Black Mould Treatment and Solutions

Black mould is a common problem for many households across the UK, leading to unpleasant internal environments, damage to surfaces and furniture, and even health risks. Black mould is common in damp, humid and poorly ventilated areas and can leave black patches and stains throughout a property if not removed.

There are a number of methods for treating black mould, from DIY solutions to professional cleaning and treatments aimed at the root causes of the problem. Ultimately the treatment required will depend on the scale of the problem, necessary ventilation requirements, and thermal efficacy of a property.

Rentokil Property Care have been providing advice and specialist solutions for damp and mould problems for decades, and can provide you with professional solutions to safely eliminate mould and provide long term solutions for the root cause.

Black mould will typically occur during the colder months of the year, and you need to understand where the source of excess moisture is coming from. Sometimes black mould can occur because of plumbing issues such as leaking pipes or appliances. Penetrating damp can also cause black mould to form, as moisture penetrates through the fabric of a building, creating a cold spot where warm humid air inside the property can condense. This is more likely to occur in solid not cavity wall properties where water penetration is not prevented by the cavity. But the most common way black mould forms is from water vapour in the air condensing on cold surfaces, as it builds up within the property due to a lack of ventilation.

Everyday activities from bathing, drying clothes, washing and even breathing contribute moisture to the atmosphere, and this is called humidity. If excess water vapour is unable to escape, when it cools to dew point and lands on a cold surface it will condense as water droplets.

You must first understand the root cause of the problem to prevent it long term, as different sources of moisture may require different treatments, including improvements to ventilation and removing cold spots. While some turn to dehumidifiers to help remove the excess humidity in a property, they will not address the underlying cause of the problem. For a long term solution you may require more permanent improvements to ventilation.

A CSRT or CSTDB qualified surveyor from Rentokil Property Care can provide you with answers on why you have black mould forming in your property, and can offer advice and treatment options for a long term solution.

For minor and isolated patches of black mould, wiping them away may work. This is what many occupants will do for minor black specks around window frames in winter. If you have allergies, make sure to use gloves and a mask, while a mixture of liquid soap and water can be used to remove the mould.

The most important thing to remember is that the problem is caused because there is excessive amounts of moisture inside the home, so you must address the source of moisture causing the problem.

For many however, black mould can be a much more extensive problem, and will require efforts to reduce the amount of moisture being produced from cooking, cleaning and bathing. Ventilation may also need to be increased, by using extractor fans, opening window trickle vents or fitting a PIV unit. Black mould can not be solved by wiping away and painting over it, as this will only offer a temporary fix and will not fix the underlying issue.

Identify where the moisture might be coming from, and make efforts to remove it through ventilation, or making changes to every day activities. If the source is the kitchen, try to cook with lids on pans and a window ajar, while trying to keep doors closed when showering to prevent humid air from escaping.

While small changes to moisture production may reduce the amount of moisture in the air, improving ventilation is one of the most effective long-term solutions to prevent mould caused by condensation. This can be carried out by using extractor fans, the installation of PIV units or opening window trickle vents.

When black mould is forming on walls and ceilings, you may need thermal improvements. Black mould on ceilings could indicate missing loft insulation, while external walls can be affected by cold bridging. Thermal plastering and anti-condensation paints can be used to increase the thermal efficiency of walls, helping remove cold spots where more traditional insulation methods are not suitable.

In some cases professional mould cleaning is required for properties affected by serious black mould problems. We can provide homeowners with mould cleaning options, while they can be a valuable option for social housing providers and private landlords with housing stock with particularly serious levels of black mould.

Studies have shown that exposure to all forms of mould can cause health risks and create unpleasant indoor environments for occupants due to the low air quality within a property due to a lack of ventilation, and can lead to symptoms such as sore eyes, coughing, sneezing, difficulty breathing and in some cases trigger asthma attacks.

Black mould is a term most people use to describe what they see in their home, however not all mould is black, it can also be green, brown, red, yellow, grey or white. All can cause health issues for some susceptible people. Before cleaning can take place, a qualified surveyor will carry out an initial survey to assess the property. They will inspect the affected areas (and any hidden problem spots) to determine the extent of the mould and identify what is causing the problem.

The area is then prepared for treatment by isolating the work zone and protecting your belongings if necessary. Our technicians use professional-grade protective equipment and will carry out mould cleaning using fungicidal solutions to kill the mould. They will thoroughly clean or remove any contaminated materials, ensuring that even hard-to-reach or hidden areas of mould are dealt with.

This technical expertise guarantees a complete clean that not only removes the visible mould but also thoroughly disinfects the entire area, leaving it professionally treated and safe.

Once the black mould has been removed, we can then address the root cause of the mould growth. This can include improvements to ventilation, thermal efficiency or fixing a damp issue. It is important you understand that if the route cause of excess moisture or thermal bridging is not addressed, the mould may return after cleaning.

Legislation in the UK identifies damp and mould as a ‘category one’ hazard, while Awaab’s Law and the Social Housing (Regulation) Act was introduced after the tragic death of Awaab Ishak in December 2020 from a severe respiratory infection caused by prolonged exposure to damp and mould in his home.

This legislation highlights the risks associated with damp and mould problems in homes in the UK, and the need to deal with black mould within strict time frames.

Rentokil Property Care are able to offer a thorough and comprehensive mould treatment service, working closely with our sister company Rentokil Specialist Hygiene. Repairs for associated building defects can be carried out by DCUK, while Rentokil Property Care can provide you with damp and condensation surveys, and specialist damp proofing treatments.

Every property is different, so sometimes in order to fully understand the condensation problem affecting a property, accurate information on moisture spikes is useful to then provide effective recommendations.

Rentokil Property Care can offer indoor air monitoring devices which are used to monitor humidity and temperature as well as calculating mould risk over a period of time.

As condensation is created at different times of the day, and can vary from household to household, these devices can be used to understand the root causes of the condensation problem. The findings from these devices can be used to further understand the problem affecting the property and this evidence can be used to provide recommendations.

We provide help to homeowners, social housing providers and commercial clients across the country providing solutions for condensation and black mould issues.

Starting with a damp survey, Rentokil Property Care will be able to provide you with the peace of mind that comes with professional help. Our CSRT and CSTDB qualified surveyors will take the time to thoroughly investigate your property, while using a range of methods and specialist tools to identify the root cause of the problem.

This will include the use of thermal imaging cameras to identify cold spots, whilst checking the ventilation requirements, and will provide you with guidance to effectively control excessive moisture. All findings will be detailed in an easy to read survey report, along with recommendations for treatments where necessary. This may include professional mould cleans, thermal improvements to walls, increased ventilation or insulation top ups.