Condensation - How to control/eliminate?

Hi All,

I am after advice from anyone that may have dealt with condensation issues in the past.

I have recently moved into a home that I have freshly renovated. Prior to the renovations there were numerous rooms with mould issues which I had a professional treat. One of the reasons for mould were poor ventilation as the previous tenants never opened windows and possibly excess moisture from leaking roof. Mould has not reappeared.

The home was built in 1981 and has no wall insulation.

In both front bedrooms of the house I have noted high levels of condensation in the mornings with the glass appearing almost wet and often the timber sills have a considerable amount of water on them.

I have tried moisture beads in the windows with no effect. Have also tried leaving window open slightly which had no effect.

I am thinking ducted heating may help to maintain temperature inside and dry the air out but don't really want to have that installed at the moment and the split system which seems to do the trick (or may be contributing to the problem?).

Has anyone dealt with similar issues before that can pass on advice on how to treat/maintain this issue?

Thanks in advance.

Dan

 

Concrete slab or floor boards?

Is the house lower than Street level?
Is it lower than backyard level?
How much lower?

Is it tiled roof with sarking? What's the moisture like up there?

You can get tools to measure the moisture, often used to detect chances of termites.

Termites is another reason you want to get this sorted, as a moist place is a 5* hotel for those little buggers

 

Ps had in the past:

Underfloor exhaust fan on permanently

Bathroom and laundry ceiling fans linked to light switch so that tenants forced to use the fan

Whirlybirds added to roof to exhaust any heat and moisture build up.

 

Thanks Dan,

The home is on concrete stumps on a sloping block. Subfloor is about 1000mm at the rear of the house and approx 400mm at the front under the bedrooms. I haven't checked the level in relation to street height but would say it is slightly lower. There are also some drainage issues as the drive way often pools in spots. Subfloor soil seems dry though.

Also in the front bedrooms I've noticed what looks like water run marks down one of the walls due to the excess moisture.

It is a concrete tiled roof without sarking. I had all the tiles re done (sprayed, tiles pointed, new gal valleys and broken tiles replaced) recently as it was in a pretty bad way.

When the mould specialst came through originally he noted high moisture levels especially in the bathrooms and laundry.

I think a few whirly birds might be a good idea also. And I'm thinking it might be worthwhile getting a professional to come check things out again to try sort it out.

 

Would agree with having an expert come out @dan_89

 

In my IPs (which I used to live in) I found 2 methods for eliminating condensation:

1) Secondary glazing (magnetite). Totally eliminated condensation and had huge acoustic/thermal benefits. Downside is cost, time to quote/order, appearance and inconvenience of having to open 2 windows to get fresh air.

2) Flyscreen. This one I don't fully understand but I had one window where the opening half was covered by a flyscreen and the fixed half wasn't. Fixed window covered in condensation, flyscreen'd window not a single drop. No. Idea.

 

Had an issue recently with it in one of my older apartments. The tenant had blocked off a wall vent in the toilet, hardly ever had windows open.

I'm just in the middle of adding a new big fan in the bathroom through a new big hole in the wall, added an extra window, plus will paint with some mould proof ceiling paint. I think that will stop it from being an issue.

Check if your split system has a 'drying' setting. where it removes condensation from the air.

The few times I inspected and the tenants were home, about 2-3 rooms would have condensation on the windows and the bathroom would be dripping. It's like they didn't use the exhaust fan in there at the time, have never seen such condensation. they also used to complain about it being cold - but the place had ample heating, gas and a brand new split system it's like they were too tight to use either.

Interesting to see what the place is like with the improvements I've made and new tenants.

 

I've had great success with Dulux Wash&Wear Kitchen/Bathroom ceiling paint - not a spot of mould came back. Obviously the source of the problem has to be treated first, but results were perfect.

 

I had some problems with moisture in a bathroom ceiling, did the above linking light to fan switch as well. Tenants may not like it in Winter...
Whirlybird was already there fortunately.

 

Thanks, have already bought the http://www.britishpaints.com.au/paint-products/product-selector/british-paints-ceiling-paint mainly for the 5 year mould free guarantee. See how it holds up.

 

We use mold magik after cleaning the walls in the main bedroom where we are renting. It kills mould, because bleach just gives them a good bath.
Can be bought online.

 

Dan I'm assuming this house is in Melbourne?

If the house has no wall insulation, is there any sarking in the roof under the tiles?

My guess is you have a non-insulated house with very cold winter air outside. Inside you have lots of warm humans breathing out water vapour all night long. When the warm moist air hits the cold walls and windows, the water vapour condenses out giving you the problem you describe.

The only way to fix now, is to dry out the inside air - you can do this with a de-humidifier or Air/Con set to warm which will also dry out the air.

Alternatively, or in addition to, the above, some sort of retrofitting of wall & ceiling insulation as well as double glazing of windows, so walls, ceilings & windows do not get cold, would also work.

 

I might give this a go too, thanks for the tip.
Is it legal in Australia or just bought online for convenience?

 

It's an australian website.

http://www.oilofcloves.com.au/index.php?main_page=index&cPath=5

 

Ah, very good, I'll check it out.
Cheers!

 

Water and white vinegar works the same for a fraction of the cost.

 

You will have to wipe the windows down each morning so the condensation doesn't cause more mould. This shouldn't be as bad when the weather warms up -

The condensation forms when there is high humidity inside your home and the single pane windows allow the cold outside air to come into contact with heated air inside your home.


_________________________________________________________

CONTROLLING CONDENSATION AND MOULD

The main ways of controlling condensation & mould are:
· Ventilation
· Heating
· Removal

VENTILATION

• Open windows and doors to ventilate the home and reduce the humidity level.
• Use mechanical ventilation (exhaust fans) that are vented to outside air, particularly in the bathroom and in the kitchen while cooking. This can eliminate much of the moisture that builds up from everyday activities; and
• Consider installing ventilation over appliances producing moisture, such as dryers, stoves, & kerosene heaters, or leave windows ajar while they are on.

HEATING

• Keep indoor moisture low. Relative humidity should be below 60% (ideally 30%-50%). Relative humidity can be measured with a humidity meter, a small, inexpensive instrument available at most hardware stores;
• Maintain low constant heat when weather is cold or wet. Continuous, even heating is better than short bursts; and
• Install heating in the bathroom such as heat globes.

REMOVING MOULD

• Eradicate mould when it occurs. It is hard to remove when it has been there a while;
• Do not dry brush the area. This could release spores into the air which can spread the mould further as well as cause an allergic reaction in some people; and
• There are several treatments for mould:
• Tea Tree Oil is effective. A 3% solution or 2 teaspoons in a spray bottle with 2 cups of water will suffice. Shake well before each use;
• Kill mould from surfaces with an 80% white fermented vinegar solution (available from supermarkets). After applying the mixture, leave for at least 20 minutes and then lightly sponge with clean water;
• Remove the mould physically. Killing, but not removing the mould may allow it to grow back; and
• Don’t use bleach. Bleach has a high pH which makes it ineffective to kill mould. It simply bleaches it, so it looks like it has disappeared.

REMEMBER: The only lasting cure for mould is to reduce the dampness / moisture!

 

Get a decent dehumidifier as well. Something with a 5+ litre capacity.

http://www.appliancesonline.com.au/dehumidifiers/

 

Unflued gas heaters produces a lot of water vapor.....

 

Lucky it is flued then, don't think I'd ever buy a place with an unflued gas heater