Dampness, Condensation and Mould

Damp:

It’s that time of
year landlords dread: their tenant complains about dampness in their
home and expect the landlord to do something about it, but what?

Nobody wants to live
in a damp home. It causes mould on walls, furniture, bedding and
clothes and it creates an unhealthy environment.

There are three
main causes of damp:

(1) rising damp
which emanates from the foundations up and shows itself on the lower
parts of ground floor walls , skirting, floorboards etc. and if left
unchecked can lead to wet and dry rot in floor timbers.

(2) penetrating
damp which result from faults in the structure of the building,
leaking roofs, gutters, downpipes, window frames etc. This can also
damage the fabric of the building if left unchecked and again can
result is wet and dry rot.

(3) condensation,
perhaps the most common cause of black mould and mildew on fabrics,
clothes and wallpaper.

Points one and two
are problems for the landlord to see to without delay. The landlord
is under a legal obligation to maintain the fabric of the building
which provides a safe, warm and dry home.

Condensation is
slightly different because although it can be caused by problems with
the building it is also something which may be caused by the actions
of the occupants – the tenants. That’s why it is so difficult to
deal with for landlords.

Older buildings with
limited insulation are more susceptible to condensation than modern
fully insulated buildings, but any building can be affected if the
conditions are right, even newly built ones. In fact new-builds are
often more like an air tight box, so poorly ventilated and new
plaster takes some time to fully dry out.

Condensation occurs
when moist air comes into contact with a cold surface like a wall,
window, mirror, wallpaper, clothing and fabrics etc. Warm air rises
so it is more often the tops of walls and ceilings which are
affected, usually in upstairs rooms like bathrooms and bedrooms.

The warm
moisture-holding air can’t hold the moisture when it hits cold
surfaces and it deposits tiny drops of water. When there is still
air, like the corners of rooms, behind furniture or inside wardrobes
the problem will be worse.

The usual causes are
when steam is produced from cooking, drying clothes on radiators,
baths and showers, where the steam produced is not immediate vented
to the outside.

Condensation and
black mould is unsightly and can cause health problems, so tenants
may need to be “educated” as to methods of preventing
condensation:

How to reduce
damp and condensation in the home, what the tenant can do:

(1) Produce
less moisture and make sure
it is vented to the outside.

Simple things will
make a big difference, like opening a window when cooking and
showering, keeping the doors closed to prevent moisture spread
throughout the house, keeping the lids on pans when cooking and using
cooker extractor fans, drying clothes outside (and especially not on
radiators), venting tumble dryers to the outside. Paraffin heaters or
flue-less bottled gas heaters produce a lot of excess moisture.
Landlords can help here by providing automatic ventilation fans in
kitchens and bathrooms. These come on automatically when they sense
steam / moisture.

(2) Maintain a
reasonable level of heat. A cold house leads to cold surfaces which
absorb moisture. By maintaining a good level of heating in the home
the surfaces will not absorb the moisture and therefore there will be
little on no condensation. Heating, coupled with good ventilation at
the source of the moisture will cure most cases of condensation
completely.

Invariably, in bad
cases of condensation the tenant is scrimping on heating and because
the house is so cold is reluctant to ventilate. I’ve even seen
cases where ventilation ducts and trickle vents are blocked to
prevent drafts because the house is so cold. This coupled with drying
clothes indoors and all the other sources of moisture generation
leads to a vicious circle of more cold, more moisture penetration and
more condensation.

Once this cycle is
started the fabric of the building absorbs the moisture and in
extreme cases timber, plaster and masonry are damaged permanently.
Also, once the spores are established the mould will quickly return
every time the right condition are present even when deep cleaning
has occurred.

How to reduce
damp and condensation in the home, what the landlord can do:

(1) Make sure the
building is free from external defects, rising and penetration damp.

(2) Make sure the
home is insulated to modern standards meeting the latest Energy
Efficiency Standard of E or above.

(3) Make sure the
heating system is up to standard and is reasonably efficient to run –
tenants will avoid using energy if it is costing them too much.

(4) Provide
extractor fans which are an effective way to get rid of moist air and
steam so that less condensation forms. Some very modern homes have
extractor fans which are automatic or run continuously, fitted in the
ceilings of kitchen, bath and shower rooms.

(5) Provide door
closers to keep moisture confined to where it is generated.

(6) In extreme cases
think about a fully forced ventilation system where an air pump in
the attic continually circulates the air.

(7) Provide written
information to educate tenants as to how they can minimise the
problem.

How to get rid of
black mould

If the home is
already affected by black mould after a long period of condensation
build-up, it needs to be properly cleaned with a spray containing
bleach. Wear a mask to prevent inhaling mould spores which are
dangerous to health. After the area is dry it should be sprayed with
an anti-fungal wash and allow that to dry again – follow the
manufacturer’s instructions.

You can also treat
the affected areas with mould-resistant paint, available from most
major hardware stores, but this should not be necessary if the
problem is properly cured.

Images of black and
unsightly mould in the corners of rooms are always the focus of TV
documentaries and reports on the housing conditions that tenants are
living in, and almost always the blame for this is put at the
landlord’s door. A proper understanding of condensation and mould
and its causes shows that very often it’s caused by the lifestyle
of the tenants, and its only they who can do something about it.

A typical
scenario goes like this:

“I have noticed
black patches on the wall paper, mould on my clothes in the wardrobe
and a damp musty smell throughout the house but particularly
upstairs. Landlord, what are you going to do about it, are you going
to compensate me for the damage to my clothes?

“I’ve asked a
damp specialist who tells me there’s definitely damp in here, so
it’s not just me saying this, can we get someone in to deal with
it?”

A few points to
consider if you are faced with this:

Condensation, damp
and mould is a very complex issue and it’s not always obvious what
the cause is and who should be held responsible, so you should avoid
jumping to conclusions as to whose fault it really is.

Also, it must be
born in mind that advisors on damp often have a vested interest in
finding a problem, which they can then be contracted to “cure”.

If it comes to legal
action and blame, enforcement has just as often been against the
tenant as it has against the landlord when with expert witnesses
cases have come to court.

Unless a specific
cause can be identified for the dampness such as leaking roof, walls,
gutters, drains, water pipes or rising damp, the black mould is more
often than not caused by condensation – air born water vapour.

Condensation in turn
is sometimes caused be inadequacies in the building construction,
such as poor ventilation, insulation and inadequate heating systems
and older properties are more susceptible because they generally
require more heating and suffer greater heat loss.

A full investigation
should be carried out and if necessary a temperature monitor can be
installed to check the average level of heating which should not fall
below 18 degrees minimum.

If the issue results
in a dispute it is useful if landlords have a record of the history
of the property; have previous occupants experienced the same
problem, or is this down to one tenancy?

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