In Britain, condensation and mould in residential property is very common, particularly where warm moist air is generated in areas like kitchens and bathrooms and then penetrates to colder parts of the building. When the air gets cold, it cannot hold on to all the extra moisture produced by everyday activities, so some of this moisture appears as small droplets of water – most noticeable on windows, or where there is little movement of air. If not properly dealt with, this extra ‘dampness’ can lead to mould growth on walls, furniture, window frames and even clothes.
Mould spores need a moist environment in which to germinate, so many mould problems are caused by poor building maintenance and lack of ventilation, such as water leaking through windows or roofs; rising damp, which is often caused by breached, missing or damaged damp proof membranes; steam and condensation from showers, bathrooms, cooking or high air humidity; and inadequate ventilation or heating throughout the home.
Pat Barber, Chair of the AIIC comments: “Damp problems can be caused by a range of factors such as prolonged leaks, dripping overflows and broken down pipes and guttering, problems with pointing to brickwork, roof problems or insufficient or blocked damp courses. Resulting mould and water staining to the interior of the property can also be caused by excessive condensation, caused by tenants’ living conditions. When activities occur that are in excess of normal living conditions, mould will appear in a very short space of time.
When a tenant moves out, landlords and agents often find that the property is afflicted with mould and it will inevitably mean expense to put things right – either from the landlord’s pocket or from the tenant’s deposit. The trick is to decide the fair course of action to take for both parties.
Internal causes of condensation for which the tenant can be liable for charges include not using extractor fans where fitted; using tumble driers without venting, which is a major cause of mould growth in a property. If no vent hose is supplied, the tenant is expected to
open windows to allow the moisture to dissipate safely. Another major cause of mould is drying wet washing on heaters and radiators - tell-tale signs of this is water staining and some bubbling to the paint on the walls behind heaters, or actual staining to the heating appliance itself. A common problem is purple or blue staining, which tells us that the tenant has been drying their jeans regularly on a heater!
Often a leak will cause mould and damp. At one recent check-out, we discovered that the kitchen ceiling had fallen down the night before. The tenants admitted that there had been a leak for weeks from the bathroom above and knowing they were moving out, they had ignored it, thinking that it would soon be someone else’s problem. Unfortunately, tenant negligence meant that whilst the landlord was responsible for repairing the leak, the tenants had to pay for repairing the ceiling.”
AIIC has put together a checklist for landlords and agents to help reduce mould and condensation in rental property:
Windows: Old style wooden framed windows allow the property to breath – but are usually quite draughty which is why, unless the property is a listed building, more often than not these will have been replaced with more modern UPVC framed double glazed windows. Whilst these are easy maintenance for landlords and help keep heat in, they are also prone to hermetically sealing a property. Tenants need to be made aware of the vents at the top of the frames and that they can lock the windows in the vent position.
Extractor fans or air vents: These should be fitted in kitchens and bathrooms. A good quick way to check the suction/extraction efficiency of bathroom and kitchen extractors is to hold something like a credit card underneath, close to the grill. If the fan has enough suction to hold the card against the vent, then it is efficient enough to extract moist air at normal living levels.
External problems: Sometimes a quick inspection of the exterior of the building will give clues as to how mould growth has appeared on the interior of a room. There could be a long standing leak from guttering, or an overflow pipe. The damp course at the base of the brickwork could have been accidentally covered by earth or gravel, which will not allow the building to ‘breathe’.
Dehumidifiers: If a property is prone to condensation, then daily use of a dehumidifier unit can be very beneficial. These come in all shapes and sizes, are widely available and cost very little to run. They draw out the excess moisture from the air helping to keep the condensation under control and can be safely left on while a property is empty. These units have tanks to hold the water that is drawn in and when the tank is full they cut off automatically, so they can be safely left on while the tenant is away from the property.
