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Damp diagnosis report

CONCLUSION

Your home is

«The sweating house»

The air is loaded with water and the walls are cold. The house sweats — in the corners, behind the wardrobe, on the windows.

Likely condensation

Confidence highSeverity medium

Condensation98%

Rising damp0%

Water ingress2%

Why we think so

Hábitos: dries laundry indoors, rarely airs the home, extractor fan in one room only
Wall at 13,0 °C, below dew point + 1 °C (13,7 °C)
Black mould spots in the upper corners or behind furniture

18.0 °C · 76% RH → dew point 13.7 °C · wall 13.0 °C · RH at the wall 100%

NEXT STEP

As a tenant you don't need to hire a company: you need to notify the owner, with the report and photos.

Free. You don't need a company for this.

01Air the home for 5–10 minutes morning and evening with windows on opposite sides open (a short through-draught, not a window left ajar all day).
02Move furniture 5–10 cm away from outside walls.
03Dry laundry outdoors, or in a room with the window open and the door closed.
04Run the extractor fan while you shower and for 15 minutes afterwards.
05Clean the mould with diluted bleach (1:4), wearing gloves and a mask. Do not paint over it before the cause is fixed.

Digital hygrometer

To find out whether the morning humidity goes above 70%.

€10–20

Infrared thermometer

Measures the wall so you can compare it with the dew point.

€20–30

Dehumidifier 10–12 L/day

For bedrooms where airing is not enough.

€150–250

Moisture absorbers

For wardrobes. They won't fix a whole room.

€5–15

For condensation, area of 1–5 m², Lisboa.

Do it yourself (dehumidifier, moisture absorbers, hygrometer)€20–300

Positive input ventilation (PIV / VMI) in an apartment (estimate)€800–2 500

Mechanical ventilation (MVHR / VMC)≈ €2 500

Ranges observed on Habitissimo, Zaask, cume.pt and customer reports (Oct 2026). Real prices depend on the technical visit.