Black Mould

lindsay689

Hello, I am looking for some advice on some black mould I am getting in my house.

My house is a 1995 detached bungalow. I have vents in every room in my house. I do not have the finances at the moment for insulation, new windows etc.

I am getting a relatively small recurring issue with mould in my bedroom. It is specks of black mould on my ceiling, close to the an exterior wall, and the same goings for my ensuite (ceiling connected to the same exterior wall). This happens every winter, I keep on top of it by killing the spore with bleach, vinegar et cetera I also repaint that section of my ceiling every year with anti-mould paint. Again it’s not a major mould issue, but I’m just concerned at the fact that it comes back re-occurring during the winter and I am looking to try and solve it. Someone I know has gone up to the attic and tried to feel around for damp up there, but it’s a bit difficult as it is not floored. They said they could not find anything

I find it peculiar that it is only on one side of the house, in the same by the same exterior wall. I would love to try and kill it at the source. I will add that the side of my house that I am referring to is a bit damp in general outside, as there is a hedge there and not a lot of light gets in. Obviously this is in reference to the ground more than anything so I can’t see how this would be connected to my ceiling inside the house? Other than that I do have two patio doors in my bedroom that are only four years old and are drenched in water every morning during the winter. I have had multiple door people out to look at it and he cannot see any faults with it, there is a vent next to the doors. Every morning I use a wet vacuum to suck up all the water, and turn on my dehumidifier.

Thank you for any advice. 😃

Alkers

Is the attic insulated? Can you check that the insulation is covering this section of ceiling as it does elsewhere.

Water vapor is condensing there as it is cold and this is allowing mould to grow.

The remedy is improved heating and / or ventilation.

ottolwinner

I agree with the above post. Improved heating avoiding letting the temp fluctuate too much in the environment.

I installed a envirovent system in my place few years back. Not had a problem since but it may not be all you need.

Gusser09

Ventilation. You have too much moisture in the room.

Also a dehumidifier would be a really good investment.

Its a tricky enough fix to be honest.

I just installed a piv today to improve ventilation in the house. A couple of hours to get it done.

It has a vent cover

tikka16751

Open the windows during the day and let fresh air in.

Kaisr Sose

https://www.boards.ie/discussion/comment/121552607#Comment_121552607

Interesting!

If the insulation is missing, would that not be the cause, rather than ventilation or more heating? The latter would be much more difficult too where insulation is not as good as it should.

I have experience of this myself. I am in a top floor apartment. All I have between my home and the roof slab is foil backed plaster board. Property was built in 2005/6.

I have mould, on ceiling and corners of walls. I vent and heat as much as I can. Lack of insulation means heat escapes faster than it should. I have a dehumidifier but would rather the cause of problem was fixed than wasting money on the symptoms.

BryanF

https://www.boards.ie/discussion/comment/121552659#Comment_121552659

OP

Recommend the above,

you said this is happening principally in your bed room?

If so, do you get condensation on the windows at night?

if so start by leaving window in bedroom ajar at night. Rough rule of thumb: 1pint h2o added to the air per person over night etc.

re attic and mould at ceiling: this may be the coldest spot in the room, this may be where ceiling timbers have reduced attic insulation - moisture laden air over night ‘condenses’ on the cold ceiling forming mould.

start by cleaning and keep windows open an inch at night.

Alkers

https://www.boards.ie/discussion/comment/121552677#Comment_121552677

The reduced insulation in one section just means that's the coldest section of wall / ceiling, where water vapour is most likely to condense, causing damp leading to mould.

You could also take the covers off your vents, ensure they are free from dust etc. Do you sleep with bedroom door closed, you could try opening it, passive vents like that might not ventilate much if there's no internal airflow

denismc

I had an issue like this a few years ago, I had mould growing in a small section of the bedroom ceiling, when I investigated I found there was a small section of insulation missing.

As someone else pointed out moisture will condense on the cold section where the insulation is missing.

Tippbhoy1

Do you shower with the en-suite room open, or leave the door open after showering? If so, all moisture from the en suite is making its way into the bedroom, and your room is full of moisture. If you aren’t getting a mold problem in the bathroom I would say almost certainly there is an insulation issue in the ceiling in the bedroom.

cheap fixes

a roll of insulation and place it in the attic in that area, ensuring it’s pushed down to the eves properly

check vent in bedroom is clear

fit an extractor fan in the bathroom if there isn’t one

open windows after showers

use cillit bang mold remover. I was breaking a problem area for ages before then used this once, and it never returned

Furze99

https://www.boards.ie/discussion/2058328945/black-mould

"Other than that I do have two patio doors in my bedroom that are only four years old and are drenched in water every morning during the winter. I have had multiple door people out to look at it and he cannot see any faults with it, there is a vent next to the doors. Every morning I use a wet vacuum to suck up all the water, and turn on my dehumidifier."

