Cool Roof Tiles in Bengaluru: Keep Your Terrace and Rooms Cooler

If you live on the top floor or in an independent house, you know how hot the rooms under the terrace get on a March or April afternoon. A bare concrete slab soaks up the sun all day and releases heat into the room below well into the night. Cool roof tiles are white, highly reflective tiles laid on the terrace to bounce much of that sunlight back.

What cool roof tiles are

Cool roof tiles are usually white vitrified or ceramic tiles with a special glaze or surface that has high solar reflectance. They reflect a large share of sunlight and also release absorbed heat quickly. Their performance is often described by SRI (Solar Reflectance Index). A higher SRI means the surface stays cooler in the sun.

They are usually somewhat thicker than indoor tiles and have a matt or lightly textured surface, since terraces get wet and people walk on them.

Where they work, and where they don't

Good fit:

• Open terraces of independent houses and villas
• Roof slabs above top floor apartments (with the society's agreement)
• Roofs over staircase headrooms, sheds and utility rooms
• Commercial roofs where the space below is used

Limits to know:

• They reduce heat gain but do not replace insulation or waterproofing
• Dust and algae reduce reflectance. A dirty grey tile does not perform like a clean white one, so wash the terrace periodically
• They are bright white, so glare can be strong in afternoon sun. Some people use them on the open roof and a different tile in a sit-out area
• For a terrace garden or seating area, a regular anti-skid or outdoor tile may be more comfortable visually

Sizes and finishes commonly available

Cool roof tiles typically come in 300x300 mm, sometimes 400x400 mm or 600x600 mm. Small sizes are common because they follow the terrace slope and handle thermal movement better. The finish is usually matt white with a light texture.

How to choose and lay them

1. Ask about reflectance. If the box lists SRI or solar reflectance, compare it. Higher is better.
2. Fix waterproofing first. Repair cracks and get the terrace waterproofed before tiling. Tiles go on top of that layer.
3. Keep the slope. The tile bed should keep a proper slope to the rain water outlets so water does not stand.
4. Use exterior grade adhesive and grout. Terraces see big temperature swings. Leave movement joints, especially around the parapet edges.
5. Plan to clean. A wash before and after the monsoon keeps the surface bright and reflective.
6. Check grip. A light texture is safer when the terrace is wet.

Our terrace page covers other options for open roofs.

Measure your terrace

Measure the terrace area and note where the outlets are. Call the shop or visit us to check which cool roof tiles are in stock and get the right quantity worked out.