Black mould and dampness

bruce thomas

Hi folks 

I have a problem with condensation and black mould in my house. 

I know from my research that it’s because of poor air circulation. 

after doing a google search I’ve come into contact with the damp master and there going to call to my house in two weeks time to conduct a survey costing me 450€. 

wha i want to know is have anyone used damp master before and were they happy with their work, price , equipment etc etc 

thanks for reading my post and for your help in advance

10-10-20

I'd correct this "I know from my research that it’s because of poor air circulation. " to say "I know from my research that it’s because of poor air circulation AND human activities such as cooking and cleaning and drying clothes."

That way you can understand that your activities are part of the reason why moisture is high. Addressing some of these - by drying outside or by using a dryer or using an externally-vented extractor fan during cooking - will reduce some of that moisture. 👍️

Hopefully this helps.

MicktheMan

Not lack of air circulation but lack of effective/efficient evacuation of moisture is likely your issue caused by one or more of the following:

• Homeowner's lack of knowledge on the natural physics at play and often being counterproductive because of this.
• Excess moisture load
• Insufficient heating maybe caused by excessive heat loss
• Poor / ineffective ventilation.

From experience, the only manner to successfully address which of these are the culprit(s) is to monitor & log the internal air conditions over a period of time (e.g. 2 weeks) and then using the data collected in conjunction with a visual / thermographic survey to make appropriate recommendations.

Anything else is guesswork really and maybe a pushy sale of some ventilation system. Also, the more independent your advisor/surveyor is the better.

FlipperThePriest

Just to add a bit of background, the OP has posted this in the regional forums, and has blocked their vents. I suggested the OP should unblock vents and maybe look at reducing direct wind through vents.

https://www.boards.ie/discussion/2058279314/dampness

Good luck OP!

So they're charging you 450 euros just to have a look at it?

bruce thomas

What they said was to carry out a survey to find out what’s the cause and then advise me on a solution

Biker1

So you are getting a company that want you to buy their product to do the survey. They are going to tell you that you need their product to solve the problem whether it is right for your issues or not. At least get independent advice if you are going to pay 450e for it.

Calahonda52

https://www.boards.ie/discussion/comment/120098856#Comment_120098856

I would agree with Biker here and also with post 3 by MtM.

Just to add my piece to the above: we need to consider the the level of insulation and the role of relative humidity.

IMO I would ditch the damp mister call out for now, post some contextual pictures of the mould here and let's have a shot.

Also tell us why kind of house it is.

The resolution here is science/physics/ household occupancy/behaviour profile based and not product specific based which is what damp mister will offer.

As for mould resistance paint....

I have just finished surveying 50 houses in Kerry and am still learning about mould etc.

https://www.boards.ie/discussion/comment/120098719#Comment_120098719

The cause is insufficient insulation combined with inadequate or inappropriate ventilation. Warm moist air + cold surface= condensation = mould.

The solution is insulation + ventilation. For ventilation, mechanical extract from the bathrooms & kitchen (ie where most moisture is generated) would give the most return on investment. The attic will provide the best return for the money spent on insulation.

The best solution is to ensure air tightness (replacing doors & windows as necessary) and insulate all your external walls, your floors, your attic, and install a centralised mechanical ventilation heat recovery system with humidity sensors.

You can PM me for my bank details so you can transfer the €450...

Calahonda52

So you want the OP to spend maybe 150k on a house that will still be worth what is worth before the 150k spend.😎

bruce thomas

Thanks for that

the House is well insulated both walls and attic

yes i agree that ventilation is key.

as i said previously i blocked the vents in the walls of some rooms because they breeze coming in was unbearable.

my question is could you recommend a ventilation system ie centralised mechanical ventilation heat recovery system

are they like a heat exchanger in the attic pipped to each room.

bruce thomas

Thanks

upload pics later

house was built 25years ago, with 2 inch areo boards in the cavity, and maybe 4 inches in the attic. About 10 years ago we got the walls pumped and extra insulation in the attic. It’s a 2 story building and 5 people living in it.

as i mentioned earlier i did block the original vents in the walls as the breeze coming through was unbearable.

i think that’s my problem and I’m asking would a heat exchanger system sort it out?

MicktheMan

https://www.boards.ie/discussion/comment/120099058#Comment_120099058

Couple of points.

Don't block vents.

If unbearable breeze is coming through vents then you likely have a general air tightness issue throughout the house effecting your comfort and heating bills negatively (aka draughts). This is separate to insulation and should be investigated as part of the independent survey.

