Artificial Turf Infill: Types, How Much You Need and Which to Choose

Infill is the granular material brushed down between artificial turf fibres. It's easy to treat as an afterthought, but artificial grass infill does a lot of work: it holds the blades upright, weighs the turf down so it stays flat, protects the backing from sun, helps the turf drain, and on sports fields provides much of the cushioning. Picking the right one, and putting enough of it down, makes turf look and wear better.

The main types

• Silica sand. The standard for landscape turf. Cheap, heavy and stable. Use a rounded, washed, dust-free grade made for turf, not play sand or mason sand.
• Coated sand. Silica sand with an acrylic or similar coating, often coloured green and sometimes antimicrobial. Smoother on hands and knees, less dust, a little more expensive.
• Zeolite. A natural volcanic mineral with a honeycomb structure that holds ammonia molecules until rinsing washes them out. The go-to for dog areas, often mixed with sand.
• Crumb rubber (SBR). Made from recycled tires. Mostly used on sports fields for cushioning. It gets hot in sun and has been the subject of extensive study, including a multi-year US federal research program.
• EPDM, TPE and other elastomers. Virgin rubber or thermoplastic granules for sports fields; cost more, often run a bit cooler and come in colours.
• Organic infills. Cork, coconut fibre, walnut shell and blends. No plastic, cooler surface, but they need more upkeep and can float or break down.

Rules on plastic infill are changing in some places. The European Union's restriction on intentionally added microplastics will end the sale of polymer granular infill for sports fields there after a transition period ending in 2031. Canada has no equivalent rule today; sand and mineral infills used in home lawns aren't affected either way.

How much infill you need

Published rates from an Ontario turf supplier run about 1 to 2 pounds per square foot for home lawns, 2 to 3 for high-traffic and pet areas, and 3 to 5 for sports fields; a Toronto-area installer puts 2 to 3 pounds per square foot into a putting green. Your turf's spec sheet gives the exact rate for that product: taller, denser turf takes more.

That adds up quickly. A 500 sq ft lawn at 1.5 pounds per square foot needs 750 pounds of sand, fifteen 50 lb bags. The infill calculator does the arithmetic and rounds up to bags.

What it costs

HomeStars puts infill at $0.50–$2.50 per sq ft depending on the type. Plain silica sand is the cheapest; zeolite and coated sands cost more; specialty and organic infills more again.

How to spread it

1. Make sure the turf is dry, so infill doesn't stick to the fibres.
2. Brush the fibres up against the grain first.
3. Spread a thin layer with a drop spreader, not by shovel. Dumping piles leaves lumps and crushes fibres.
4. Brush it in with a stiff broom or power broom so it falls to the backing.
5. Repeat in thin passes until you reach the rate. The tips of the fibres should stay clear above the infill.
6. Rinse lightly to settle it.

Pet areas

For dog yards, a zeolite infill, alone or mixed with sand, makes the biggest difference to smell. It works by holding ammonia until a rinse flushes it out, so it needs regular hosing in summer. Some owners top up zeolite on the main pee spots each spring. See artificial grass for dogs.

Balconies and indoor turf

On balconies and rooftops, infill can wash into drains and add weight; many installers use light or no infill there. Indoors, infill tracks through the building, so most gym and facility turf is non-infill.

Topping up

Infill gets kicked into corners, washes toward low spots and slowly works into the base. Top up thin areas every couple of years, more often in high-traffic paths. HomeStars puts a whole-lawn top-up at $300–$800 every 2 to 3 years.

Infill and drainage

Infill sits between the fibres, so it affects how water reaches the backing. Clean, rounded sand drains freely. Fine, dusty sand and broken-down organic infill can clog the backing's drainage over time, which is one reason a lawn starts to puddle or smell after a few years. When you top up, use the same infill or a compatible one, and power-brush first so new infill mixes in rather than sitting on top.

Common infill mistakes

• Too little. Fibres flop over, wear faster and the backing sees more sun. Under-filling is far more common than over-filling.
• Too much at once. Dumping infill crushes fibres and leaves lumps; thin passes and brushing work better.
• Wrong sand. Play sand, mason sand and dusty sands compact and clog. Use a washed, rounded turf infill.
• Spreading on wet turf. Infill sticks to wet fibres and won't settle. Wait for a dry day.
• Skipping zeolite for dogs. Plain sand holds urine; an odour-control infill is the single most effective fix for smell.
• Infill on balconies. It washes toward drains. Use light or no infill there.

Infill for kids' play areas

Under play equipment, the safety comes from the shock pad, not the infill. Many playground systems use a sand infill to hold the fibres up; some are designed to need little or none. Follow the system's specification, keep infill topped up so fibres stay upright, and check under swings and slides, where feet scuff it away fastest.

Ask your installer which infill they used and keep a note of it, so top-ups years later match.