Damp / Black Mold On Walls

buzzard

Hi there,

Looking for advice on the problem I have with Black Mould spots in my apartment. The apt is only 2.5yrs old and the front two rooms are covered with black mould on the wall to my neighbour's side and the front of the facade. Both internal walls are finished in concrete plaster and have a cold feel to them. One room is not vented however the windows are and the outside finish is plaster while the other room is vented and has a red brick finish. Both rooms are ajoining each other.

I have contacted the builder and he said that I am drying damp clothes in the room but I am not.

The question I have is what can be causing this and is there any paint that can minimise the mould ?

gizmo555

buzzard wrote: »

Hi there,

Looking for advice on the problem I have with Black Mould spots in my apartment. The apt is only 2.5yrs old and the front two rooms are covered with black mould on the wall to my neighbour's side and the front of the facade. Both internal walls are finished in concrete plaster and have a cold feel to them. One room is not vented however the windows are and the outside finish is plaster while the other room is vented and has a red brick finish. Both rooms are ajoining each other.

I have contacted the builder and he said that I am drying damp clothes in the room but I am not.

I have had a similar problem in two apartments. I had it thoroughly investigated and both times it was down to poor ventilation and resulting excessive condensation. It is unfortunately an extremely common problem in modern apartments.

buzzard wrote: »

The question I have is what can be causing this and is there any paint that can minimise the mould ?

Steracryl

http://www.crowntrade.co.uk/Products/Pages/SteracrylAnti-Mould.aspx

mad m

You probably have trickle vents in windows, do you have blinds/roller blinds put up on windows? This can block the flow of air through trickle vents. I really don't rate those trickle vents in windows...

buzzard

mad m wrote: »

You probably have trickle vents in windows, do you have blinds/roller blinds put up on windows? This can block the flow of air through trickle vents. I really don't rate those trickle vents in windows...

Yes, I have roller blinds and the trickle vents on the windows but even though I leave the windows open majority of the time the mold still returns.

Is the builder still liable for this poor ventilation as it is down to the desgin of the building or is it my problem to sort out ?

What about the mgt company's role in this ?

Thanks for you help

mad m

You haven't a hope getting anything from builder. Management company is only responsible for outside of building. This is probably the most common problem that is happening today.

Buildings are getting more airtight with pvc windows and double glazing and those bloody trickle vents are crap to be honest. You have a cold bridge on outside walls which is causing the build up of condensation, plus I would put in a 4inch air vent to try and have a constant flow of air.

The only other option is to put anti-condensation paint on walls. This can be bought in MRCB near Thomas st or Crown paints do their type. You can get it tinted in a colour.

As I said most window systems have trickel vents and people get blinds put up which will stop the flow of air.

JamesM

A dehumidifier can be got for less than €200 and works well in many cases.
Jim.

doolox

As mentioned here this mould is caused by lack of ventilation and a cold uninsulated wall which should be drylined and insulated for maximum comfort and least hassle in the long term.

If you are redecorating the wall you can try washing down the surface with a strong bleach solution to get rid of and kill the mould. The wall should then be primed with undercoat paint ( usually used for wood ) and let dry thoroughly a few coats can be tried to really seal off the wall. Then paint with any colour you like.

A painter friend used to use aluminium paint to prime the walls before finishing in two coats of emulsion paint. He said this improved adhesion and avoided peeling paint later on.

slimjimmc

I agree with doolox, a strong bleach solution (1 part bleach to 4 parts water) should clear the mould off the walls for now.

mad m

slimjimmc wrote: »

I agree with doolox, a strong bleach solution (1 part bleach to 4 parts water) should clear the mould off the walls for now.

This is only a temporary solution...As far as putting Aluminium primer on walls, its madness. Aluminium primer is for hardwood doors and not walls. Don't finish any walls that are prone to condensation is an oil based gloss finish as it will only promote it.

As was suggested get the right paint for the right job. Also the suggestion of getting a dehumidifyier is a good idea also..

homer911

Most Paint manufacturers do special paint for Kiitchens and Bathrooms - sounds like it would be appropriate here

brian__foley

homer911 wrote: »

Most Paint manufacturers do special paint for Kiitchens and Bathrooms - sounds like it would be appropriate here

It was suggested to me that there is a paint that is used for the hull of boats that could be useful as an undercoat for this problem. Not sure whether its true or not!

mad m

brian__foley wrote: »

It was suggested to me that there is a paint that is used for the hull of boats that could be useful as an undercoat for this problem. Not sure whether its true or not!

Thats Anti-fowling paint, its meant to stop organisms attaching to underside of boat...

They sell this stuff Zinsser Paints in MRCB, its expensive but its meant to give 5years guarantee against mould re-growth..You have to finish walls in this paint though....You can tint paint to a colour.