The Vent Axia multivent range of central mechanical extraction systems are decent for your situation without breaking the bank and far superior imo to PIV systems I see advertised regularly. Forget heat exchangers or heat recovery systems if you don't have a handle on your air tightness.

bruce thomas

Hi again and thanks

can you explain to me what the centralised mechanical ventilation heat recovery system does and compare it to a heat exchanger please

bruce thomas

Also can you advise me on who would i get to do an independent survey on this.

thanks

XsApollo

Have you a boiler inside the house?

if you do ,is it gas or oil?

You need big vents if you have a gas boiler inside.

You shouldn’t really block your vents, especially if you have any type of boiler inside.

maybe put a different vent on the outside that restricts the flow more.

or alternatively I did this myself was put different vent on the inside that you can close and open.

if it’s **** weather you close the vents , especially good at night, and open during the day or a more suitable time.

New2Dubs

We had similar problem with mould in bedroom which has 2 external walls. We realised we’d not been ventilating each day with fresh air because of the cold weather. Bought a dehumidifier online & have stopped drying clothes on radiator in bedroom. These 3 small changes have made a huge difference.

MicktheMan

https://www.boards.ie/discussion/comment/120099258#Comment_120099258

Heat recovery is the process of extracting the heat from the exhaust air and transferring it to the fresh incoming air. This process happens in the heat exchanger.

Don't get too hung up on this though, what you need is appropriate ventilation not necessarily the latest gizmo.

bruce thomas

https://www.boards.ie/discussion/comment/120099274#Comment_120099274

oil burner it’s outside

I know i shouldn’t have blocked the vents but where i live i had to keep out the breeze coming through

im looking for an alternative solution thanks

bruce thomas

https://www.boards.ie/discussion/comment/120099299#Comment_120099299

Thanks

but I’m looking for a different solution to vent’s on external walls

New2Dubs

I didn’t mention vents (we hadn’t been opening windows) but good luck!

Calahonda52

https://www.boards.ie/discussion/comment/120099265#Comment_120099265

Where are you living?

This is key to seeing who might look at it.

MicktheMan

https://www.boards.ie/discussion/comment/120099265#Comment_120099265

PM sent

https://www.boards.ie/discussion/comment/120099009#Comment_120099009

No.

The tongue in cheek reference to the "best" solution was partly in reference to the OP's enthusiasm for throwing €450 for someone to come and try and sell him an expensive solution to his reasonably simple problem. It was also partly a reference to some posters insistence that the absolutely perfect, comprehensive, and model best practice solution is the only option that anyone should ever even consider possibly considering when addressing any issue. Which is ridiculous.

If I was the OP I wouldn't want to spend Christmas dealing with the issue. 2 or 3 extractor fans in the bathrooms & kitchen plus a ton of insulation in the attic would be my approach— quick, cheap, effective, and guaranteed to completely horrify a significant proportion of the posters in this forum...

mosii

https://www.boards.ie/discussion/comment/120099299#Comment_120099299

Hi ,I agree with this approach, open windows to ventilate but not too long, keep as much heat in the house. A dehumidifier will help .A meaco 10 L 180 euro ,cheap to run so dont be afraid to use .A big cause of condensation is drying clothes inside, on rads etc. If you put your clothes in a small confined area ,and use the dehumidifier to assist drying ,this will help. I was skeptical of dehumidifiers ,but they can collect a lot of moisture from the air, thus reducing condensation and mould. Best of Luck.

C. Eastwood

https://www.boards.ie/discussion/2058279321/black-mould-and-dampness

S - ( I + V) = C

This is a simple way to explain Condensation.

S. Steam

I. Insulation

V. Ventilation

C. Condensation

You state that your house is well insulated.

And that you will open up the Vents

Then the problem is Steam.

This Steam is caused by the following:-

1. People breathing
2. Drying clothes on rads
3. Steam from boiling water, boiling vegs, cooking, etc
4. Baths
5. Showers
6. Tumble Dryer
7. etc sources of moisture

Clothes should not be dried in the house.

Tumble Dryers must be exhausted to the external atmosphere

During cooking- extract steam to the external atmosphere and have the Kitchen door closed to prevent any steam escaping in to other parts of the house.

When finished having a Bath / Shower, open the Bathroom window / switch on a Mechanical Extractor and shut the door of the Bathroom on leaving.

