Moisture, both rising and environmental, is a frequent subject of "clash" between the building owner and the tenant. In this article we try to clarify rights and duties of both parties.

Owner and tenant obligations:

When renting a property, it must be delivered livable and without defects. The lessor, in fact, is required by law to deliver to tenant a property in good condition, well maintained and such to serve the stipulated use for the entire contract duration.
On the other hand, the tenant is required to keep the property in good condition and return it in the same state it was received.
Every year, thousands of tenants have to manage the humidity problem at home. In fact, it may happen that, after some time, humidity problems and mold begin to appear. Obviously disputes arise, concerning responsibility attribution, and consequently very often quarrel and lawsuits for the expenses required to eliminate rising damp, environmental humidity and mold

Whose responsibility is it in case of environmental humidity?

First of all, we need to understand the type of problem; the diagnosis is quite simple: when there are black spots (which are only molds, spores and bacteria) in ceiling corners we have a problem of environmental humidity or condensation. In this case, the owner is absolutely not responsible for the phenomenon, as mold is caused by insufficient space ventilation (environments where more water vapor is produced, such as bathrooms and kitchens, are more susceptible to mold). The tenant, in addition to removing any molds and spores and aerating the rooms as much as possible, can ask the lessor to purchase controlled mechanical ventilation equipment (see KontrolAIR), which supports and optimizes air recirculation in the rooms. In these cases the equipment, as installed in the walls, remains property of the lessor.

The situation is different, whether it is rising (or capillary rising) damp

In cases of rising damp, the responsibility instead lies with the lessor. Insufficient insulation from the ground is obviously impossible to impute to the tenant, and therefore the owner is obliged to rehabilitate degraded masonry. The subsoil water is canalized within the capillaries in the masonry; over time, water inside the walls tends to evaporate, letting salts come out, which, in addition to causing bulges and cracks on plaster, form mold spots, making the room aesthetically unpleasing and unhealthy. When buildings are inhabited, it is often impossible to insulate walls from the ground properly, as the works are very invasive and above all very expensive, unless you opt for a simple, non-invasive and above all definitive solution, such as electrophysical dehumidification (see KontrolDRY).  

Termination of the contract in case of rising damp or mold

Art. 1578 of Italian Civil Code states: “The landlord shall compensate the tenant for the damage deriving from vices in the thing, unless he can give evidence that he was not aware of them without any fault upon delivery.”. If there is no agreement to carry out rehabilitation works and if habitability is compromised, the tenant may request a reduction in the rent fee, or even termination of the contract, with claim for damages. In these cases, legal action is often taken. It is not always easy to prove if the sins are actually of one side or the other one; a expertise is usually carried out by a technician to establish the liability of the parties.