FAULTNEST DAMP & MOULD
Damp, Mould & Condensation Guides
Identify whether moisture is caused by condensation, leaks, penetrating damp, rising damp, poor ventilation or cold surfaces.
Find the moisture source before decorating
Painting over mould or damp rarely fixes the cause. Check ventilation, leaks, external defects and hidden moisture before applying treatments.
Read FaultNest safety guidance →BROWSE GUIDES
Choose the problem
Open the section that matches the fault, then choose the individual troubleshooting guide.
Condensation problems Windows, walls, ceilings and cold surfaces.
Condensation on Windows
Reduce indoor moisture and improve ventilation.
Condensation on Walls
Check cold bridges, airflow and humidity.
Condensation on Ceiling
Inspect insulation, ventilation and moisture sources.
Condensation in Bedroom
Manage overnight moisture and cold surfaces.
Condensation in Bathroom
Improve extraction and heating.
Condensation in Loft
Check ventilation, insulation and vapour movement.
Mould growth Black mould, recurring spots and musty areas.
Mould Around Windows
Clean safely and fix condensation or seal failures.
Mould on Bedroom Wall
Check humidity, furniture spacing and cold bridging.
Mould on Bathroom Ceiling
Improve extraction and surface drying.
Mould Behind Furniture
Increase airflow and check wall temperature.
Mould Keeps Coming Back
Find the underlying moisture source.
Musty Smell in a Room
Trace hidden damp, fabrics and poor ventilation.
Penetrating damp External walls, roofs, gutters and failed seals.
Damp Patch After Rain
Check gutters, roof defects and wall penetration.
Damp Around a Window
Inspect sealant, flashing and drainage.
Damp on Chimney Breast
Check flashing, caps, salts and ventilation.
Damp on External Wall
Inspect render, pointing and drainage.
Water Stain on Ceiling
Trace roof, bathroom or pipe leaks.
Damp Under Window Sill
Check seals, sill drainage and wall defects.
Low-level damp and salts Skirting, plaster and moisture near floor level.
Damp at Bottom of Wall
Check bridging, leaks and ground levels.
Skirting Board Damp
Inspect wall moisture and plumbing nearby.
White Salts on Wall
Recognise efflorescence and moisture movement.
Paint Bubbling Near Floor
Check damp, salts and failed finishes.
Plaster Crumbling Near Floor
Assess prolonged moisture and salt damage.
Is It Rising Damp?
Separate rising damp from condensation and leaks.
Ventilation and humidity Extractor fans, airflow and moisture control.
Room Humidity Too High
Identify moisture sources and ventilation needs.
Extractor Fan Not Clearing Steam
Check airflow, ducting and fan performance.
Air Vents Causing Draught
Balance ventilation with comfort.
Dehumidifier Not Reducing Humidity
Check sizing, temperature and water ingress.
Best Humidity Level for a Home
Understand useful indoor humidity ranges.
How to Ventilate a Room in Winter
Reduce moisture without wasting excessive heat.
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