Also seal all draughts to prevent heat loss by Convection.

bruce thomas

You haven’t read everything

what family does everything that you say.

in theory you may be right but in practical kids don’t open there windows first thing. Who closes doors when cooking. I’m out of the house very early every morning and late home. So I’m looking for another solution to ventilate my house during the day rather than opening windows and closing doors. Also most people i know are drying their clothes on a clothes horse. I’m no different to anyone else. I’ve a problem with air circulation and that’s why i have mould so I’m looking for better options. that’s what I think. Thanks anyway for your input.

Calahonda52

https://www.boards.ie/discussion/comment/120100328#Comment_120100328

Steam is not the right word here, the correct terminology is water vapour contained in the air, which then condenses out as water when conditions are right: a combination of lower surface temperature and higher relative humidity as shown below.

Steam has a minimum temperature of 100 degrees Celsius at normal atmospheric pressure.

If you look closely at the spout of a kettle when boiling, you cant see the first few mm as its steam.

Once the temp drops and the steam becomes water vapour, then you can see it.

Calahonda52

https://www.boards.ie/discussion/comment/120101351#Comment_120101351

did you post the pics and tell us where about you live yet?

Re your comments, some of this will require behavioural change, we can't rely fully on tech, especially when it consumes more scarce energy

TimHorton

https://www.boards.ie/discussion/2058279321/black-mould-and-dampness

Any Pic's. Had black mould along the edge of an external wall, Cleaned it with Vinegar/Baking Soda - I then went up into the attic and discovered the Attic Insulation near the eaves just above the mould was not fully there - Whoever put it down was too careful not to block airflow. I simply relaid half the length ensuring airflow remained but making sure I got good coverage - Hey presto 2 months later I have no mould on the relaid piece but on the part I did not remediate they black mould returned.

Calahonda52

https://www.boards.ie/discussion/comment/120103737#Comment_120103737

https://www.ecologicalbuildingsystems.com/post/how-to-insulate-your-loft-with-natural-insulations

Not proving the company, just the science/ ideas

C. Eastwood

https://www.boards.ie/discussion/comment/120101598#Comment_120101598

I fully understand steam.

People breathing do not produce steam, etc

https://www.boards.ie/discussion/comment/120101351#Comment_120101351

First, just because everyone you know is drying clothes on a clothes horse doesn't make it a good idea (15% of adults smoke, but the mere fact that half a million people do it doesn't make it clever). At bare minimum the clothes horse should be located in a well ventilated part of the house.

Also, and just to be clear, you're willing to pay €450 for a consultation leading to paying at least several thousand euro worth of a "solution" but you're not (for example) willing to set a tumble dryer on a timer to come on in the middle of the night at a cost of maybe €1 per dry?

Or to put it another way, you could dry a load of washing every night for almost a year and a half (taking a couple of litres of water out of your home's atmosphere per day) for the cost of just the consultation. For the likely cost of the consultation plus the "solution" you could run a dryer every night for at least a decade (and probably 2 decades) while replacing the tumble dryer several times along the way. Closing the door & opening the window of the kitchen for half an hour while you're cooking is effectively free.

Put a third way, the solution likely to be recommended will likely cost a few months wages. So do you really prefer to work full time from now until mid-April just to avoid the inconvenience of setting the tumble dryer on a timer and closing 1 door and opening 1 window while you're boiling potatoes?

Finally, if you're asking for suggestions you could consider opening your mind to the possibility that the most appropriate solution to your situation may not be one you particularly like at first.

The solution is always going to be insulation + ventilation. You claim your house is well insulated, which leaves ventilation. So put an extractor fan (activated by the light switch and with a 15 minute timer) in each bathroom and in the kitchen. They cost about €40 in Screwfix last time I got one, and DIY installation is possible. That'll solve about 60% of your ventilation issue. Using the tumble dryer (vented outside or condensor) will solve another 25% (yes I'm pulling those numbers out of my @rse, but you get my point). You can probably live with whatever's left over.

C. Eastwood

https://www.boards.ie/discussion/comment/120106945#Comment_120106945

ShedHead

Brilliant explanation.

You forgot to add to the €450 Consolation (Salesman) Fee - for another few hundred € OR a few grand, for their products.

Also when I explain drying clothes in rads to families- I’m usually told that the Mother and Grandmother always did it.

I cannot understand how they charge €450 for a Report on Condensation.

I have already explained the cause of the condensation on 12-1-23@ 8.18 pm above, in relation to the 25 year old house.

It will be a generic Report with a many photos of the Condensation Mould and lots of recommendations to spend lots of money to buy their products.

What a waste of money - that could be better spent - as you have outlined above.

