MOULD CONTROL PT
How Mould forms
- When moist warm air meets a cold surface like a wall or window and is at or below the dew point temperature, dew (condensation) will form, that then leads to mould growth
- Years ago our homes had draughty windows & doors, gaps in floorboards with a fireplace drawing air in and up through the chimney, creating constant air changes within the home, clearing moisture and condensation
- We now have double glazed windows and doors, silicone sealants, insulation, no open fireplace, all preventing air changes and circulation.
- Mould thrives on moisture / humidity and feeds on organic materials – wood, fabrics, dust etc.
- Combine these and mould spores in the air will settle and start to grow
- Obvious signs of mould are discoloured spots / patches on walls, ceilings, window reveals, causing, blistering paint, peeling paper ‘blown’ plaster/render with a persistent musky odour that lingers in the air.
How does mould survive inside your home?
Mould spores are everywhere and needs a food source and moisture to grow, unfortunately, houses offer an ample food supply, where these conditions are present.
Spores can germinate after only 12 hours in some conditions, some grow in 24 to 48 hours.
When materials become damp, settled spores can become growing moulds and potentially toxic.
When surface mould is disturbed, mould spores become airborne and can enter the human body through inhalation and touch.
Mould and mycotoxin exposure impact and possible symptoms:
Although symptoms can vary, the most common symptoms
seen in people exposed to mould indoors include:
- Nasal and sinus congestion.
- Eye irritation, such as itchy, red, watery eyes.
- Wheezing and difficulty breathing.
- Cough.
- Throat irritation.
- Skin irritation, such as a rash.
- Headache.
- People with mould allergies may have more severe reactions.
When we breathe, we also breathe the dust particles that are in the air. The more activity there is in a room, the more the dust swirls up and moves around in the air. Dust particles can contain harmful chemicals that evaporate from various consumer products such as furniture and cleaning products. The particles are deposited in the lungs and can be absorbed into the body.
Frequent cleaning is the best weapon against mould spores and dust and thereby reduce allergy symptoms and the harmful effects of the substances and chemicals that accumulate in the dust. Remember to ‘air out’ during cleaning, and make sure to reduce the use of hazardous chemicals. Dust mites absorb moisture through the skin, which means that they dry out and die if the humidity is kept down, therefore airing out and using a dehumidifier is sometimes. necessary
Air Test (ERMI)
Home Air Test (DIY)
Air Test (ERMI)
The Environmental Relative Mouldiness Index (ERMI) Analyses the mould DNA in dust samples Using a vacuum or swab, collected from surfaces like carpets, wardrobe top. EMRI tests are shipped to you and normally provided with the required return postage. your report will then be emailed to you within 3-4 days with the results and a list of the different types of moulds identified.
Home Air Test (DIY)
A mould air sample testing kit can be purchased to test in your home yourself. By Leaving a small petri dish out in an enclosed room for 24-48 hours, the chemical in the petri dish will absorb mould particles from the air, put a lid on the dish and seal it. Check it after 2-4 days to see if mould has grown inside the dish.
So the main difference is that ERMI collects spores and DNA from dust, whereas air sample home test collects spores from the air.
MOULD CONTROL PT
Preventing condensation / Humidity
An average shower room can take up to 7 hours to dry!
- After a shower, use a squeegee (rubber blade) or a vacuum tool to remove excess moisture from screens, tiles, mirrors and windows etc.
- Avoid drying laundry inside, on or near radiators, use a self condensing tumble dryer, or a model that is properly vented to outside.
- Always use the extraction hood when cooking, a vented/ducted outside model (not the recirculating type!) large amounts of steam is generated using pots and pans for boiling, frying etc.
- Switch the electric kettle off when water starts to boil, automatic mode can take several seconds to terminate
- Open windows, doors twice a day for 15/20mins. Leave windows slightly open (on lock), open trickle vents (if available). Try to create a through flow of air
- All the above add up, no matter how small, and will help prevent excess moisture circulating within the home.
- Invest in a Hygrometer, a simple low-price device (5/10€) that will measure the relative humidity, which ideally should be between 45/60% RH
Removing/cleaning Mould
For lose spores/dust use a HEPA filtered vacuum, this prevents the spores becoming airborne
Spray the mould effected areas, using a mix of x2 parts white vinegar, x1 part baking soda, x1 part hot water. Leave to soak for 20 minutes (wear a mask and gloves) wipe clean using hot water, with a dash of washing up liquid
To finish, again use a spray bottle, add a quarter teaspoon of clove oil to x1 litre of water, and again spray the areas, wipe clean. Clove oil is excellent at killing the spores.
