Road markings in Saudi Arabia, the UAE, Africa, Southeast Asia and other hot regions face conditions that differ from those in moderate climates. Pavement temperatures can rise far above air temperature, while strong sunlight and heavy traffic increase the risk of softening, deformation, dirt pickup and color change.

Selecting a hot-climate thermoplastic paint therefore requires more than choosing a product described as heat resistant.

Why Hot Pavement Creates Problems

Thermoplastic material is designed to soften during controlled heating and harden after cooling. If the finished marking begins to soften excessively under service temperatures, tires can deform the line or press dirt into the surface.

Potential hot-climate failures include:

· Flattened or distorted profiles

· Tire tracking and surface deformation

· Increased dirt pickup

· Loss of clean line edges

· Premature bead embedment changes

· White or colored pigment degradation under UV exposure

· Asphalt bleeding through the marking

Softening Point vs Application Temperature

These two temperatures describe different conditions.

· Softening point indicates when the finished material begins losing rigidity as temperature increases.

· Application temperature is the much higher temperature used to melt and install the material.

A product may be applied at 180–220°C but have a softening point around 90–125°C, depending on formula and test method. The required value should be selected according to the tender and verified through testing.

Key Selection Factors

Maximum Pavement Temperature

Do not rely only on average air temperature. Dark asphalt exposed to direct sunlight can become significantly hotter. Obtain local road-surface data when possible.

Traffic Load

Slow-moving heavy vehicles apply more stress than free-flowing passenger traffic. Intersections, port roads, toll areas and industrial sites may need greater deformation resistance.

Resin and Additive System

The binder, wax, plasticizer and aggregate balance affects flow during construction and stability after cooling. A formula that is too soft may install easily but deform in service.

Marking Thickness and Profile

Thick or profiled markings can retain more heat. Their geometry should be tested with the intended machine and traffic conditions.

Pigment and UV Stability

Yellow, red, blue and green markings require pigments selected for heat and UV exposure. Ask for relevant color and weathering tests rather than relying only on a color sample.

Pavement Type

Fresh asphalt, surface treatments and emulsions can react differently to hot-applied material. TxDOT notes that extreme heat from sprayed thermoplastic may bring asphalt emulsion to the marking surface.

Recommended Project Data

Application Practices in Hot Regions

Do Not Automatically Increase Kettle Temperature

High outdoor temperature does not mean the paint should be heated above its TDS range. Overheating can damage resin and pigments.

Monitor Pavement Conditions

Record pavement temperature as well as air and material temperature. Extremely hot pavement can change cooling time and bead embedment.

Control Traffic Opening

Do not reopen the road based only on an assumed three-minute cooling time. Confirm that the marking is hard enough for the actual pavement temperature and thickness.

Inspect Asphalt Bleeding

Test a small area when the pavement is new, contains emulsion or has shown bleeding during hot weather.

Protect Materials Before Use

Store bags in a cool, dry place away from direct sunlight and moisture. Damaged packaging can affect flow and consistency.

Common Purchasing Mistakes

· Asking only for heat-resistant paint without stating the pavement temperature

· Selecting only by price per ton

· Ignoring heavy-truck and turning traffic

· Using a temperate-climate sample for desert projects

· Requesting compliance without identifying the standard edition

· Ordering a full container before an application trial