Whirly Birds and Damp

[virgo]

Hiya

One of my tenants is complaining about damp and mould...we have installed extra exhaust fans and vent holes ...

She is suggesting a whirly bird as she closes windows during the day (she leaves early and comes back late from work....)

Qn:

a) can it be installed easily on a colour bond roof?

b) will it help to ventilate and reduce damp?

c) can be done by a handyman? Is it expensive?

d) any suggested whirly bird installers in Sydney?
tks

 

[Ace in the Hole]

Not sure if whirlybirds will extract damp air from the living areas.

Where is the damp coming from?

Another solution may be to buy them a dehumidifier, they can extract a lot of moisture.

 

[tiger97]

You have to be very careful with roof ventilation, you need vents around your eaves for them to work properly, otherwise you suck air out of your house eg. conditioned warm or cool air, which is a bad thing.

 

[handyandy]

Extra exhaust fans may have made the problem worse.

I suspect that the metal roof has not been constructed with sufficient care as to how the condensed water is shed from the underside of the metal. The metal acts as a condensation collector due to the temp variation between the outside air and the internal roof cavity conditions.

On most metal roofs they intall a insulation blanket with foil (sarking) on one side of the insulation. The foil side is away from the metal roofing so that the insulation creates a temperature barrier between the metal roof and the sarking.

http://www.bradfordinsulation.com.au/Products/Commerical/roofing-blanket/Anticon.aspx

By using exhaust fans to blow more moist warm air into the roof cavity you can make the condensation problem well and truly worse.

The times I have seen this problem the mould growing in straight lines on the ceiling following the roof joists. If you have a grid pattern of mould then it is a a result of moisture from condensation.

The whirly may help alleviate the problem by allowing the warmer moist air to escape the roof cavity before the moisture condenses on the underside of the metal roof. What are the vents holes that you have installed?

Someone who knows what they are doing can easily install the whirly birds in a metal roof


Cheers

 

[virgo]

Mould

Hiya

Funnily there is no mould (yet?) on the ceiling..tenant complains about excessive condensation on the floor tiles (porcelain), excessive condensation on the windows and sliding door and on one wall ...

Mould is appearing behind the TV cabinet and on clothes and behind sofa....

Go figure!

 

[depreciator]

Where do the exhaust fans vent to? Surely they aren't going into the roof cavity.
Is she using an unflued gas heater? They can put a lot of moisture into the air.

 

[virgo]

Hiya

She does not have a gas heater..only an reverse aircon which she does not turn on often plus a small radiant heater...

The only exhaust fan is in the bathroom and is vented to the outside via an under eave vent.

She complains that the porcelain floor tile sweat excessively...and that her bedclothes are damp?

When she comes back from work, she closes the windows and then when temperature drops, the floor starts to sweat...

No problems in the summer (nice and cool) but only in winter

She does not want a dehumidifier as it will be costly to run and she thinks it will not work as the house is too damp...

 

[depreciator]

Clothes dryer? They put a lot of moisture into the air. Is it an old house? Mine is and they get cold in winter. The 'sweating' floor is odd. A dehumidifier won't cost much to run, but a good one might cost $400. I bought one for a previous PPOR that was really damp - stream ran under it when it rained - and it worked really well.

 

[robbiejuve]

The last place I was renting at before I bought my PPOR was similar, probably worse.

After 2 years every wall in the house was spotted with mould, our clothes stunk of mould, my dark clothes spotted with mould.

We ran a dehumidifier in the bedroom whenever we weren't sleeping but didnt help much.

Asking around the main advice we got was "no ventilation under the house" apparantly needed to knock some bricks out and get some air flow happening down there, that seemed to solve mould for some people I spoke to.

Our landlord did nothing about it so we moved.

 

[The Fence]

She complains that the porcelain floor tile sweat excessively...and that her bedclothes are damp?

When she comes back from work, she closes the windows and then when temperature drops, the floor starts to sweat...

So, have you investigated these claims or are they just claims at the moment?

Time for an inspection of such happenings then sort it out.

Sometimes tenants exagerate things a little, just sayin..

I could be wrong but if it was my IP I would be there experiencing it for myself before doing anything.

 

[virgo]

Sensitive tenant

Hiya

Just to say this is an excellent tenant who always pays her rent AHEAD

She keeps the place SPOTLESS and SPARKLING like you would not believe it...

She has emailed me the mould forming behind her furniture and also a picture of her footprint on the "sweating" floor.

She seems to insist on the whirly bird thingy...so i really want to humour her...

QN : will it hurt to put this damn whirly bird thing on a colourbond roof? It can only help ventilation , no?