Robbie71

Zinheisser is good stuff but may i suggest a paint additive before this - Insulatex.
theory is - two coats of paint (soft sheen) with Insulatex will greatly reduce the amount of condensation ,
I have used this in a badly affected apt. and am waiting to see how effective it is.
The wall was definitely warmer to touch afterwards. The company makes a lot of other claims about heat retention etc but its worth a shot on even one wall to try out, about €20 for 5l
i have also used Mould Stop additive which works for 6 months to a year
You could use a top coat of Zinheisser.

brian__foley

I'd be surprised if these are really an all-in-one solution if there is condensation. If there is moisture, and these paints make sure that, in one way or another, it doesn't settle on the paint, it'll have to settle elsewhere I assume. Probably a good combination of painting, installation of vents, and general decent management of air circulation (opening doors, keeping clothes cupboards slightly less than totally full) etc is the way forward!

My own little problem is a bit more annoying - the wall on which there is most condensation problems was re-plastered reasonably recently. I wasn't impressed with the job as portions of the skim are bulging elsewhere (away from the condensation) but in the condensation areas, it is positively crumbling and coming away from the walls.

I'd be happy to throw money at anyone on this, but the more I hear about people hiring "damp" experts etc, the more hesitant I am about going near anyone. I'd nearly assume it would be best to get someone who works in a good reputable property management company (as I assume its apartments which are creating this issue all over the place) on a nixer!

brian__foley

Robbie71 wrote: »

Zinheisser is good stuff but may i suggest a paint additive before this - Insulatex.
theory is - two coats of paint (soft sheen) with Insulatex will greatly reduce the amount of condensation ,
I have used this in a badly affected apt. and am waiting to see how effective it is.
The wall was definitely warmer to touch afterwards. The company makes a lot of other claims about heat retention etc but its worth a shot on even one wall to try out, about €20 for 5l
i have also used Mould Stop additive which works for 6 months to a year
You could use a top coat of Zinheisser.

What about applying some internal insulation? I have an alcove which is badly affected (less air circulation etc) and was thinking that since it's out of sight really, I may treat it as you suggest and then apply some polystyrene (or whatever is good) sheets over that, cover that with 6 mm plywood and skim that for appearance. I assume the walls in the alcove wouldn't have such a differential in temperature then to cause the problem.

Robbie71

There is no substitute for ventilation and insulation and the paint additives are only necessary where the a redoing the wall insulation is too costly or if there is no alternative.
Many apartments have bathroom fans that are not powerful enough to carry air through long pipe runs to the exterior outlets. The pipes are not insulated and the moist air condenses and flows back into the fan.
Paint additives may help in 'dead air' areas behind curtains or in your alcove.
If you are doing your alcove you can get 25mm foam backed plasterboard for about €25 for 8x2 sheet,plaster and standard paint .

brian__foley

Robbie71 wrote: »

There is no substitute for ventilation and insulation and the paint additives are only necessary where the a redoing the wall insulation is too costly or if there is no alternative.
Many apartments have bathroom fans that are not powerful enough to carry air through long pipe runs to the exterior outlets. The pipes are not insulated and the moist air condenses and flows back into the fan.
Paint additives may help in 'dead air' areas behind curtains or in your alcove.
If you are doing your alcove you can get 25mm foam backed plasterboard for about €25 for 8x2 sheet,plaster and standard paint .

Thanks, that's great. It's a small house actually and every inch is needed so, unfortunately, I think putting internal insulation in the room is out (there is none at all!). I am "lucky" enough, though, that I can put direct vents into the open air. We'll see how it goes and maybe I'll have no choice but to lose a few inches in the future. That said, the house has stood for over 100 years, so the problem is most likely human interaction and (to date) bad management of air circulation.

cubix

Similar problem but with a twist. An external wall in a ground floor apt was having mould issues. Wall was insulated with what I think was 50mm kingspan/slabed & skimmed. Vent in the room is a 9"x6" one I think and is clear. Mould has returned albeit in behind the free standing wardrobe that stands against this outside wall. Apt is heated by electric storage units. All heaters are hung on internal walls.
One thing I wondered, in my own 2 storey house(10yrs old with only fibre glass in between the batons) the rads in all the bedrooms are on the outer wall and under the windows. So far I have never had a mould issues and wondered if this was a factor?.

johndaman66

Robbie71 wrote: »

Insulatex.
theory is - two coats of paint (soft sheen) with Insulatex will greatly reduce the amount of condensation

Could somebody please advise me where this may be sourced. Will need to do some considerable renovation first though. Have a quite severe problem with a kitchen that is used exclusively for cooking and washing dishes/clothes. The main problem is that there is no extractor fan over the cooker. Could anyone please advise on how much i would be talking for the supply and fit of an extractor fan? Space is already at a premium so any internal insulation that would eat away at internal space to any large extent is an absolute non runner. Probably will end up dry lining the walls though I'm sure.