What's this about? Patio doors are often large glass surfaces, is moisture condensing on these at night or is there water 'drenching' them some other way? What quality is the glazing? Glass is always going to be cooler than block walls with insulation. But you'd want a fair bit of moisture in the air for it be drenching them in condensation every day. Doesn't sound right.

kaizer13

Interesting to see so much advice and quite frankly much of it is very good but there are some absolutely wrong tips.

Black mould should certainly be avoided and prevented where possible. It is usually the result of moisture laden air condensing onto surfaces that are allowed to drop below (generally speaking) 16 degrees Celsius. This is a key fact and must be considered when ventilation is being cited as a solution. If the left open window or even built in room ventilators are allowing in air that is below that temperature, then the problem will not be solved.

lindsay689 has a dehumidifier but apparently this only goes on in the morning. Too late, the water vapour in the air has already been allowed to condense onto cold (and worse still, into) surfaces and fabrics. The symptom of black mould on ceilings near external walls is usually indicative of poor installation of insulation. I have been working in lofts since 1965 when insulation of roof spaces became a building requirement and it is very rarely that I have come across well installed material. The eaves are difficult to get to to do the job right....and who is going to see it anyway? Well, it eventually becomes apparent, in the form of black mould.

lindsay689 I could go on for it is a very complex subject, but could be affordably resolvable. Ventilation certainly plays a part in the solution but it has to be used intelligently. Key points to remember. All human and animal activity produces moisture. Just breathing, let alone bathing, cooking, washing etc. You cannot live without filling the air around you with water vapour. That water vapour, desperately wants to become water so it will seek out any fabric or surface that is cold (below 17 degrees Celsius) and will condense on or within it. In your case, the loft insulation could have been badly fitted in the eaves or may even have been blown out of position by wind. Your ceiling is getting cold enough for surface condensation to occur. Day and night, that ceiling temperature has to be maintained. You cannot do that at this time of the year by leaving windows open or by using the built in room vents. Any openings to the outside including fireplaces, which are just fancy holes in the roof, designed to let out warmth should be sealed off. KEEP EXPENSIVE WARMTH IN THE BUILDING but use your dehumidifier to extract moisture from the air as it is produced. Do not waste using your dehumidifier if you have any openings to the outside, no point in trying to dry out the planet.

Windows can be used very carefully to change the air in any particular room. The average sitting room for example, only needs a window to be open for about ten minutes for the air to freshen. Any longer than that and the cold at this time of the year will come in and your surfaces will become cold enough for condensation to occur again.

Others have commented upon products used to remove the mould and to help prevent it coming back, that is chemical warfare, and it has a place in this battle. My comments are based upon an understanding of physics and of many years of practical experience. There is more, but enough for now.

listermint

Due to location this is most definitely related to the insulation near the wall plate being missing or lifted allowing excessive air under the insulation at that spot , this is cooling the ceiling allowing moisture to condense.

We had that in 2 spots in our bungalow when we moved in, got into attic and the insulation was shifted back away from wall plate. Pushed it further out to the plate and made sure gap was still there between the roof and the top of insulation so air could flow over it but not under. Added more rolls too later on. But it cured it immediately. Cleaned the area with bleach and it never returned.

Very cheap repair (free)

Gusser09

https://www.boards.ie/discussion/comment/121552659#Comment_121552659

Too much moisture in the outside atmosphere. Doesnt really work well

tikka16751

https://www.boards.ie/discussion/comment/121554868#Comment_121554868

Keep your windows closed so.

Kaisr Sose

https://www.boards.ie/discussion/comment/121553826#Comment_121553826

I leave all doors open to keep air moving and to help heat the place as warmer air from hall can move to other rooms

There is absolutely no insulation in the ceiling void anywhere in my property. I had my heating on for 5hrs this evening and living room temp is 17.3c. It's not even cold out.

I am pretty sure the roof void is not sealed properly and on windy days, even moderately, it's very hard to heat my home. With air cycling up there the heat I am loosing is being replaced with cold air. On a still frosty day, I have no problem hearing my home to 20c , which is warm enough.

I thing I am fight more than just no insulation. Moisture is getting in to the void from the roof as I have dead earwigs in my bathroom ip54 spot lens. They would only be there is the void was damp.

