Black mould in bathrooms kitchens preventing condensation in bathrooms and kitchens extractor fans to prevent mould

One of the major problems we encounter is the presence of mould in properties. There are many reasons for mould however the main cause that we find is condensation through poor ventilation.
In older properties with floor boards, open chimneys and leaky windows this is rarely an issue. However newer properties or where windows have been replaced with uPVC the risk is greatly increased.

Condensation occurs when warm humid air touches a cold surface.
Simple measures such as opening windows when cooking or after a bath or shower will greatly assist. Ensure trickle vents are open on windows and never block up air bricks. Leaving the heating on constant at a low temperature will also ensure the walls will stay slightly warmer.

When fitting a new kitchen or bathroom always ensure that extraction fans are fitted. The extraction rates are set out in Part F of Building regulations as follows

Building Regulations Part F 1995 England Wales
minimum size fan allowed ( extract Table 1 )
a - Bathroom - 15 litres / second
b - Kitchen - 60 litres / second
b - Kitchen - 30 litres / second if within cooker hood or 300mm of a hob
c - Utility Room - 30 litres / second
In rooms with no natural light it would be appropriate for the fans to be controlled
by the operation of the light switch.

One of the biggest issues we find is inadequate or poorly installed fans. Many fans installed are only designed to ventilate a small toilet however are expected to remove steam from a large bathroom.
We will able to calculate the exact extraction rates for any situation and then match a fan unit to suite. In many cases we will also fit insulated ducting. This reduces noise but also helps prevent condensation within the ducting.

If you are experiencing any issues described please do not hesitate to call we are happy to offer advice and can often eliminate condensation issues very quickly.

Fan and duct pictured left. Fan is small capacity unit. As warm air is drawn into duct it condensates and over a short period of time fills up with water. This is a major health hazard and a breeding ground for Legionella pneumophila.
Simple test to see if ducts are blocked is to hold a piece if tissue against the fan. If it sticks you know air is being extracted. Regularly inspect the ducting in the loft. The example shown was heavy and full of black water.
We have replaced the fan unit with a model four times as powerful and installed an insulated duct. Also fitted to the fan is a humidity stat. This starts the fan whenever the room moisture builds up.