each time, and because people want a step-free threshold.
Where step-free access genuinely matters, the correct detail is an aco drain or a recessed channel immediately against the building, with the paving finished at threshold level but drained. That is a design decision, not something to improvise on site.
Decking has the same constraint but is easier to manage, because the deck surface can sit at threshold height while the structure below keeps clear of the brickwork.
Where decking disappoints
Worth being honest about, because it is usually the same three things.
- Slip in shade. A north-facing or overhung deck grows algae and becomes genuinely slippery in wet months. Grooved boards help less than people expect; what helps is sunlight, drainage and cleaning. If the area is permanently shaded, think hard.
- Maintenance that does not happen. Timber decking needs cleaning and re-treating roughly annually. Done, it lasts well. Not done, it greys, splits and rots, and most of the tired decking we are asked to remove is simply decking nobody maintained.
- The void underneath. It needs ventilating or the sub-frame rots from below, and it becomes a home for rodents if the perimeter is left open. Both are solvable at build stage and awkward afterwards.
- Composite is not maintenance-free. It does not need treating, which is the main advantage, but it still needs cleaning, it can still grow algae in shade, and cheaper boards fade and can get very hot in direct sun.
What good construction looks like
Patio
Excavation to a sensible depth, a compacted sub-base, and slabs on a full mortar bed rather than five dabs. Spot-bedding leaves voids that fill with water and crack or lift the slab in frost — it is faster, uses less material, and is invisible until the surface rocks. Falls away from the house at roughly 1 in 60 to 1 in 80, and a finished level well below the damp-proof course.
Decking
Posts on concrete pads or in sleeves, not simply pushed into soil. Joists at the correct centres for the board type — composite usually needs closer spacing than timber, and using timber spacings under composite causes bounce. A ventilated void, a weed membrane beneath, and all cut ends treated. Fixings appropriate to the board, and a perimeter detail that keeps animals out.
A third option: both
On a garden with a change in level, the arrangement that often works best is neither one nor the other.
A patio adjacent to the house, where you want the solidity and the easy connection to the kitchen door, with a deck further down the garden where the ground falls away and the sun is better in the evening.
This uses each material where it is strongest and avoids the expensive compromise of forcing one across the whole plot. It also breaks the garden into usable zones rather than one large expanse, which tends to look better on a modest plot.
The junction between them — usually a step, a low wall or a planting bed — is worth designing rather than leaving to chance.
What it costs
These are the landscaping figures published across this site:
| Job | Typical Coventry guide price | Notes |
|---|---|---|
| Patio | £80–£150 per m² | Material dependent |
| Day rate | £150–£250/day | Per landscaper |
| Landscaper, hourly | £15–£40/hr | Task dependent |
| Fencing | £80–£150 per panel | Supplied & fitted |
On a sloping plot, compare the patio figure plus the retaining and fill against decking plus its sub-frame. On level ground, the patio nearly always wins on whole-life cost.
We take levels first, because on a slope that usually answers the question before materials come into it.
Frequently asked questions
Is decking cheaper than a patio?
On level ground, usually not — you are paying for a sub-frame to achieve what paving gives you directly. On a slope it often is, because a level patio across falling ground needs retaining walls, imported fill and drainage, whereas decking spans the fall on posts. Take levels before comparing prices.
How far below the damp-proof course should a patio be?
At least 150mm, with the fall running away from the building. A patio level with or above the damp-proof course puts water straight into the wall, and that shows inside as damp no internal treatment will fix. Where step-free access matters, the right answer is a drainage channel against the building, designed in.
Is composite decking worth the extra?
Usually, if you would not reliably treat timber each year. It does not need treating, lasts longer and does not split. It is not maintenance-free though — it still needs cleaning, can still grow algae in shade, and cheaper boards fade and get hot in direct sun. Joist spacing is usually closer than for timber.
Why does my decking get so slippery?
Algae, which grows wherever the surface stays damp — north-facing, overhung or poorly drained decks especially. Grooved boards help less than people hope. Cleaning regularly, improving drainage beneath and cutting back overhanging planting all help. If the area is permanently shaded, a patio is the better choice.
What goes under a patio?
Excavation to a sensible depth, a compacted sub-base, and slabs bedded on a full mortar bed rather than five dabs. Spot-bedding leaves voids that fill with water and crack the slab in frost. None of it is visible once finished, which is exactly why it is the first thing a cheap quote cuts.
Can I have both decking and a patio?
Often the best answer on a garden with a change of level — patio by the house where you want solidity and an easy connection to the kitchen, decking further down where the ground falls away. It uses each where it is strongest and breaks a modest garden into usable zones.
Levels first, then materials
We take levels and check the damp-proof course before recommending either, because on a sloping plot that usually decides it. Free survey.