Even ln in summer time I have problems. In fact, mould growth and it's speed accelerates in summer time. I don't really have condensation problems, so I am at a loss to what is causing the mould when there is no cold temps or condensation .

Gusser09

https://www.boards.ie/discussion/comment/121556240#Comment_121556240

Mate get your attic done. Even a diy job is cheap as chips and would work wonders.

Kaisr Sose

https://www.boards.ie/discussion/comment/121556620#Comment_121556620

I live in a top floor apartment. Above my ceiling is the concrete roof slab. I would gladly insulate it, but I have no access, I am going to get an engineer to have a look at options. I have sort of had it now with high heating bills, sadly without getting a warm home.

Sorry for deraiing your thread OP. I will ask the moderators to create a new thread for my issue

I hope you can get your own issue fixed. I can't offer much advice other that insulation being the issue if there is no damp in the attic and the rest of the home is ok. You seem to have a lot of condensation. I don't see leaving windows open for long periods will solve this.

Gusser09

https://www.boards.ie/discussion/comment/121556691#Comment_121556691

Possibly insulate the internal ceiling. Hope you find the issue.

listermint

https://www.boards.ie/discussion/comment/121556691#Comment_121556691

I'd be quite surprised if the ceiling wasn't insulated in some way. Have you cut a slot in the plasterboard to see if there is insulation or just a void.

Conventional method would be pull out ceilings batten ceiling and put in some fire rated PIR board glued and screwed. Then replasterboard.

magicbastarder

https://www.boards.ie/discussion/comment/121554824#Comment_121554824

"That water vapour, desperately wants to become water so it will seek out any fabric or surface that is cold (below 17 degrees Celsius)"

citation required? surely it's dependent on other factors, such as relative humidity etc.; suggestion you'll get condensation if the walls drop below 17C seems a bit simplistic.

Kaisr Sose

https://www.boards.ie/discussion/comment/121556771#Comment_121556771

100%, just 12mm plasterboard

See photo. Lower is ceiling, top is roof slab.

What you outlined is the solution. It's a messy job, and who pays?

I am going to get an engineers report on this and submit to OMC.

BryanF

https://www.boards.ie/discussion/comment/121556208#Comment_121556208

https://www.boards.ie/discussion/comment/121554868#Comment_121554868

you need fresh air. Suggest researching ‘relative humidity’ see link below to psychrometric chart

https://www.rotronic.com/media/productattachments/files/h/o/how_to_read_psychchart_f_web.pdf

Gusser09

https://www.boards.ie/discussion/comment/121557434#Comment_121557434

A vent of some sort for sure.

Opening a window will help cool down the surfaces where the moist warm air gathers. Id open it for no more than 10 mins.

Real world scenarios around air leaks, mould and mositure differ from the stuff online.

lindsay689

https://www.boards.ie/discussion/comment/121553455#Comment_121553455

I do not have any windows in my bedroom, only the French doors. I ventilate my house but it is a bungalow and we are at work all day. As said before I have vents in every room of the house to help with ventilation.

lindsay689

https://www.boards.ie/discussion/comment/121554065#Comment_121554065

Yes doesn't sound right but had multiple people out to look at them and they can't understand why it's happening. (they are double glaze) It is condensation, moisture gathering, but it is from the top of the glass all the way down to the bottom of the glass. Obviously I come across moisture onto my windows at times and it's only a very small amount, for whatever reason these double glass French doors are soaking every winters morning. Before I bought my wet vacuum I used two hand towels to get they dried there was so much water.

Gusser09

https://www.boards.ie/discussion/comment/121559608#Comment_121559608

Are the reveals facilitating a cold bridge? Might be worth checking this out. Is there any damp or mould on the plaster work?

loyatemu

https://www.boards.ie/discussion/comment/121556970#Comment_121556970

yeah, the dew point is dependent on the RH of the air as well as temperature. If you can keep RH down either through ventilation or a dehumidifier, it reduces the surface temperature at which you will get condensation.

Something else to be aware of is that human breath contains a lot of moisture; I've noticed in my kids rooms that the walls and ceilings above the head of their beds are the areas most prone to mould. Where I can I've moved their beds away from cold external walls. I assume it's like breathing on a mirror, even if the RH in the room is low, you'll still get condensation because the humid air being breathed out doesn't get a chance to disperse before it hits the cold wall surface.

fergiesfolly

https://www.boards.ie/discussion/comment/121552655#Comment_121552655

Do you mind if I ask how much that cost?

https://www.boards.ie/discussion/comment/121569054#Comment_121569054

I got the HC Link

https://drimasterexpress.ie/

ottolwinner

Is there more complaints of mould now than ever?

