Dirty white wall with black and brown mold spots and stains.

Signs you have a

Cold walls or condenstion

problem

you don’t need a moisture meter to know something isn’t right.

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Signs you have a Cold walls or condenstion problem

Icons with text describing how to prevent mold: a hand touching a wall, a spring with foam, a window with condensation, and a cloud with rain. Text reads: "Walls that feel cold or damp to touch," "Black spots or mould behind furniture," "Condensation on windows every morning," and "Musty smells that never go away."

if you recognise 2 or more of there, it’s worth having us take a look.

Why Are My Walls So Cold?

Most older homes in Bristol were built with solid brick or block walls and have little to no insulation. This means heat escapes quickly through the external walls, leaving the inside surface cold.

When warm, moist air from cooking, showering, drying clothes and even breathing touches a cold surface, the moisture turns into water droplets. Over time, this leads to:

  • Cold internal wall surfaces

  • Damp patches

  • Mould growth

  • Peeling paint or bubbling plaster

  • Rooms that feel colder than the rest of the home

New windows and doors can also trap moisture inside, making condensation worse.

What’s Actually Happening

Cold walls are the result of heat loss + moisture in the air.

  • Warm air always moves toward colder surfaces

  • As the warm air cools, it reaches dew point

  • Moisture drops out of the air and settles on the cold wall

  • This repeated cycle causes damp, staining and mould

In short, your walls are cold because they’re uninsulated, and condensation forms because the air inside your home holds more moisture than the walls can handle.

The good news: this is fully fixable, and once the wall surfaces stay warm, condensation and mould disappear.

MAINCO’s Long-Term Fix for Cold Walls & Condensation

Icons representing ventilation and home improvement with text about ventilation advice and a fresh look outside at a home.
An infographic illustrating insulation solutions. On the left, a diagram of an external wall with arrows indicating insulation stopping heat escaping. Text below reads: 'External Wall Insulation: A new layer stops heat escaping, keeping your rooms warm and comfortable.' On the right, a brick wall with tools (a trowel and screwdriver). Text below reads: 'Render & Damp-Related Works: Problems like mold and condensation are resolved for the long term.'
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