How Weathering Changes Brick Colour and Texture

An old brick rarely looks exactly as it did when it left the kiln. Sunlight, rain, frost, airborne dirt, biological growth, salts, mortar staining and repeated cleaning can all change the visible surface. This is one reason a photograph of an existing wall can produce a misleading colour match.

Sun and exposure

Different elevations weather differently. A sheltered elevation may retain a stronger surface colour while an exposed face becomes lighter, duller or more textured. Repairs made at different times can therefore contain bricks from the same or similar range that now appear noticeably different.

Rain and moisture

Wet brick normally appears darker and can show stronger colour contrast. Moisture can also make surface texture more obvious. Compare bricks when they are dry where possible, and avoid using a wet wall as the only colour reference for ordering a replacement.

Biological growth and staining

Algae, moss and general environmental deposits can alter the apparent colour. Chimney areas, low walls and sheltered joints may show different staining patterns from upper elevations. White or pale deposits can also occur where salts migrate through masonry. These surface effects should not automatically be interpreted as the original brick colour.

Cleaning can change the evidence

Pressure washing, chemical cleaning, abrasive treatment and repointing can expose a different surface from the one that was previously visible. Cleaning may remove a weathered skin, while aggressive methods can damage the face of a brick. For historic work, identify and record the existing surface before deciding whether cleaning is appropriate.

How to match colour properly

• Compare several bricks, not a single stained unit.
• Use natural daylight where possible.
• Compare texture and firing variation as well as base colour.
• Look at sheltered and exposed areas separately.
• Check whether the brick is wet, painted or heavily stained.
• Obtain a physical sample before ordering a large quantity.

Why screens are unreliable

Phone cameras and displays apply exposure, white balance and colour processing. Two people can photograph the same brick and obtain different-looking images. A catalogue photograph is also controlled lighting rather than a guarantee of what the brick will look like in a particular wall.

Use Find My Brick to build a shortlist, and use the replacement brick guide for the next checks.