Keep your home free from damp and mould

There are different types of dampness that might affect your home. The biggest cause of damp and mould growth in the home is condensation.

This information will help you:

identify condensation
to help treat and prevent mould growth

The Environmental Health team has a duty to investigate houses which are in poor condition and take action where necessary. If you live in a rented house or flat, see how to report a problem with your housing conditions.

Types of dampness

There are 4 types of dampness that can affect your home.

You need to know what type of damp you have so that you can take the right steps to deal with it.

Rising damp is caused when moisture from the ground rises into the home. The damp proof course (DPC) may be broken, or your home may not have a DPC.

A DPC is a horizontal membrane built into the walls of a house at low level. Older houses built before 1875 were not built with a DPC.

In newer houses the DPC can become ‘bridged’ by soil against the outside of the walls that has been built up to a level higher than the DPC. Sometimes a DPC can fail and need repair.

Rising damp only affects:

basements
cellars
ground floor rooms

It will rise to between 30cm to 60 cm up the wall and leaves a brown ‘tide’ mark caused by salts from the ground. Rising damp can happen at all times of year but is normally more noticeable in the winter.

You'll not normally see black mould growth with rising damp because the salts in the moisture prevent it growing.

Penetrating damp is caused by water passing through the external walls or roof of a house due to a problem with the repair of the building.

It could be caused by:

missing roof tiles
damaged pointing to brickwork
cracked render

It is only found on external walls and sometimes on ceilings if there is damage to the roof.

Penetrating damp is most noticeable after heavy rainfall or snow. You will see an area or patch of damp that feels and looks wet.

Leaks from water and waste pipes in the home are common, especially from bathrooms and kitchens. This damp will occur all of the time whatever the outside weather conditions.

Look at the pipework that serves your kitchen and bathroom to try and find the source of a leak.

If you share a wall with your neighbour, check with them. The leak could be coming from their plumbing within the shared wall.

You'll see an area or patch of damp that feels and looks wet. You will not normally see black mould growth with damp from faulty plumbing because the chemicals in the water prevent it growing.

Condensation is the biggest cause of damp in houses. It is caused when water droplets in warm moist air come into contact with a colder surface like an outside wall or a window.

As the warmer air hits the colder surface water drops are formed which can soak into woodwork, paintwork and wallpaper. Over time mould growth can appear on these surfaces.

Condensation occurs mainly in the winter months and is normally seen in the corners of rooms and on or near windows. It is often found on walls behind furniture where air cannot easily circulate.

Condensation and mould growth is often caused by the way we live in our houses. It can be reduced by changing some of the things we do every day that produce moisture. Cooking, washing and even breathing – all of these things put moisture into the air.

The amount of condensation in a house depends on:

how much moisture is put into the air by the occupier
how warm or cold the house is
how much air circulation (ventilation) there is

To reduce condensation, you must look at all 3 of these things together.

Common daily activities that produce moisture

Our daily activities add moisture to the air in our homes, in fact even breathing adds moisture to the air. The chart below gives some examples.

Activity	Pints of moisture released into the air
a bath or shower	2
washing the dishes	2
2 people in the home for 16 hours	3
using a bottled gas heater for 8 hours	4
cooking and using a kettle	6
drying clothes indoors	9

Reduce condensation and black mould growth

1. Produce less moisture

There are lots of things you can do to reduce the amount of moisture in your home.

Drying clothing:

dry clothes outside if possible
if you have to dry clothes inside do it in the bathroom. Open a window slightly or put the extraction fan on while you're drying your clothes, and keep the door between the bathroom and the rest of the house closed
vent tumble dryers to the outside or use a condensing type

Cooking:

cover pans when cooking and open the kitchen window slightly
do not leave kettles boiling

Heating:

do not use paraffin or bottled gas heaters. They produce lots of moisture as well as being expensive to run

2. Remove excess moisture

Wipe the windows and sills in your house every morning with a dry cloth to remove any condensation.

This is particularly important in the:

bedroom
bathroom
kitchen

Just opening a window will not be enough to get rid of the moisture on its own.

3. Ventilate

Ventilation helps reduce condensation by:

letting warm moist air escape
allowing cooler drier air into the home

You can ventilate your house without making it colder by opening windows slightly or using the trickle vents fitted to new UPVC windows.

To help ventilation:

when using the bathroom or kitchen, open a window to allow ventilation and shut the doors between the rest of the house
leave a window open for a short time after a bath or shower and after cooking and keep the door closed
open the bedroom window for up to an hour when you get up in the morning and throw back duvets to air the bed and bedding
keep windowsills clear so that you can wipe them dry easily
leave a gap between the wall and any furniture to allow air to circulate
consider fitting old chimneys or flues with air vents to allow air to circulate
make sure you have enough ventilation to meet requirements for gas appliances in a room

4. Keep your home a little warmer

When the weather is cold the best way to keep rooms warm and reduce condensation is to run your heating at a constant low background level. This is more effective than turning your heating on just when you're at home.

You can control your heating and manage costs by:

using timers and thermostats
fitting heating controllers on radiators

These organisations provide free advice on managing heating costs:

Energy Saving Trust

This is a non-profit organisation that provides free impartial advice.

It can help you to:

save money
fight climate change by reducing carbon dioxide emissions from your home

For advice and information:

Tel: 0300 123 1234

Visit: Energy savings trust website.

Better Housing, Better Health

Better Housing, Better Health (previously called the Affordable Warmth Helpline) helps Buckinghamshire residents keep warm and well at home and improve the energy efficiency of their homes.

If you are struggling to heat your home or meet the spiralling cost of domestic fuel bills you can call for free, impartial advice on:

national and local government grants
loft and cavity wall insulation including the various grants available
switching energy suppliers to make sure you are getting the best deal
fuel debt
who to contact for a benefits assessment
home improvement agencies for vulnerable homeowners
support organisations in your area
energy efficiency to keep bills down

Visit: Better Housing, Better Health website

Call 0800 107 0044

Buckinghamshire Council also offers guidance for saving energy and tackling climate change at home and in other buildings.

5. Insulate your home

Insulating your home helps to keep it warm and to reduce the cost of heating bills.

You can consider:

insulating the loft to a depth of 270mm
installing secondary glazing or double-glazing to windows
improving cavity wall insulation

For advice:

Visit: Better Housing, Better Health website

Call 0800 107 0044

6. Remove black mould

Mould spores are all around us both inside and outside of the home but because they are so small we do not normally see them. The mould spores become noticeable when they start to grow and multiply on surfaces. Mould spores thrive in the damp environment caused by condensation.

Mould growth can appear on walls, ceilings, furniture and even toys and clothes.

To kill or remove the mould:

remove as much of the mould as possible with a damp cloth, then throw the cloth away - or use a vacuum cleaner and then empty it
wipe affected areas with a fungicidal wash or diluted bleach (use gloves and safety glasses to protect your skin and eyes)
use tea tree oil (a natural disinfectant) to soak mildewed items or target trouble spots. Use 3-4 drops in 2 litres of water. Wipe, then rinse off. Always test a small area of the surface or fabric first before you use it.
after treating walls and ceilings redecorate using a fungicidal paint or wallpaper paste - do not use ordinary paint
dry clean any mildewed clothes and shampoo carpets

Getting rid of condensation and mould growth is not easy. If you only do one or two of these things it may not solve the problem.

Try to do as many as possible every day so that they become part of your normal daily routine

Contact the environmental health team

Email: [email protected]