I have checked the cost and honestly, what she pays in rent is a pittance compared to the cost

 

[The Fence]

If you feel ok with it, and I do agree its not a sunstantial cost, and you're happy to humuor then go for it! Your call.

At least you can say you have tried and that done upon the tenants request.

However, if it does not work then further investigation is required to get to the root of the problem because it still could be unflued gas, long hot showers with no exhaust fan operating, no windows open, souther side orientation etc etc etc..plenty of causes im sure.

 

[The Fence]

Come to think of it, and someone already has regarding the sub floor situation, but can you tell us the details of the buildings foundations?

can have alot to do with this for sure, but we need to know all the facts before speculating upon any possible advice.

 

[Scott No Mates]

having the place closed all day is possibly one cause. A dehumidifier costs about $300 & costs very little to run.

Is it a brick veneer, double brick or clad house?

Are the damp courses in the correct position?

Are there other possible causes?

 

[virgo]

Mould

Hiya

The house is new (less than 1 year old) built on a slab and is brick veneer with a colourbond roof (skillion) ..the house does sit on a slight slope but has an agg line around the house with weep holes visible above the soil line.

it has a waterproof membrane which does not seem to be penetrated as it is bone dry during the day and no problem at all in summer...floor only starts to "sweat" when sun goes down now that is winter...

Tenant claims window has excessive condensation in the morning (isn't that normal with sub zero mornings in Sydney?)

 

[BMan]

i had this problem before i put an exhaust fan in the bathroom
and then i also added 2 whirlies dont have a problem anymore
whirlies are about $60 and took me half hr to put each in but someone experienced it should take bugger all. what took me the longest was trying to get them to look level
if you plan on doing it yourself get a jigsaw with a metal cutting blade and a drill (to start the circle off) and a few extra tech screws i only got 3 in my box

also i only get condensation in the morning if i run a heater

 

[depreciator]

Might as well bung a fan on the roof if it's cheap and see what it does. Make sure there are decent vents around the eaves as somebody else mentioned.
I guess it's just moist air condensing on cold surfaces. So the moisture needs to be removed from the air, or the surfaces warmed up. Are the floors in the whole house tiled?

 

[virgo]

Damp

Might as well bung a fan on the roof if it's cheap and see what it does. Make sure there are decent vents around the eaves as somebody else mentioned.
I guess it's just moist air condensing on cold surfaces. So the moisture needs to be removed from the air, or the surfaces warmed up. Are the floors in the whole house tiled?

Hi Depreciator

Tks for taking the effort to reply!

Yep, the whole house is tiled...no more porcelain tiles in future for me! i will stick to ceramic or floor boards..

The thing i cannot understand is how this whirly bird can suck the air out of the living room? is there a CEILING vent i must instal apart from the eaves vents?

Also can't understand this excessive window condensation either...it is a brand window you know

Worse case, i know the problem should be cleared up once winter is over (fingers crossed)

 

[handyandy]

Worse case, i know the problem should be cleared up once winter is over (fingers crossed)

Yes, evict the tenant.

Now that I understand the problem in more detail I believe the the whirly will do absolutely nothing to resolve your problem.

imho it's all down to the tenant not having any ventilation during the time she is home nor when she is home because it's cold. Result, all that moist air generated whilst she is home stays inside the home and accumulates. At night it emerges as condensation on colder surfaces.

Some of the obvious sources of moisture gas heater, clothes dry general cooking and of course breath. Is there a range-hood that exhaust to the outside. This would be a good idea if not in place. This could then at least extract all the moist cooking air from the house. Is there an exhaust for a cloths dry etc.

I had a complaint like this in a mid level unit (unit above and below) so no connection to the ground or roof. Only possible external source could be that there was a mains/low pressure leak in unit above or this unit. So went and had a look. Sure enough the walls were sweating. Checked for any source of water and found none so interrogated the tenant as to habits. Away all day leave all windows shut. Also leave windows shut at night as it was also winter. Unit has range-hood that exhausts outside but they don't use as they like to keep hot air in unit. Also they had a rise cooker going whilst I was there.

So plenty of sources of moisture in the unit with no chance of this moist air drying out - result moisture on the walls. (full brick)

I advised them to open the windows slightly during the day so that things could dry out naturally. Haven't heard from them again. This was some 4 years ago.

Cheers

 

[depreciator]

I'm not convinced the roof thing will do the trick, either. Might help keep the place a bit cooler in the summer, though - that could be the next complaint.
I reckon with these things there is usually more than one fix. With this condensation thing, it's shorter showers, a clothes dryer vented outside, exhaust fans vented outside etc. Rugs on the floor would keep the place a bit warmer and that will help, too. If she stopped breathing, that would also help.