Outdoor Wall Tiles: How to Choose Tiles That Don’t Fade or Crack in Sun & Rain

You have spent months building or renovating your home. You've likely put in a lot of time and effort picking out the designs that suit your style and preferences. Now that you have the walls and facade built for the home, it's time to dress the walls that will let the neighborhood and world see your home.

You pick out your tiles. You decide to go with stone, concrete, or even terracotta. The scaffolding gets taken down, and your home is exactly how you pictured it.

Then the rainy season comes. And then it rains again.

The once new tiles are faded; some have dark patches, some are light. Some have cracks; moss is growing on others. One even has a growing hairline crack.

This is all just from the rain. This was not from a bad installation. Indian tiles face a much different challenge than interior tiles.

This blog is the first step to educate you on the impacts tiles face if you choose the wrong outdoor wall tiles for Indian homes.

1. What Indian Outdoor Walls Actually Face

The different regions of India face different extreme weather. Your outdoor walls can be exposed to any one of them depending on where you live.

North and Central India: Delhi, Lucknow, Jaipur, Nagpur, Bhopal

North and Central India experience extreme summer heat. Summer temperatures can cause walls to heat above 60°C. Some walls are exposed to direct sunlight for 6 to 8 hours. This intense heat and sunlight can degrade quality tiles by breaking down surface pigments. It can cause tiles to fade, but it will not fade uniformly. The sun will impact some tiles more than others, causing uneven and patchy fading.

India's summers can be increasingly hot, and tiles can expand. Temperatures can significantly drop during the night. Following the extreme drop in temperature, those tiles will contract. The constant expansion and contraction will cause the grout joints to crack over time.

Coastal Cities: Mumbai, Chennai, Kochi, Visakhapatnam, Surat, Goa

The biggest factor for all coastal cities is air quality. Salt can be carried in the air and will begin to settle on surfaces. Salt particles will react with surfaces and will cause the degradation of both the tiles and the grout. Cheap ceramic tiles, used on facades, will show discoloration, efflorescence and deterioration in less than 3 to 4 years.

Mumbai experiences an extremely heavy and intense monsoon. The direct water load during peak monsoon can be 100mm in a single day. The exterior tiles must make sure no moisture is absorbed for the next three to four months of the monsoon.

South India – Hyderabad, Bangalore, Chennai interiors

The combination of high humidity and seasonal rainfall promotes moss and algae growth on wall surfaces. Moisture-trapping textured tiles are particularly impacted. Growth not only darkens the tile and makes it difficult to clean, but also makes walls look aged and neglected within a few years.

Hilly Regions: Shimla, Mussoorie, Coorg, Ooty

Temperature changes from warm to cold throughout the day and rain combined with frost create a freeze-thaw cycle that leads to stress. Water trapped within the porous tile grout expands and freezes. The alternating expansion and contraction is a grout and tile edge-damaging cycle.

Before picking outdoor wall tiles, the first question you should ask is not "what looks good?" but "what do the walls actually face?"

2. Water Absorption: The Most Important Number for Outdoor Wall Tiles

The monsoon season is a major consideration for the choice of outdoor wall tiles in India. Every tile has a water absorption rate, or the percentage of the tile's weight it can absorb in water.

Ceramic Tiles: Water Absorption 3–16%

Standard ceramic tiles, which are usually applied to indoor walls, have hygroscopicity ranging from 3% to 16%. On a protected, inner wall, tile absorption is not a problem; however, on an outer wall exposed to the elements (for example, a wall that faces direct, year-round, tropical monsoon rain), a 10% ceramic tile is completely saturated with water every year. During the dry season, when summer arrives after the year's monsoon, that absorbed water expands as the wall is heated. This results in cracking of the tile, cracking of the grout, and the deterioration of the wall surface.

Ceramic tile can be applied to outer walls that are, at least, partially protected. These are walls under a deep, overhanging roof, walls that are protected from direct rain, and walls with coping to protect the wall from water. However, for completely exposed outer walls, ceramic tile with high water absorption is not a viable option.

