The short answer
They suit different jobs. Decking creates a raised, level platform that is ideal for seating, dining and uneven or sloping ground, and composite decking in particular needs little maintenance and lasts well. Timber decking is cheaper but needs regular cleaning, oiling or staining and can get slippery with algae in a damp British climate. Artificial grass gives a soft, green, play-friendly surface that stays usable in all weather and needs only occasional brushing, but it has a finite lifespan of roughly 10 to 20 years and can get hot in summer sun. On a level garden the two are alternative finishes; on a slope or where you want a raised seating area, decking has the structural advantage. Many gardens combine a decked seating zone with an artificial lawn for play.
Artificial grass and decking are often weighed against each other for the same patch of garden. The right answer depends on the ground, how you use the space and how much upkeep you want. Here is the comparison.
Grass vs decking
- SurfaceSoft green vs hard timber/composite
- Sloping groundDecking better
- Children's playGrass better
- Timber upkeepRegular; composite low
- Slip riskTimber can be slippery wet
Cost, maintenance and lifespan
Cost depends heavily on the type of decking. Timber decking is relatively affordable to install but carries ongoing upkeep — cleaning, and re-oiling or staining every year or two to keep it sound and looking good. Composite decking costs more upfront but needs far less maintenance and resists rot, splitting and fading. Artificial grass sits in a comparable upfront bracket once its base is prepared, with low ongoing upkeep limited to brushing and rinsing.
On lifespan, composite decking and good artificial grass both last well, though grass faces eventual replacement after roughly 10 to 20 years as the fibres wear or fade. Timber decking lasts as long as it is maintained but degrades faster if neglected, especially in wet, shaded UK gardens prone to algae and rot.
| Factor | Artificial grass | Decking |
|---|---|---|
| Surface | Soft, green | Hard, flat platform |
| Sloping or uneven ground | Needs levelling | Built-in level frame |
| Upfront cost | Comparable once based | Timber lower; composite higher |
| Maintenance | Brushing, rinsing | Timber high; composite low |
| Slip risk when wet | Low | Timber can be slippery |
| Children's play | Soft, suitable | Hard, splinter risk on timber |
| Lifespan | Roughly 10–20 years | Composite long; timber if maintained |
Indicative comparison for a UK garden. Sources: RHS, Checkatrade.
Safety, drainage and slope
Decking shines where the ground is uneven or sloping, because the supporting frame creates a level platform without major earthworks. That makes it a strong choice for a raised seating area, a deck off the house, or a garden that falls away. Artificial grass, by contrast, needs the ground levelled and a compacted base built up, which is more work on a slope.
Safety and drainage differ too. Timber decking can become slippery with rain, algae and moss, so it needs grooved boards or anti-slip treatment and regular cleaning; composite boards are generally more slip-resistant. Decking drains through the gaps between boards. Artificial grass is soft and grippy underfoot and drains through its permeable backing into the base below, which is why it is the more forgiving surface for children and pets.
Which suits which garden
Decking is the better fit for a defined seating or dining zone, a raised area, a garden on a slope, or a space against the house where you want a flat platform that takes furniture and a barbecue without harm. Composite is the low-maintenance, long-life option; timber is the budget route if you accept the upkeep.
Artificial grass suits the part of the garden you want soft and green: children's play, a lawn-like outlook, and level areas where a hard platform would feel out of place. As with paving, the strongest gardens often zone the space — decking where you sit, artificial grass where you play — rather than committing the whole garden to one surface.
Appearance, feel and combining the two
The two surfaces create quite different moods. Decking gives a structured, architectural feel, with the line of the boards leading the eye and a warm, natural timber look or the clean, consistent appearance of composite. It works well as a defined platform that reads as an outdoor room. Artificial grass gives a soft, informal, green expanse that reads as lawn and softens a garden, which is why it suits the areas between and around the harder features rather than as a deck-like platform.
Underfoot, the contrast is obvious: decking is solid and flat, good for furniture and standing, while grass is soft and forgiving, good for sitting, lying and children playing. Both can warm up in summer sun — dark composite boards and dense grass fibres alike — so neither is automatically the cooler choice. In winter, timber decking is the one to watch, as it can become slippery with frost, rain and algae, whereas artificial grass stays grippy.
Because they complement each other, combining the two is a common and effective approach. A raised deck off the house for dining and seating, flowing down to an artificial lawn for play and greenery, gives a garden both a usable hard platform and a soft area, with each surface placed where it performs best. Planning that layout from the start, including how the deck steps down to the grass and how the edges meet, produces a more coherent result than retrofitting one surface against the other later. The decision is therefore less about which is better in the abstract and more about which suits each part of your particular garden and how the two can work together.
Maintenance habits are worth weighing honestly before you commit, because they differ by material. Timber decking asks for the most attention: an annual or biennial clean and a re-coat of oil or stain to keep it sound, plus vigilance against algae in damp, shaded spots. Composite decking needs far less, usually just an occasional wash. Artificial grass sits between the two for effort, needing periodic brushing, rinsing and leaf clearing but no coating or sealing. If you want the lowest possible upkeep, composite decking and artificial grass are the front-runners; if budget rules out composite, the choice becomes timber decking with its maintenance routine versus artificial grass with its lighter one, which often tips the balance towards grass for the areas where a soft surface suits.
Frequently asked questions
Is artificial grass cheaper than decking?
It depends on the decking type. Timber decking is often cheaper upfront than a fully based artificial lawn, while composite decking usually costs more. Once you factor in the ongoing maintenance of timber decking, the long-term costs narrow. Neither is reliably cheaper across the board.
Can you lay artificial grass on top of decking?
Yes, artificial grass can be laid over a sound, level deck, often using a non-infill grass and ensuring water can drain through the board gaps. The deck must be solid and the surface prepared so the grass sits flat. It is a common way to soften an existing deck without rebuilding it.
Which is better for a sloping garden?
Decking generally suits a slope better, because its supporting frame creates a level platform without major excavation. Artificial grass on a slope requires the ground to be levelled and a compacted base built up, which is more labour. For uneven or falling ground, decking is usually the more practical surface.
Sources & further reading
Figures on this page are typical UK ranges drawn from published cost guides and are intended as guidance, not a quotation.