Artificial grass problems: heat, smell, drainage, joins and how to avoid them

We sell artificial grass and we would rather you knew what goes wrong with it before you order than after. Most problems come from the base it is laid on and how it is looked after, not from the grass, and nearly all of them are avoidable. This guide lists the ten we are asked about most, says why each happens in a British garden, and gives the fix.

The short answer

The problems that matter are heat in full sun, smell from dog urine, drainage on a bad base, flattening under furniture, joins that show, weeds at the edges, moss in shade, and melting from reflected sunlight off windows. Build a proper sub-base, use sand infill, brush it monthly, and rinse where the dog goes, and you will not meet most of them.

1. It gets hot in the sun

Why: plastic fibre absorbs more heat than living grass. On a hot, still afternoon a dense dark pile in full sun can be uncomfortable barefoot. Fix: hose it for ten seconds and it is cool for an hour; choose a lighter green for a south-facing garden; a parasol over the seating area. This is a handful of days a year in most of the UK.

2. It smells when the dog uses it

Why: urine that cannot drain sits in the base and warms up. This is a drainage problem, not a grass problem. Fix: a free-draining sub-base of 50mm of MOT type 1 and 25mm of sharp sand, no membrane directly under the grass, a rinse with the hose once a week where the dog goes, and an enzyme cleaner monthly. Done right it never smells. The dogs guide has the routine.

3. It puddles after rain

Why: the grass drains at hundreds of litres per square metre per hour; the base underneath it does not. Grass laid straight onto clay soil or an old patio with no fall holds water. Fix: the sub-base above, compacted, with a slight fall. On concrete or decking, use a drainage underlay or lay it with a fall to an edge; see laying on decking and concrete.

4. It flattens where you walk and under furniture

Why: every pile flattens under weight. Cheap straight fibres stay flat; shaped fibres spring back. Fix: sand infill (4 to 5kg per square metre) holds the fibres upright, a stiff brush against the pile once a month lifts them, and a C-shaped fibre like Val recovers on its own. Move furniture occasionally.

5. The join shows

Why: two pieces with the pile leaning different ways, a gap or an overlap, or tape that lifted. Fix: choose a roll width that avoids a join where possible (the roll widths guide), lay both pieces with the pile the same way, butt the edges with a fibre-width gap, and use proper joining tape and adhesive on a dry day. A good join is invisible.

6. Weeds at the edges

Why: weeds cannot grow up through the backing, but seed lands on top and roots into the sand infill, and they creep in at unsecured edges. Fix: weed membrane under the sub-base (not directly under the grass), edges pinned or fixed to a timber or composite edge, and a pull or a spray of weedkiller on anything that appears. Far less than a real lawn.

7. Moss and algae in shade

Why: a north-facing lawn under trees stays damp, and damp grows moss on any surface. Fix: improve drainage, sweep leaves before they rot, and treat with a moss killer safe for artificial grass in spring. Brushing after treatment clears it.

8. It melted in a patch

Why: the one people do not expect. Sunlight reflected off a south-facing window, a conservatory, a mirror or a stainless barbecue focuses enough heat to melt fibres in a stripe. It happens on hot, clear days and looks like a burn. Fix: find the reflection at midday in summer; a window film, an awning or moving the mirror solves it. Dropped barbecue coals and cigarette ends melt fibres too; a mat under the barbecue. Melted patches can be cut out and a piece let in.

9. It fades

Why: ultraviolet light breaks down cheap, unstabilised fibre. Fix: buy a grass with a UV warranty. All ours carry a ten-year UV guarantee and are stabilised in the yarn, not sprayed on. A slight settling in the first summer is normal; ongoing fade is not.

10. Static and pet hair

Why: dry plastic fibre holds a static charge, which grabs hair and fluff. Fix: sand infill earths it and a hose removes it. A garden vacuum or a plastic rake lifts hair; a stiff brush does the rest.

Problems you will not have

Mowing, feeding, watering, bald patches, mud in the house, hay fever from the lawn, and a garden that looks dead in August. Those are what the grass was invented to remove, and it does.

Before you buy

1. Plan the sub-base before the grass; it decides drainage, smell and how level the lawn looks.
2. Check the garden at midday in summer for reflections off glass.
3. Pick a shaped-fibre grass in a mid pile for a family garden: Dan, Val or Rum.
4. Budget for sand infill and a stiff brush; they are what keep it looking new.
5. Order free samples and leave them outside a week. The cost guide prices the whole job, base included.