Glazed Vitrified Tiles (GVT): Water Absorption less than 0.1%

For completely exposed outer walls in the Indian subcontinent, GVT is the tile of choice. With water absorption less than 0.1%, monsoon rains will run off the GVT tile and will not be absorbed. In contrast, the tile body remains dry, even with water impacting the face. Additionally, the high-quality GVT tiles that are UV resistant will not fade, even with the harsh India sunlight.

For the Indian subcontinent coastal cities, full-body GVT will be the most durable option as it avoids the surface being attacked by the salt air.

3. UV Resistance: Why Some Outdoor Tiles Fade and Others Don't

Tile fading is a major problem for outdoor wall tiles in India. The wall looks like a different house after just a couple of years.

Some tile colors will fade after extended exposure to UV radiation. If a tile’s color only exists in the surface glaze (or print layer), the tile is even more susceptible to fading. When the glaze cracks, the body of the tile is revealed. This can be even more problematic if the body of the tile is a different and lighter color. This can lead to an uneven and patchy wall.

The main difference between standard tiles and UV-resistant tiles is the color stability when exposed to UV radiation. Good quality GVT tiles from reputable Indian manufacturers use glazes that are tested for UV-resistance. These tiles can hold their color for many years of exposure to the Sun.

What to check when buying outdoor wall tiles:

Make sure to ask the seller if the tile can be used on outdoor, fully exposed walls. What is the UV resistance level? If the tile is sold as only a "wall tile," there is a chance it has not been tested for sustained exposure to UV.

The best way to test the UV resistance of a tile is to ask for a sample that has been displayed outdoors for at least one year. If the color has changed significantly, it has insufficient UV resistance.

4. Why Do Outdoor Wall Tiles Crack? Tips for Prevention

When outdoor wall tiles crack, it’s mostly due to a bad installation. It’s not usually because the tiles themselves are bad. However, the wrong tiles can also add to a bad installation.

The Main Cause: Thermal Expansion

Outdoor wall tiles can crack from thermal expansion. In Indian weather, wall tiles can go from warm to cool in just a few hours and can also go through extreme temperature changes with the seasons. So, if the tiles are installed with no room to expand, the adhesive bond will fail, and the tile will crack and fall out.

How to Install: Expansion Joints

Expansion joints are a must for outdoor tile wall installations. Expansion joints provide a gap in the tile for the natural movement that the tile will go through. Instead of being filled with grout like the rest of the tile, these joints are usually filled with a flexible sealant. Usually, there is an expansion joint every 3 to 4 meters in both directions.

A lot of complaints that outdoor tiles crack are because the installer used the indoor tile installation method and skipped the expansion joints. Indoor tiles are not affected by temperature the same way that outdoor tiles are, which is why expansion joints are not needed.

The adhesive must be a flexible, weather-resistant adhesive.

Standard cement mortar adhesive cracks when it undergoes seasonal change. For outdoor wall tile installations, a flexible and weather-resistant tile adhesive must be used, which is rated for exterior use. This type of adhesive retains the bond integrity throughout all the temperature extremes that outdoor walls in India are exposed to.

It's common for many people to use standard interior tile adhesive for outdoor walls. This usually results in the tiles falling off the wall in a few monsoons, and is typically attributed to the tile adhesive failure. In reality, the tile adhesive was never designed for the application.

5. Moss, Algae, and Biological Growth: The Problem Nobody Mentions

Certain areas of India, like the coastal regions, South India, and certain hilly regions, are relatively humid and cause outdoor wall tiles to accumulate (usually unwanted) biological growth. Moss and algae, for example, use the moisture trapped in a textured surface and grout lines and colonize on the wall.

While this may be a hygiene issue for some, it is primarily an aesthetics issue. A green or black, biologically polluted wall, regardless of the quality of the tile, will make the wall appear neglected after a few years of construction.

Tiles with an Anti-Fungus Finish

Certain outdoor wall tiles are manufactured with an anti-fungus finish which, as the name indicates, prevents further biological growth on the tile. When seeking tiles to be used on walls in humid or coastal environments, ensure you ask for this specific product feature of an anti-fungal glaze.

