The short answer
Thermoplastic is a coloured plastic that is solid when cold and melts when heated. For playgrounds it comes as pre-cut sheets laid on clean, dry tarmac and melted with a gas burner, or is poured hot for long lines. It bonds as it cools, can be walked on within minutes and typically lasts five to ten years.
On this page
Thermoplastic is the same family of material as the white lines on most UK roads. On school playgrounds it is used for nearly every game, grid and graphic, because it lasts years where paint lasts months. This is what it is and how it goes down.
What thermoplastic is
A blend of resin binder, pigment, filler and glass beads that is solid at normal temperatures and becomes liquid when heated. Because the colour runs right through the material rather than sitting on the surface, it does not fade the way paint does as it wears.
Public buyers treat it as a distinct product. The Education Authority in Northern Ireland, for example, runs a framework for thermoplastic playground and line markings for its schools, split into three regional lots.
Preformed and poured
Preformed markings
Shapes, numbers and pictures are cut in a factory into sheets, delivered flat, set out on the playground and melted in place with a gas burner. This is how hopscotch, number grids, maps and logos are laid. It allows sharp detail and many colours.
Poured or sprayed lines
Long straight or curved lines, such as court lines and car park bays, are often applied hot from a wheeled applicator that melts the material in a heated tank. It is quicker for long runs but cannot do detailed shapes.
How a preformed marking is laid
- Clean. Sweep away grit, dust, moss, oil and old loose material.
- Dry. The surface must be dry; laying stops in rain.
- Prime if needed. Weathered tarmac, concrete and block paving get a fast-drying primer.
- Set out. The pieces are positioned to the layout drawing.
- Heat. The burner melts each piece until it flows into the texture of the tarmac.
- Bead. Glass beads are scattered on the hot surface for grip.
- Cool. A few minutes later it can be walked on.
Once heated and bonded, a piece cannot be reheated and moved, so the setting out matters.
Weather and surface
The two things that stop a job are a wet surface and a poor base. Thermoplastic bonds to sound tarmac and to old thermoplastic that is still firmly stuck down. It does not bond properly over paint or cold plastic, which must be removed first. Block paving can be marked, but the marking wears faster than on tarmac.
How long it lasts
UK contractors typically quote five to ten years on a school playground. The things that shorten it are cracked tarmac, grit and stones ground in by feet, vehicles and equipment dragged across, and snow ploughs or shovels.
| Thermoplastic | Paint | |
|---|---|---|
| Typical life on a busy playground | 5 to 10 years | under a year for games |
| Detail and colour | Sharp, multi-colour | Lines and flat colour |
| Grip | Glass beads fused in | Depends on the paint |
| Time before use | Minutes | Hours |
Is it safe?
Thermoplastic sits almost flush with the tarmac, so it adds no trip edge, and the bead finish gives grip in the wet. The safety issues are during laying: gas burners and molten plastic. That is a strong reason to have markings laid by a contractor rather than by a site team or volunteers.
Cost in brief
Supply-only preformed markings range from about £130 for a simple hopscotch to over £1,200 for a large periodic table, before VAT, from published UK price lists. Installed, single traditional games run from about £250, and full schemes into the thousands; public bodies also buy at scale, as when Enfield Council commissioned running circuits at a dozen schools. The price estimator gives a range for your own list, and our thermoplastic playground markings page covers what a good job looks like.
When you are ready, send the brief below and we will find a school playground markings contractor who covers your area.