Why You Should Never Use Bleach To Clean Mould
Bleach does clean mould, but it comes with a catch. Bleach labels will warn you that chlorine bleach will only be effective on a hard, non-porous surface. This basically means that chlorine bleach is not made to soak in. Therefore, its disinfecting properties are limited to a hard surface like tile or glass. So, here’s the problem: To ensure survival, mould spores spread its roots (Mycelia) deep into a porous surface.
Mould requires a cleaner to reach deep down into the wood and other porous materials to remove or “pull out” the roots. The properties of bleach prevent it from soaking into these materials. The surface mould looks gone (it’s bleached white) but the internal mould always remains to grow back.
When bleach is applied, the chlorine quickly evaporates after use, leaving behind a lot of water. Bleach contains 90% water and mould LOVES water. This water often soaks into the porous surface allowing the mould to flourish and re-grow in this moist environment. So, in effect, using bleach actually feeds the internal mould spores! Although the surface may look bleached and clean, the remaining spores will root deeper, stronger and will often return worse than before.
Bleach is highly corrosive to skin. Exposure to bare skin creates a hydrolysis reaction. This means the “oily” feeling is actually the top layer of your skin beginning to dissolve. Bleach is not only hazardous to your health, but it will also make your mould problem worse in the long run.
Mechanical Ventilation Options
Extractor Fans
PIV Units
Single room heat recovery ventilation unit
Extractor Fans
The Intellivent Sky Bath/shower room extraction fan. Features include self adjusting humidity control, automatically increases airflow with increased humidity. A world first ‘odour’ sensor that detects strong odours and increases speed to eliminate. Low running cost, extremely quite, blue tooth equipped for easy access/control. Maximum air flow (free blowing) 140 M3 per hour.
PIV Units
A positive input ventilation (PIV) system covers an average 3/4 bedroom house. The unit can be installed in the loft area or wall mounted.
A PIV unit continuously draws in air, filtered and gently fed into the home, driving out excess moisture and condensation via a diffuser that is usually located in a central position, for example the landing or hallway area. Removing harmful traffic emission, pollen and radon etc. Nuaire pic, PIV unit
PIV units are low maintenance. Filter clean or replacement every 3-5 years. ‘Fit and forget’ sensors detect humidity levels automatically and will shut down once the ideal humidity level is reached
Single room heat recovery ventilation unit
- Designed for a single room/area
- An effective method to control humidity / condensation. Extracting ‘moist’ indoor air and allowing prewarmed dry air in. Achieving sufficient levels of ventilation automatically. Up to 93% of heat can be recovered that would normally be wasted when a traditional extractor fan is used.
- Wi-Fi data exchange available between single room units for coordinated operation providing a whole house, de centralised heat recovery solution.
MOULD CONTROL PT
Exterior: What to look for / check
- Chimney stacks: flaunching and flashings
- Tiles/slates: Check if any have slipped/cracked. Are the ridge tiles secure/water tight?
- Check rendering for any micro/hairline cracking, is the pointing to stone/brick in good, sound condition?
- Are all gutters and downpipes functioning correctly, no leaks? Grab your umbrella! Best viewed when raining!
- Check windows and doors for possible leaks. Do the window sills have sufficient overhang with an anti capillary drip, (groove line under the sill) to prevent water flowing down the wall
- Are paths, patio, earth ground levels a minimum of 150mm (6”) below the interior floor level? They should slightly slope and take water away from the property.
- Is a French drain necessary? A great solution if exterior ground levels are to high and causing ‘bridging’ or water is pooling / collecting adjacent to the property and requires drainage.
- Damaged water pipe? Fractured or broken underground pipework? Inspect for leakage.
The benefits of Lime!
Unlike cement render or Gypsum plaster, a lime render/plaster allows walls to breath, makes them permeable (we will use the word ‘breath’ to keep it simple) A concrete floor prevents moisture and damp rising, and so directed to the exterior walls. If the walls have cement-based render or plaster both inside and out, moisture and damp will travel up and inside the walls, becoming trapped and cannot escape. Damp walls equal cold walls that will then attract condensation and mould. This applies especially to solid stone or brick walls or walls that have damaged/no DPC A Lime based render/plaster will let moisture and damp evaporate and escape. Hydraulic and hydrated lime mixes are used for both insulating interior walls and protecting the exterior against severe weather conditions. Different mixes are applied to different climates and areas. This also applies to stone or brickwork, if the mortar (pointing) is cement based, not permeable, moisture cannot escape and will attack the stone or brick, eventually causing ‘spalling’ where the face of the brick or stone crumbles/flakes and deteriorate. Dry walls retain heat, similar to a storage radiator, the bricks inside remain warm for several hours, even after been turned off. Once walls are heated, they retain the heat, no need for your heating to be constantly ‘ON’ but when damp up to 40% of heat loss occurs. Lime enables absorbed and surface moisture to evaporate quickly ensuring no accumulation of moisture which can lead to the development of mould, infestation and deterioration of the building fabric.
