Mould Issues, old wiring. My options?

[Fenix]

Hello all.

I have a 120m2 Villa which is poorly insulated.

The tenants have mentioned the mould problems in the bathroom and the adjoining master bedroom.

I had mould problems before because my ex-flatmates never left the windows open in the house, which can be left open, with about a 10-15cm crack and not be lifted upwards as I have drilled holes in the window-sill and put big nails in there. But I can see the point about it being a security issue and may encourage potential thieves in the first place.

So I installed a shower dome to try and alleviate this problem but it seems not to be working, granted the shower isn't the only source of moisture.

I am considering my options. I know my wiring is old so I am worried about adding something like DVS/HRV/MoistureMaster/HealthAire etc might upset the old wiring. A sparky told me when you start to fiddle with old wiring that's when things tend to go wrong, so I am reluctant to do so. I can't really afford to re-wire the whole house at this stage. What are you opinions on this?

Should I consider investing in a state-of-the-art dehumidifier and let the tenants make use of it? (hopefully not taking it with them!)

I could also consider anti-mould paint but I am going to try and tackle the causes.

Also: Is a heat-transfer-system able to be used with an old open-fire place?

What could be the best bang for my buck and any other hints and tips appreciated, I am willing to throw down several thousand but not 5 digits in the case of a re-wire...

Regards,
Levi

[klauster]

Three things to consider; moisture of air, source of humidity and temperature. Cold objects like walls and windows are prone to condensation (e.g. crying windows) – and water not removed is the breeding ground for mould. Chilling the house down below 10 degrees Celsius in winter makes the situation worse because of low temperatures outdoors. Most dehumidifiers don’t work efficient below 15 degrees Celsius and don’t improve if the dampness comes from the ground (ground cover foil is cheap).
Everything on electrical power will be normally switched off by tenants to save on the power bill.
In the days when LL could depreciate buildings we installed solar ventilation, that drives warm air into the house without running costs and tenants cannot switch it off. That to consider would be my last step.

Old electrical wires in a damp house are not safe and as LL I would fear the risks.

[TheLiberalLeft]

Showerdomes DO work, and there's little to get wrong so I'm assuming it's installed correctly and the tenant isn't leaving the door to the shower open!

Failing that you have either a water ingress issue (roof, walls etc), but my first thought would be insulation. Get that sorted first.

Anti-mould paint is a bad idea - it's an ambulance-at-the-bottom-of-the-cliff solution, as it doesn't solve the source of the problem.

Check for mould in the ceiling space. What's the underfloor insulation like?

[lawt]

One thing that can help is to cover the ground under your house with polythene. It's comparitively cheap, but obviously not going to stop moisture generated from within the house. We got prices from an installer around $7.00 per m2.

Another cheap step that can be taken is to trim back any trees that may be blocking sun to the house - paticularly over Winter when the sun is lower to the north. Obviously won't help much by night, but may very well allow the house to dry quicker by day such that it reduces or eliminates mould growth. On this note too one of our places had spouting blocked by leaves and was flooding inside the eaves with a heavy rain and causing a lot of moisture to enter the house at that end.

We installed a heat transfer system here - albeit with an enclosed fire place and the result was awesome. There is no reason you can't do that with an open fire place. We installed it and got the sparky to wire it in - cost about $600.00 all up.

Beyond that ventilation is cheap and often practical, but of course it doesn't help keep the occupants warm.



But if you have the wiring that the insulation flakes off you're best to attend to that first - or you may find you don't need the other fixes as the whole house could get real warm and dry - for a few hours.

[Rowlocks]

Do you have an extractor fan in the bathroom?
My place used to have a bit of mold in the bathroom, the tenant said they painted it with anti mold paint and its been good ever since. I'm still going to install a extractor fan though.

[Fenix]

Thanks Klauster, ground cover foil is a great idea, I googled those exact words but didn't get much, is there any links you could point me to?

Yeah I do have a water ingress issue, which is why I'm really worried about the old wiring in the damp house thing. I'm living overseas for the next two to three years, but I am back for 5 days in mid-october so I just want to launch an assault on the roof (which is leaking), the insulation and the ventilation to keep the puppy safe in the mean-time before I can hit the electrics, which in a years time I believe I can manage.

