Don’t Destroy your Home with Insulation and NO Ventilation
Summary
30/09/2009
Archicentre News Release
30
September 2009
Don't
Destroy your Home with Insulation and NO Ventilation ….Mould can result in black specks
on the wall, pungent odours and toxic air which can cause respiratory problems,
especially for asthma sufferers.
People turning
their homes green by taking action to seal them to stop heat escaping and cut
power use have been warned to balance their activities with sensible ventilation
or risk expensive repairs by Archicentre, the building advisory service of the
Australian Institute of Architects.
Insulation ready to be intalled in a property.
Angus
Kell, ACT & NSW State Manager of Archicentre said energy-efficient strategies
without ventilation can cause homes to suffer extreme condensation resulting
in rotting plasterboard and timber and the introduction of mould and fungi.
"With
the recent change in weather patterns and heavy rains in many parts of
Australia, leaking roofs, guttering or downpipes that could allow water
to leak into the ceilings or walls of homes with insulation could result
in mould and fungi.
"If the
home owner is away on holidays or the house is locked up for some time
without circulating air the dampness and resulting mould can result in
black specks on the wall, pungent odours and toxic air which cause respiratory
problems, especially for asthma sufferers."
Mr Kell
said the Federal Government's insulation strategy could spark a national
flood of complaints unless insulation installers had ensured adequate
ventilation in the roof cavity.
"Even
worse is if the insulation became 'wet' through condensation it would
need to be removed making the Federal Government's subsidy in such cases
worthless."
Archicentre's
national pre-purchase home statistics show on average 30% of all houses for
sale have a leaky roof providing an opportunity for the insulation to become
damp or waterlogged if the leak is bad.
2009
National Statistics on Building Faults from Archicentre Inspections
VIC
QLD
WA
NSW
SA
TAS
Roofing
53%
31%
30%
37%
37%
40%
Rising damp
32%
32%
30%
47%
46%
25%
Causes of
falling dampness
Water pipes, stormwater pipes, roofs, gutters and downpipes can all leak water
into roofs, down walls and also into the ground which will also increase the
chance of rising damp. A thorough examination of all these elements may reveal
sources of leaks. Minor guttering problems can be patched with bituminous tape
or similar. Water pipe problems and other persistent problems may be solved
through reference to Archicentre's Technical Sheet on 'Roofing and Guttering'
at http://www.archicentre.com.au/RoofGutter08.pdf
or by contacting a licensed plumber for major repairs.
Water from
leaking roofs or condensation on the underside of roof sheeting can travel for
some distance before it finally appears within the house as falling dampness
making it difficult to determine the precise source of the problem. Tracing
the origin of white salts on the underside of the sheets or tiles may produce
the answer. Replacing the roof sheeting or tiles, patching partly defective
surfaces or reducing condensation where possible are the best solutions.
In houses
built without eaves, with the gutter fascia often in direct contact with the
wall, the slightest irregularity in gutter placement or blocked or damaged gutters
may result in water overflowing directly down the wall, increasing the likelihood
of water penetrating behind loose render. Particular care must also be taken
with the location and correct plumbing connections of rain water tanks and air
conditioning condensate drains located against walls to avoid similar potential
problems.
Causes of
condensation dampness
Cold surfaces within the house on which condensation takes place are typically
ceilings or windows, the tops of walls or in stagnant areas e.g behind cupboards.
Also the underside of the roof-covering can easily become cold enough to be
the location for condensation, particularly with metal roofs.
The origin
of moist air can simply be the house occupants, but the common sources of large
volumes of water vapour are cooking, bathing or clothes drying.
The cure
for condensation dampness
Simple cases of condensation dampness on ceilings and the top parts of external
walls can often be ended by installing ceiling insulation. It stops both the
ceiling and the tops of walls from getting too cold and brings with it a significant
saving in the amount of fuel needed to heat the house in winter.
Heavy drapes with pelmets over windows similarly create an insulating layer
of air, preventing condensation on the colder surface of the glass.
In addition increase airflow through the house at times when the external air
is drier, thus decreasing humidity. This could involve opening windows and cutting
back shrubbery.
All exhaust flues from cooking, bathing and clothes drying should be vented
externally and not into the roofspace where they can cause condensation problems
particularly when the house has a metal roof and ceiling insulation.
Media Enquiries:
Angus Kell,
ACT & NSW State Manager Archicentre (02) 9411 1000 Mobile: 0412 565
023 Ron
Smith Corporate Media Communications Archicentre (03) 9818 5700 Mobile: 0417
329 201
Insulation ready to be intalled in a property.