Combating dampness
A damp home is hard to heat and can make you and your
children sick. Damp homes are associated with increased numbers of
doctor’s visits for respiratory problems such as asthma.
Dampness encourages mould and mildew which can also harm your
health. Damp homes also deteriorate more quickly, and they’re
uncomfortable to live in.
There are three ways to combat persistent damp in your home: insulate, ventilate and heat.
If you are certain that the dampness is not caused by leaks brought
about by weathertightness problems (roof, claddings, around windows,
doors or deck areas)then follow the measures described below.
How do I know if my home is damp?
Signs of high levels of internal moisture are:
- Condensation on
hard surfaces
- Swelling and
rotting wood or wood-based materials.
- Bubbling wall
linings and vinyl floor coverings.
A damp home may have only some of these signs or many.
Mould
Mould is known to cause inflammation, allergies and
infections.
It is a relatively straightforward process to remove mould
from hard non-porous surfaces such as glass or ceramic tile. Removing mould
from porous substances such as wallboard, wood and carpets is more difficult
and more hazardous. This is because spores can be released when disturbing
rotten material and these can cause inflammation, allergies and infections.
New Homes
In new buildings, some moisture is trapped during the
construction process. Wet timber may also have been used. This will dry out
eventually over the first year of the building’s life, as long as the house is
properly heated, ventilated and insulated.
Under the floor
To prevent damp air from building up under the floor:
* Make sure there
is sufficient ventilation
* Make sure water
isn’t draining from paths or gardens under the house. You may need to create
channels or underground drains to divert surface run-off.
To prevent damp air from being drawn into your home through
the floor:
* Cover the ground
area beneath your home with heavy-grade polythene, taped at the joins and
trimmed neatly against the foundation walls.
* Look at
insulating beneath the floor.
Condensation
Showers, cooking, especially on the stovetop, flueless gas
heaters, and indoor drying of clothes all create large amounts of water vapour
leading to condensation.
The best remedies are to reduce the amount of moisture or
extract moisture as close to its source as possible. Some good ways to reduce
condensation include:
* Not drying
clothes indoors.
* Putting lids on
pans when cooking.
* Using extractor
fans when cooking or showering.
* Keeping your
showers short.
* Cover fish
tanks.
* Choosing
household plants that don’t require a lot of water – for example, yuccas,
succulents and dracaenas.
Ventilating
Let moist air out and dry air in by:
* Opening your
windows – especially in wet areas such as bathrooms and kitchens. Even in
winter on dry days it’s worth opening windows to let the house dry out. You
will have to heat the drier outdoor air but it will be easier to heat than the
moist indoor air.
* Closing doors to
contain steam/condensation in wet areas.
* Using extractor
fans in bathrooms and kitchens (but never vent them into the roofspace above
the ceiling or under the floor. Always vent them outside).
* Venting clothes
dryers to the outside (an average load creates 5 litres of water vapour).
* Installing vents
into aluminium windows.
* Using a
dehumidifier or forced ventilation system – however, forced ventilation systems
can be expensive to install and dehumidifiers can be costly to run. Try to
address the cause of the moisture build up instead.
Insulating
* Block off
draughts.
* Insulate your
ceiling.
* Consider
installing double or secondary glazing.
* Check that
existing insulation is in good condition. As a guide, insulation should fill up
to the top of the roof/ceiling joists.
* Insulate beneath
the floor. The floor accounts for 10% of heat loss.
* Well-fitted
heavy curtains, drawn on winter nights, will help retain heat gained from the
sun during the day.
Heating
* Aim to keep the
indoor temperature at least 7ºC warmer than the outdoor temperature to prevent
condensation forming on colder surfaces. The World Health Organisation
recommends an indoor temperature of at least 16 ºC.
* Use low levels
of heat all the time rather than high levels in short bursts. This reduces
condensation.
* Avoid flueless
gas or kerosene heaters – they release up to one litre of water per hour.
* In damp
cupboards, consider installing a cupboard heater, especially if it has an
external wall.
Source
Consumer build
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