Damp and Mould in rented properties – what to look out for

Many properties at one time or another will experience issues with damp or mould. As a landlord you should take special note to take steps to protect your property against damp and mould and should your property experience it, it is good to know how to remedy the problem.

Why should I care?

According to the World Health Organisation (WHO) between 10-50% of indoor environments across Europe are damp, which can cause a home to become stuffy and give a faint odour. It can also make a property feel colder, necessitating the need to heat the property more increasing heating costs.

Not only this, but those people with skin or respiratory problems, or vulnerable people such as the elderly, children, or those with suppressed immune systems can be more susceptible to asthma, respiratory infections and rhinitis.

What causes damp and mould and how can I fix it?

There are three main causes of damp and each need to be addressed differently:

  1. Rising Damp

Rising damp occurs when moisture beneath a building soaks into brickwork or concrete. It is often found in ground floors or basements. It can be caused due to a failure in the property’s damp proof course, or due to the property not having a damp proof course in the first place. If not resolved, rising damp can lead to mould so it is important that if you suspect rising damp, it is checked by an expert and appropriate action taken quickly.

If rising damp is detected, you should replace any parts of the property affected, such as skirting boards, plasterwork or flooring. If you have a damp proof course then you should get a professional to check it and fix or replace it where necessary. If one is not already in place then you do not necessarily need to install one, but if the problem reoccurs then this should be considered.

  1. Penetrating damp

Penetrating damp occurs by water entering the property from the outside. Examples can include a leak in the roof, leaking pipes, or damaged guttering. These can allow water to enter the property gradually without necessarily being detected straight away.

If penetrating damp is detected, then as well as repairing or replacing anything inside that may have been affected, the root cause of the ingress needs to be found, and the necessary repairs or replacements made. This is your responsibility as the landlord as this problem is caused by the structure of the property.

  1. Condensation

This is usually the main cause of damp and mould and is a result of excess moisture in the air allowing water droplets to form indoors. If there is no way of this moisture to escape, such as an open window or vent condensation develops and this can lead to mould, usually on cold walls and window frames.

As condensation can be a direct cause of the activity of the tenants, it can be difficult to assess if it is your responsibility for rectifying the damp caused by condensation.  However, in such scenarios both landlord and tenant can help to make things better, depending on what the cause is.

Drying washing outside, keeping windows open and heating the property properly are ways of minimising damp issues. Although you can ask your tenants to help by employing these tips, they are usually under no obligation to do so and they may find it impractical or inconvenient to do so. As a landlord it is wise to seek to install proper ventilation to help manage condensation and reduce the onus on the tenant to try and help.

Some Top Tips to help prevent mould

  • Install ventilation to prevent mould from forming in the first place
  • When mould is reported to you, make sure you employ a suitably qualified person to diagnose the problem and perform any repairs or remedial work should it be your responsibility.
  • Deal with any mould quickly and effectively. Following changes to landlord legal requirements, for tenancies commencing after 01 October 2015 you are required to respond to your tenant within 14 days if they report a problem with damp or mould.
  • Maintain your property in line with your tenancy agreement.  Check the roof, gutters and drains regularly. Why not check out our tips on cleaning out your gutters

Although we always recommend that you have comprehensive property insurance in place, since damp and mould are often viewed as a maintenance issue, you are unlikely to be covered by your buildings insurance.  Therefore you should always pay special attention to damp and mould and take any reports made to you seriously. Following the guidelines above may help you to manage damp and mould and quick action can limit any outlay that you may have to make.


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