Damp in a rented home: a tenant's guide
Before arguing about who pays, you need to know the cause. A defect of the property and a problem of use are not solved the same way — and a report with photos and numbers changes the conversation with your landlord (senhorio).
Who pays, as a rule
As a rule, maintenance work on the property falls to the landlord (Código Civil — Civil Code — art. 1074), who must ensure the home can be used for its purpose (art. 1031). Problems caused by use — drying clothes indoors without airing, extractor fans switched off — may be the occupant's responsibility. The lease may have its own clauses.
How to document before writing
- Dated photos: a wide shot, a close-up and the room's window.
- Humidity readings at 7 am and at night for 1–2 weeks (a hygrometer costs about €10).
- Your humidade.pt diagnosis report, with the likely cause and probabilities.
- Dates: when it appeared, when it got worse, when you first told the landlord.
- What you've already done: airing, a dehumidifier, moving furniture — and the result.
Step by step
- 01Take the diagnosis to find the likely cause (3 minutes, no email).
- 02For 1–2 weeks, air the home, don't dry clothes in the bedroom and log the humidity.
- 03If the likely cause lies with the property (water ingress, rising damp, a building defect), send the letter to your landlord with the report.
- 04Send it by registered post with proof of receipt or by email with read receipt, and keep a copy.
- 05If there's no answer within the deadline, get advice (DECO, a lawyer, Julgados de Paz). Don't stop paying rent on your own initiative.
Letter to the landlord
Fill in the fields, then copy, email or print. The letter is in Portuguese because it goes to a Portuguese landlord. You can also create it pre-filled from your diagnosis result.
03/10/2026 Exmo(a). Senhor(a) [nome do senhorio], Venho por este meio informar que o imóvel sito em [morada], de que sou arrendatário(a), apresenta humidade em: [divisões], há [duração]. Solicito que seja agendada uma visita técnica para avaliação da causa e reparação, no prazo de 15 dias a contar da receção desta comunicação. Com os melhores cumprimentos, [o seu nome] [contacto]
Notification template — not legal advice. Send it ideally by registered post with proof of receipt (carta registada com aviso de receção) or email with read receipt, and keep a copy.
Read next
Frequently asked questions
Withholding rent on your own initiative can backfire and may even justify ending the lease. The safe route is to document, notify the landlord in writing with a deadline and, without an answer, get legal advice or contact DECO.
They may be partly right: condensation depends a lot on habits. Log the humidity for two weeks while airing every day. If it stays above 70% in the morning, or the patch shows signs of water ingress or rising damp, there is a problem with the property.
It is a written notice: it proves the landlord was told, when and with what information. It is not a legal document and doesn't replace advice. Send it by registered post with proof of receipt so you can prove it was sent.