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“The wick house”
Rising damp: signs, causes and treatments
Water from the ground climbs the walls as if through a wick. It shows up on ground floors and in basements, in a band up to about one metre high. It is the most expensive treatment — and the one most often sold to people who don't need it.
Signs
- Damp band up to ~1 m from the floor
- White powder and salts (efflorescence)
- Crumbling plaster, blistered paint
- Ground floor or basement, the same all year round
rising from the ground
Most common causes
Walls with no barrier against ground moisture, outside ground level higher than the floor inside, cement renders that stop the wall from drying out.
Treatments and observed prices
- Silane injections€35–60/m²
- Electro-osmosis€35–60/m²
- Whole-house systems (customer reports)€4,500–20,000
Sources: Habitissimo, Zaask, cume.pt, customer reports. Collected on 02.10.2026.
Read next
How much does rising damp treatment cost? (2026 prices)
Injections vs electro-osmosis vs plaster: an independent comparison- Damp in basements and ground floors: rising damp, condensation or the ground?
Written by the humidade.pt team · Reviewed by a civil engineer (to be confirmed) · Updated October 2026