Who is to blame for Mould in a rented property?

Who is to blame for Mould in a rented property?

Who is to blame for Mould in a rental property?

The law is quite clear about this:

It is a legal requirement under the ‘repairing obligations’ set out in Section 11 of the Landlord and Tenant Act 1985. The Act states that the “structure and exterior of the dwelling-house” as well as “the supply of water, gas and electricity” and “heating and heating water” need to be kept in working order.

In respect of the term ‘structure’ this will mean it should be free from structural damp. This would cover Rising Damp, Bridging Damp and Penetrating damp. A rental property should be fit for purpose and free from structural damp. This is covered in section 10 of the Landlord and Tenant Act 1985 “freedom from damp”.

However, pipe leaks and Condensation damp are also forms of damp that need to be prevented and a rental property should be free of these issues. Pipe leaks are a common issue related to plumbing pipework being defective, radiator pipes and valves defective and seals around bathroom fitments defective. Condensation damp is a consequence of a lack of ventilation and heating.

Ventilation is also referenced in respect of the Landlord and tenant Act 1985 listed in section 10. However, there is very little formal guidance on what form the ventilation should take so, from our very many surveys undertaken, on the assumption the property is free from structural damp, working to the recommendations of Part F building regulations and the facilities that a local authority Environmental Office would want to see in a rental property, here are our own recommendations:

  1. All window openings to have have a security lock setting or a security lock ventilation opening device. To enable a tenant to open any window to provide a source of ventilation but remain secure in the property or that the property is secure when unoccupied but being ventilated.

  2. When and where appropriate and in accordance with building regulations, for warm air appliances to have the appropriate warm air appliance ventilator that cannot be closed.

  3. For all mositure producing rooms such as Kitchens, Bathrooms, Utility rooms, Cloakrooms, En-suite and Wetrooms to have installed mechanical extract fans with the very minimum basic feature of a run-on period after the fan is switched off.

If a rental property offers the ventilation provisions listed in 1, 2 and 3 above and that are kept in good working order, free from defect and regularly maintained, it is unlikely a Landlord will be held responsible for a complaint of Condensation damp as the bare minimum provision for ventilation will be available to a Tenant. If these provisons are available and Condensation damp develops leading to black mould growth a Tenant would be challenged on how these ventilations items are used and how often.

This said, despite having these bare minimum ventilation provisions in place, Condensation damp and black mould can still be an issue despite them being used if a property is insufficiently heated and its energy efficiency is below standard such as flat roof extensions built years ago without any or very little insulation.

In summary, if a Landlord offers a property that conforms to an appropriate energy rating standard, has an efficient and maintained heating system, offers the bare minimum ventilation provisions listed above and is free from structural damp, they will NOT be blamed for Condensation damp and black mould and no legal action would be successful against them if attempted.

We have set out the bare minimum ventilation provision to prevent blame being apportioned to a Landlord for black mould however there is also the question of what will work by way of ventilation according to the property circumstances.

For instance, taking a 2 up – 2 down mid terraced property, adding an extension to the rear and doing a very basic job of carving the rooms up to create a House of Multiple Occupancy, (HMO) and installing the very bare minimum ventilation provisions whilst might comply with regs will in all probability be insufficient for the use of the property and Condensation from the very many more appliances being used and at all possible times of day, mean a black mould problem will occur in possibly a number of rooms.

Time and again, for spending the absolute minimum on ventilation provisions to get past the very bare legal requirements, does not guarantee freedom from black mould even with the occupants using the ventilation provisions as there is a direct imbalance as what meets with building regulations and what is fit for purpose in the practicality of modern day living demands.

So where a basic £10 intermittent fan might meet regs it will simply not do the job of preventing condensation damp. It might keep a Landlord out of court but there is likely to be unhappy tenants, complaining of mould that will need to be treated. There is now a move by many Landlords to move away from basic intermittent extract fans to low energy, continual running extract fans that are far more efficient and despite being continual running, are cheaper to run than intermittent fans. Such as the superb Elta dMEV II HT


These fans can be installed to run and boost without any interaction with a tenant. Silent running in trickle mode so they do not annoy occupants in adjacent bedrooms. absolutely no need for them to be switched off and far more efficient.

Beyond this and if either a Landlord, managing agent or Tenant needs proof of the efficiency of their extrat fans, we highly recommend the Airtech SensaFan or DataFan which again, are continual running, whisper quiet, low energy fans with separate maintenance free humidity sensor data loggers that provide rolling data analysis on air quality and run time of a fan demonstrating its value in maintaining humidity at acceptable levels preventing black mould. Or, if one of these fans are installed and black mould is present, it can prove if power has been cut to the fan or the fan interfered with resulting in the black mould forming.

Demonstrated by the Airtech data logger data analysis below with image 2 showing how the humidity is well under control and air temperature well apart from dew point temperature. As a desktop excercise it could be told that black mould would not be present in this area.

In summary, if a Landlord provides basic ventilation provisions and a Tenant chooses not to use them, the Landlord cannot be blamed for black mould issues on the basis the property is free from structural damp, has an efficient heating system and is insulated to correct standards. If insufficient ventilation provisions exist or ventilation systems not maintained, a Landlord can have steps taken against them and ultimately, legal action. We recommend that for the benefit of the property and to protect the Landlords asset from damp, that better than the bare basic ventilation options are installed.

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