Also in the Winter the floor gets very damp even if there is no traffic on it which suggests rising damp/ a punctured damp proof course to me. It was suggested to me at one stage that the floor should be dug up and a paste put on underneath. Has anybody got any experience of such a job?

dunsandin

Being a lazy tinternetta, ive not read most of the replies, so sorry if im repeating someones reply. You can paint the walls with bramley apple jam if you like, and it will not solve the problem. 1.introduce a bit of heat to the room. It will help, but not fully solve. 2.run a dehumidifier, but its noisy, inconvenient and hardly ideal. 3.re-line and insulate the wall affected & get a 5" core bit, drill a hole through the external wall and bung in a bit of 4"sewer pipe with a vent cover each side. Apart from 3, they are all only sticking plasters. BUT, you must be sure that you dont have an outside scource of moisture before trying this route. Is there a leak above you? Is there leaky gutter or flashing close by? Is there a leaky pipe in the room above? Black mould can be from condensation or from a moisture ingress, its either caused by water condensing on the cold wall, or moisture ingressing from another scource. Full offence intended, but a lot of damp proofing companies talk a lot of sh1te to make a sale. Go for 3. or a leak fix. Just a thought, but your roof not leaking is it? Have a reallyyyy good look at the roof covering above also.

johndaman66

Many thanks dunsandin. I think as you mention puting a vent in one of the walls should help so will certainly arrange to get that job done. Will try to arrange to get some quotes for dry-lining over the next few weeks. As mentioned any thick insulation on the inside that would eat into space to any great extent is a non runner due to space being at an already very tight premium. The house being built in the mid 70's would mean that the size of the cavity is by no means large I would possibly imagine so may need to consider exterior insulation. Have heard that this can be very expensive and it is a brick built house also. Although there is a small heater in the room what heat comes off it is not worth talking about. It is run off a solid fuel stove as are all the other heaters in the house. All other heaters in the house give out reasonable heat except for this one and another one also where the pipe work is running along the ground....for the heaters that do give out reasonable heat the pipe work is coming down from the attic. For the two that give poor heat the pipework is running along the ground

Will have a better look at the roof over the upcoming long weekend. As mentioned previously there would appear to be considerable damp on the floor with even mild rain, despite no traffic and it would even be damp in the centre not just around edge of floor...this is kind of worrying to me. Also should have mentioned that the house is a bungalow so theres no room overhead

dunsandin

John, you don't need thick insulation. Thats a pure myth. You can buy foil based insulation, a bit like aluminium bubble wrap- its just 5mm, with a 25mmbatten and a 12mm sheet of gypsum, you've just added 42mm, and thats not a whole lot. We normally use this to insulate, and add a 25mm slab of polystyrene insulation between the battens. This gives a HUGE improvement in the U value of the wall, but does not intrude into the room too much. The room will be transformed in terms of warmth, and in terms of dampness.
Just as a side note, my whole house is done like this, and its 8000sq ft, 300 yrs old, and toasty warm with a single solid fuel back boiler running 8 rads. Cant get much better than that in terms of cost/sq ft to heat.

johndaman66

Many thanks dunsandin, your advice is most helpful and much appreciated. I have a few weeks off in August so will look to getting the kitchen done then. In the meantime will arrange to get some tradesmen around to price the job for me.

dunsandin wrote: »

Just as a side note, my whole house is done like this, and its 8000sq ft, 300 yrs old, and toasty warm with a single solid fuel back boiler running 8 rads. Cant get much better than that in terms of cost/sq ft to heat.

Wow, thats much different to my scenario. I have 7 heaters being run from the solid fuel stove. Five of them heat up reasonably well after a good fire is on for some time. The other two are a dead loss really. I would think its a circulation problem. Bleeding the radiators is of no assistance either. I installed the system about 3 to 4 years ago and to be quite honest the plumber was a bit of a chancer and not very competent or at least his apprentices weren't in some respects. We learn by our mistakes. Out of curiosity do you have some form of pump circulating the heat around the house? Forgive me if I sound somewhat green when it comes to these sort of things.

Many thanks again for assistance dunsandin.

dunsandin

John, I installed the system myself, to a drawing done by a brilliant plumber who does work for me. I incorporated 2 circulation pumps in series, to really move the water, but the whole bleeding/no heat thing is usually down to poor radiator balance. As the water travvels away from the heat scource(the stove), you need to modify its flow characteristics, ie the radiator nearest the stove needs its valve just open a little(thats the one on the left that you open/close with a wrench) in order not to "hog" the hot water. The next one needs to be open a little more, the next some more, and so on around the circuit. This is a bit of a black art, but when done correctly, all of the rads will have broadly similar output. The one provisio is that the stove must be fit to heat sufficent water for all the rads-if the snailsman in the store says it will heat 12 rads, figure 8. If he says 8, figure 5. The whole gig really is insulation though, the upper storey of my home has No heating. But it is in no way at all cold, and is in fact comfy warm, But I have gone to town with the whole insulation thing. I was down in Laois with a mate who was putting up a Nudura home, and it was a whopper, and there was a superser in the hall, heating the whole house on a bitter winters day - the heat just couldnt get out, so the house was snug.