Gusser09

Houses are more airtight than ever so that could explain it.

I find leaving my internal bedroom door open a few inches at night also helps the ventilation and preventing condensation.

Alkers

https://www.boards.ie/discussion/comment/121569308#Comment_121569308

Would you not achieve the same in having an extractor fan running constantly and at least then have control where humid air is leaving the house?

tom23

https://www.boards.ie/discussion/comment/121552629#Comment_121552629

Was it expensive?

listermint

https://www.boards.ie/discussion/comment/121570413#Comment_121570413

Wheres your supply air coming from then.

ottolwinner

https://www.boards.ie/discussion/comment/121585059#Comment_121585059

It cost €250 for the assessment and then €1300 for the envirovent product. There initial assessment was then discounted from it. What I liked about it was he did a full assessment of the house first and a list of options that would all lead to less problems. He did stress that education was important though in that heating and ventilation were important but not as in creating a furnace then letting it all out the window.

in the long run it has saved countless hours of cleaning mould, improved my asthma to huge degree and given peace of mind.

AndrewJRenko

https://www.boards.ie/discussion/comment/121585181#Comment_121585181

Do you have to run the fan at night to get the benefit? I'd be worried about the noise.

listermint

https://www.boards.ie/discussion/comment/121586036#Comment_121586036

These are automated. Your meant to leave it alone. It detects humidity and some do air quality like CO2. You don't touch it.

AndrewJRenko

https://www.boards.ie/discussion/comment/121586750#Comment_121586750

So it would be switching itself on and off during the night? Is that workable for a bedroom?

listermint

https://www.boards.ie/discussion/comment/121587340#Comment_121587340

It would yes , depends on the unit different manufacturers will have different dB metrics. Depends on motor fan design etc. Some may be highly noticeable some not.

However these types of units are mainly designed for wet rooms. Bathroom kitchen utilities. Rather than bedroom. They are meant to pull a flow towards the wet rooms and out. Bedrooms wouldn't be classified in these.

ottolwinner

https://www.boards.ie/discussion/comment/121586036#Comment_121586036

The device exchanges the air 8 times a day in the house. It’s runs all the time and adjusts as needed. it sits on the wall or in the attic depending which you choose.

noise. You’ll hardly hear. I am constantly checking to see if mines on its so quiet.

costs €19 a year to run it electricity

AndrewJRenko

https://www.boards.ie/discussion/comment/121587712#Comment_121587712

Thanks, does it need to be in the particular room where the condensation is appearing, or does it work in any room of the house?

TimHorton

https://www.boards.ie/discussion/comment/121587712#Comment_121587712

model number ?

ottolwinner

https://www.envirovent.com/products/positive-input-ventilation-piv/atmos/

not sure of model number this is the product I have

ottolwinner

Mine is located in the hall do I suppose it’s central to all rooms

it will circulate with room doors closed provided there is a 7-10mm gap below each of them.

all that is visible in the hall is a ceiling vent.

listermint

https://www.boards.ie/discussion/comment/121588302#Comment_121588302

Gaps should be ideally 15 to 20mm under doors.

ottolwinner

https://www.boards.ie/discussion/comment/121588387#Comment_121588387

Wouldn’t be too up to spec on that listermint but the device just states it needs min 7-10 mm. I suppose to let anyone with those draft protectors or bristles on the bottom of doors be aware a gap is needed.

listermint

https://www.boards.ie/discussion/comment/121588695#Comment_121588695

Your doors should generally have that gap under them from install. It's not enough tbh for good flow supply you'd double that normal door gap.

listermint

https://www.boards.ie/discussion/comment/121587712#Comment_121587712

I've worked out that our central MHRV is around 50 Euro to run for entire year. If I opt to use the built in heater resistor which warms the air further it ramps up the cost. But in non heater mode purely ventilation it sips electricity juice not thirsty at all.

Alkers

https://www.boards.ie/discussion/comment/121585087#Comment_121585087

From the vents in the walls?

You you have continuous extract in wet rooms, can be humidity controlled also and fresh air being drawn in through vents in other rooms (or wherever else there is poor air tightness).

By doing the opposite with the PIV, you're blowing fresh air into the house and consequently you're also blowing the damp humid air out of the house - hopefully through the vents but that air will also be pushed into anywhere else that has poor air tightness and could be condensing in all those places, increasing risk of damp and mould.