The shower-dome doesn't sit completely flush in one section at the top of my triangle shower because of the design but the installer screwed it down pretty tight to the gap is fairly minimal. You're saying that at the end of the shower the tenants need to leave the shower door open, yes? I was sure this was the case as the installer said to do so, but probably the new tenants don't know!

I will be up in the ceiling space come the 17th of October! As for the underfloor insulation, I'm pretty sure I don't have squat. So ground cover foil will be on the list.

I've just discovered this http://joinerydev.co.nz/easy-air-ventilation, I think this is a good option for me, being somewhat cheap so I can put the extra money saved from a PPV system into fixing leaks and better insulating the house. If I install them, I cannot get double glazing later... so I could do both at the same time, is double glazing a worthwhile and economical option for insulating?

I'm having a roofer, a sparky, the easy-air ventilation people and home and smart energy solutions come around on the 17th to discuss a plan of attack. I'll be aided by my father, fortunately... as he's been around the trades for years, is a plumber and has a lot of roofing experience as well as he's a fair-dinkum handy-man too, so his opinion will be very important to me.

[Fenix]

Lawt... 600 dollars, just for the installation and the heat transfer system itself seperate? Could you break down the total costs?

I don't have an extractor fan, I only have one window in the bathroom, which as a villa raises upwards behind itself. I don't know how small they get but it seemed like it'd be too bulky. That, and I didn't want to mess with the electrics and/or put a hole in the wall.

[Fenix]

Having gone over the double glazing thread I don't think I'd be able to afford 10k just for glass... I'd much rather re-do the wiring.

[jimO]

do they have a gas heater

[lawt]

Lawt... 600 dollars, just for the installation and the heat transfer system itself seperate? Could you break down the total costs?

Hmm, perhaps I could have worded that better. $600.00 was all up cost, including purchase of the system and electrician. You can get various heat transfer systems from literally a few dollars to thousands. I opted for a unit with 1 inlet, 2 outlets and 3 fans all thermostatically controlled. Sparky was only about $120.00.

[Perry]

Most dehumidifiers don’t work efficient below 15 degrees Celsius . . .

But some do. One brand that does is Ebac. I have several.
They work well at low temperatures. There's often a few on
TradeMe as people install heat pumps or roof heat circulation
thingame whatsists.

[Fenix]

do they have a gas heater

Don't know, I live in overseas these days. What are you getting at here?

[Fenix]

Hmm, perhaps I could have worded that better. $600.00 was all up cost, including purchase of the system and electrician. You can get various heat transfer systems from literally a few dollars to thousands. I opted for a unit with 1 inlet, 2 outlets and 3 fans all thermostatically controlled. Sparky was only about $120.00.

Can you please point me in the right direction, websites, brands, suppliers etc and maybe some decent value for money options? 600-800 would be very reasonable to me. I will consult with a sparky or 4, becauseI better design a plan to re-wire the joint first.

[Fenix]

But some do. One brand that does is Ebac. I have several.
They work well at low temperatures. There's often a few on
TradeMe as people install heat pumps or roof heat circulation
thingame whatsists.

I've looked them up on trademe, what models would you recommend and should I avoid older ones?

[Perry]

Gas heaters pump out lots of mould-encouraging water vapour -
which is the likely reason JO asked the question.

There are more than a few perils with providing a dehumidifier.
Some you've already guessed at. Tenants can, ahhhh, 'adopt'
them into their family of possessions.

Then there's getting them to use it. Tenants can moan about
the electricity cost of using them, (I tested that @ $4/week!),
so wont use it; to having to empty the reservoir!

I use the older, box-like-looking ones, but so long as it's an eBac
it may not matter. I did a lot of comparisons and that brand is
aimed at the UK market, where the inside humidity is a colder
temperature winter problem, rather than summer.

The performance data I scoped was very revealing. The 'Asian
knock-offs' work well at temperatures around 30 degrees C (!!)
with a big fall off in performance as the temperature goes down.

The eBac ones I have seem to work well at lower temperatures,
which is what their specs suggested should occur. It's a nice
feeling to go into the bathroom in the morning to find that the
towels are all dry, the room has no lingering moisture odour,
AND the chill is off the room. The eBacs put out slightly warmed
air. I understand that the afore-mentioned cheap knock-offs
put out cool air - but don't quote me.