Grout sealing

It's totally normal for grout lines to have biological growth (like mold or algae) because grout is porous. When installing grout in outdoor walls, waterproofing the grout after the grout is installed will help moisture not penetrate the grout joints. Waterproof grout is more resistant to algae and mold.

Surface texture choice

Smooth and lightly textured outdoor wall tiles are the best option to minimize biological growth in comparison to deeply textured surfaces. A highly embossed tile may look great in the showroom but will develop biological growth after one monsoon season on an outdoor wall in Kochi or Chennai.

6. Size and weight: what works on outdoor walls

Outdoor wall tile size can affect the finished look and how well the tiles stick over time.

Large format tiles: 600x1200 mm and above

Large format tiles create a seamless and popular look on external walls, but because they have fewer joints, they are more heavy and require a greater adhesive bond and careful installation to achieve a flat wall surface. These tiles can also pose a safety issue because of the great weight if a tile were to fall after the bond has failed, especially on walls greater than 3 meters or on a high-rise building. They are great for lower-height exterior walls and are great for feature walls, if installed correctly.

Medium-size tiles: 300x600mm

Of all the tile sizes, this is the most preferred for outdoor walls in Indian homes. These tiles also have the most design variety to create interesting wall elevation patterns. They weigh enough to be easily managed, have enough proportion to fit vertically and be less hassle when designing elevations, and are easily cut to fit around wall and window frame irregularities and drainage pipes.

Very small-size tiles: less than 200x200mm

Very small-sized tiles are the least preferred for outdoor walls.

First, they create water entry points which sustain biological growth, making them harder to maintain. Second, they are more dated and therefore less attractive.

7. Choosing Outdoor Wall Tiles by City and Climate

8. Choosing Outdoor Wall Tiles - Common Mistakes

Using indoor wall tiles for outdoor walls

The most common mistake. Indoor wall tiles are made to withstand no more than seasonal exposure to UV rays or monsoon flooding. They will look good for the first season and begin failing after the second year.

Choosing tiles based on showroom appearances

Showroom lighting can be very misleading. For example, how a tile looks under LED lighting, versus how the same tile looks on a south-facing wall in the harsher, May afternoon sunlight, can be very, very different. Always inspect tile samples in the sun, outdoor and natural light. The best option is actually putting the sample on the wall and inspecting it in natural sunlight at different times of the day. This is especially important before choosing your exterior tile.

Ignoring adhesive specifications

Tiles can only be as good as the adhesive that binds them. Regular adhesive that binds tiles for interiors is insufficient for outdoor walls. For tiles that will be fixed on outdoor walls, make sure to always choose weather-resistant, flexible adhesive.

Not including expansion joints

This is something that must be repeated, especially since it is the most common cause for cracking of outdoor wall tiles in the Indian climate. Expansion joints are essential for outdoor walls and are a structural necessity.

Why you shouldn't use dark colors on south and west-facing walls

In India, choosing tiles of a dark shade for south and west-facing exterior walls should be avoided. Tiles that are dark in color absorb a lot more sunlight, heat, and ultimately, stress. The tiles will go through thermal cycling more quickly in a harsher climate, and so will the adhesive. Therefore, it is safer and more sustainable to choose tiles that are mid to light in color.

Conclusion

Choosing external tiles in India is different from other countries in the world. Indian external tiles have to be structurally sound and resilient to harsh UV exposure, heat, and rain.

To appropriately select outdoor wall tiles, you must determine the conditions your wall endures. An example is GVT with water absorption below 0.1% for completely exposed walls, or a tile with UV-resistant glaze for sun-exposed walls. Walls in humid or coastal environments can use an anti-fungal finish. Weather-resistant, flexible adhesives can be used to set tiles. Also consider that expansion joints be placed every 3 to 4 meters to accommodate thermal movement.

When considering all these factors, it may not seem complicated, but these decisions must be made pre-installation because walls won't hold up forever with the wrong tile selection.

The right tile choice looks good for 15 to 20 years and only requires minimal maintenance to keep it looking good. The wrong choice will show its limits in just two monsoons.