Not all mould is created equal Finding it in your home not always a cause for al

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Not all mould is created equal

Finding it in your home not always a cause for alarm

Vancouver Sun - British Columbia, Canada*

Joanne Hatherly, Canwest News Service

Published: Friday, April 18, 2008

http://www.canada.com/vancouversun/news/at_home/story.html?

id=f49159a2-5426-487a-8b0a-ecf031a6ba7a & p=1

Growing mould in a Petri dish for science class is fun; growing

mould in your home is not. Mould in the news triggers alarm, but it

need not be so, says Rutten, a building science specialist at

B.C.'s Chatwin Engineering and owner of air quality auditing firm

Enmedex.

Mould in the right place is a good thing. Outdoors, it helps break

down and digest organic material such as dead leaves.

Mould indoors, however, has been implicated in a variety of symptoms

in people who are sensitive to this allergen. Symptoms include cold

symptoms, headaches, difficulty breathing, skin irritation, allergic

reactions and aggravated asthma symptoms. Pregnant women, infants,

the elderly, those with respiratory problems or weakened immune

systems are more susceptible to mould.

Lance Jakubec, senior researcher at Canada Mortgage and Housing

Corporation in Vancouver, says the reaction to mould is highly

individualized.

" You can have two people living in the exact same mould conditions

and one will be flat on his back exhausted, and the other is fine, "

Jakubec says.

When non-specific symptoms emerge, mould is often fingered as the

culprit, but Rutten notes that other common allergens also lurk

inside homes. A house that has mould growth is a damp house, and

that dampness can attract other biological and non-biological

contaminants such as dust mites and rodents.

The U.S. Environmental Protection Agency reports that damp buildings

can also cause building components or furnishings to break down and

release chemicals into the air.

How do you know when mould is a problem?

Smudges of mould in window sills or shower stalls only require a

wipe with a household cleaner and water. Bleach destroys mould

immediately, says Jakubec, however some prefer to use regular soap

products because they find bleach fumes irritating.

" Mould can't grow on glass, vinyl or aluminum, " Rutten says. " When

you see it on your window sill, it's growing on a film of dust,

especially in homes because where you cook, there are oil films

being deposited on surfaces. "

" It's the mould you can't see that's a big problem, " Jakubec says.

Mould growing through the drywall, or watermarks forming anywhere

inside is often the tip of the iceberg. That kind of mould warrants

a full-scale investigation to locate the source of the problem

inside the walls, crawl space or attic.

If condensation regularly forms on your windows or walls, odds are

that your home has humidity levels exceeding 60 per cent, and that

can promote mould growth.

" It's not a problem if it happens occasionally, " Rutten notes, " but

if it's consistent, you need to look at it. " When more people occupy

a house, or where there's more cooking, more moisture is released

into the air and that can temporarily raise humidity levels.

Good housekeeping and proper ventilation are key tools in repressing

mould.

A house should have a third of its air exchanged every day. If you

wake up in the morning to a house still filled with the aroma of

whatever you cooked for supper, then it's likely your house needs

more ventilation.

Mould isn't an old-house syndrome. Homes built up to the 1960s were

well-ventilated and rarely have mould issues. The majority of homes

with mould problems were built in the 1970s, when houses

were " tightened up " to conserve energy.

Moisture problems are often caused by leaks in the home, either

through the roofing, plumbing, improperly sealed chimneys, windows

and doors, or as a result of floods. Resolving the leak usually

solves the problem, however, the longer moisture has been present,

the more extensive the damage, Jakubec says.

Bill Okell, owner of Okell Waterproofing, is a contractor

specializing in detecting and repairing moisture in homes. He says

moisture sources are often a single point of entry, or related to a

single architectural detail that repeats in the home, such as

windows and flashing junctures.

" The fix is often less expensive than people expect, " Okell

says, " and related to a small part of the house. That's been my

experience. "

TRACKING DOWN MOULD

- More than 270 species of mould are found in Canadian homes.

- Mould spores appear everywhere, but they need moisture and

nutrients to grow.

- High moisture levels in the home can come from leaks through the

floor, walls, roof or plumbing; moisture is produced from everyday

activities such as bathing, washing clothes, cooking. Moisture also

builds up when homes are not properly ventilated.

- Mould can be black, white, red, orange, yellow, blue or violet.

This may make it sound like it is difficult to identify, but if it

loses its colour or disappears when dabbed with a drop of bleach, it

might be mould.

- Not all discoloration is due to mould; some comes from cigarette

smoke, burning candles indoors and fireplace soot.

AVOIDING MOULD

- Front-loading high-efficiency washers can get mouldy if not

regularly cleaned. Add a cup of bleach or vinegar to an empty hot-

water wash cycle. Wipe out the rubber seals around the door-opening

where water can gather with a vinegar-soaked cloth. Check the small

drain holes in the seals aren't plugged with dirt or lint, thus

preventing water from properly draining from the seal.

- Keep it clean: Old-fashioned housekeeping is the first line of

defence against mould. There are no strict guidelines for how often

to give your home a good scrub, but people who are more sensitive to

allergens should clean more often, perhaps on a weekly basis, while

others might be able to go two weeks between rigorous cleaning.

- Declutter: Don't store boxes up against concrete walls or floors,

which can leach moisture into the boxes and create a haven for mould

while damaging your goods.

- Carpets laid over concrete slabs without a vapour barrier or

ventilation can absorb moisture from the concrete. Carpet nails that

turn rusty indicate moisture is leaching up from the concrete or

from some other source.

- White salt marks forming on concrete might indicate that excessive

moisture is moving through the foundation. Get your weeping tiles

checked by a professional.

Finding it in your home not always a cause for alarm

- If you think you have a mould problem, but aren't sure, building

science specialists can assess your home's air quality and check for

mould. Prices vary, but most residential mould assessments are

priced in the low hundreds. CMHC's Jakubec notes that coastal areas

have more mould problems than other parts of Canada, but the types

of mould remain the same.

- You can get that mould tested to find out what type it is, but

more often your money is better spent on just getting rid of the

mould, " Jakubec says.

- To learn more about mould, a good resource for science-based

information is the Canada Mortgage and Housing Corporation. Check

its website, www.cmhc.ca or call for brochures on mould. 1-800-309-

3388.