Plain-English answers to the questions we get asked most, written by the team that actually installs and services these systems, not a copywriter guessing. For the full evidence, calculator and printable cheat sheet, see The Healthy Home Humidity Guide.
What indoor humidity is healthy? Learn the 40-60% band, why 50-55% is a sensible target, what it does for mould and dust mites, and what it cannot do.
DiagnosisThree kinds of damp look alike but need different fixes. Use this four-rung ladder to tell rising, penetrating and condensation damp apart before you spend.
LeaksDamp patch under a gutter or after rain? Work up a four-rung ladder from a free walk-round to repairs, and learn when a dehumidifier will not help.
Everyday CausesMusty smell in a wardrobe or cupboard? A four-rung ladder from free checks to proper fixes, plus when a dehumidifier helps and when it does not.
Everyday CausesWet windows every morning? Learn what window condensation means, which rooms matter, and a four-step ladder from free habits to a proper fix.
MouldBlack mould in the corner of a bedroom is usually condensation on a cold wall. Follow this four-rung ladder to clean it safely, fix it and stop it returning.
Roofs and LoftsDamp roof timbers, wet insulation or a musty loft? Learn what causes loft condensation and how to fix it, in four rungs from cheap checks to specialist help.
VentilationIs your extractor fan doing anything? A four-rung ladder to check, clean, upgrade and ventilate properly so steam leaves the house instead of settling on walls.
Older PropertiesStains, salts or peeling paint on a chimney breast usually point to one of four causes. Work up a four-rung ladder from capping to specialist repair.
Older PropertiesSolid walls, sealed-up fireplaces and draught-proofed sash windows all change how moisture behaves in an older terrace, and why the fix isn't the same as for a modern estate house.
Everyday CausesA load of wet washing can put litres of water vapour into the air of a small house. Here's what actually helps, and what just moves the problem to a different room.
Looking for help near you? See the areas we cover around Chatham.