C. Eastwood

https://www.boards.ie/discussion/comment/120099265#Comment_120099265

You do not need to get an independent survey on your house.

It is a waste of money for your 25 year old insulated house.

Use the €450 to install an extra 200 mm of insulation in your attic.

I have already outlined how to reduce the Steam/ Moisture in your house.

Also when you get up in the morning, before leaving the bedroom- open the window and then shut the bedroom door behind you. Close the window after 1 hour or more.

Can you get Trickle vents fitted to your window frames. The outside grill of a trickle vent faces downwards. Whereas the outside grill of a wall vent faces the wind.

Each habitable room should have approximately 6,500 mm2 of permanent ventilation. So install trickle vents of this area in each room. These vents can be shut off from inside.

Your house is approximately 25 years old and you stated that there was 50 mm of Aeroboard in the cavity and that you got the cavity filled 10 years ago.

An uninsulated Cavity Constructed wall will have a U Value of approx 2.1 Watts / M2/degC/hour.

The 50 mm of Aeroboard in your house would have given a U Value of approx 0.52 W/M2/degC/hr.

Filling the Cavity in your house reduced the heat loss in the walls to an approx U Value of 0.30 W/M2/degC/hr.

That is a brilliant very low U Value.

Therefore the Insulation in the wall is Perfect. No need to add anymore insulation.

You said your ceiling insulation is approx 100 mm thick.

This will give a heat loss - U Value of approx 0.28 W/M2/degC/hr

With the above insulation and U Values - if you had sufficient Ventilation- you should not have any Surface Condensation in your house. - Provided you reduce the Steam and moisture as I outlined on this post recently.

If you have a lack of ventilation in your bedrooms - it will cause mould growth behind the bed headboard, and mould growth behind the curtains, and on the clothes and leather in the Wardrobes and this will create a stale musty Odour.

If you add another 200 mm of insulation to the ceiling it will reduce the U Value to approx 0.14 W/M2/degC/hr.

This would reduce the present heat lost through the ceiling by half.

Your house will be perfectly insulated.

If you need an explanation of heat loss calculations by U Values - let me know - and I will explain it here.

I would not install a Mechanical Heat Exchanger in my house. It will be very expensive and requires electricity and it has filters, and creates structure borne vibrations sound - and you do not need it.

Open windows and wall / trickle vents provides Free Fresh Air.

If wet clothes are dried on radiators- the water in the clothes vanishes in to thin air, and will subsequently reappear as water on windows and walls and clothing etc.

Calahonda52

Clint,

Lots of good stuff in that post.

A few comments

Each habitable room should have approximately 6,500 mm2 of permanent ventilation. So install trickle vents of this area in each room. These vents can be shut off from inside.

If closable then not permanent, take your pick.

Also when you get up in the morning, before leaving the bedroom- open the window and then shut the bedroom door behind you. Close the window after 1 hour or more.

By and large impractical for most folk, especially the OP

I would not install a Mechanical Heat Exchanger in my house. It will be very expensive and requires electricity and it has filters, and creates structure borne vibrations sound - and you do not need it. 

Most MVHRs are c 90% efficient and the quality of the air in houses with them, when designed, installed, commissioned, installed and maintained properly is vastly superior to what passes for free air these days.

You are being a little harsh on MVHR

C. Eastwood

https://www.boards.ie/discussion/comment/120111118#Comment_120111118

Calahonda52

Thank you for your wonderful reply and nice comment.

You have raised very good points here, and I will reply to same below.

You commented on 3 topics and I will reply to the first 2 point here.

Your comment in relation to Ventilation was as follows:-

________

• A few comments
• Each habitable room should have approximately 6,500 mm2 of permanent ventilation.
• So install trickle vents of this area in each room. These vents can be shut off from inside.

If closable then not permanent, take your pick.

_________

I cannot pick Permanent or Closable.

The Technical Guidance Document of the Building Regulations states that the background ventilation to habitable rooms must be permanent.

The 5 purposes of the Building Regulations (BR) are as follows:- Health, Welfare and Safety of persons, Conservation of Fuel and Energy, and access for people with disabilities.

The BR should be complied with.

However, I have reservations about some of BR in relation to the 5 purposes of the BR.

I will give 1 example of this:- The BR specify that only 1 Cold Tap in the Kitchen Sink - in the dwelling house is supplied directly from the Local Authority Watermain (with potable water). There are reasons for this but I have reservations with this BR and therefore all Cold Water Taps in my house are fed from the LA Water Mains.

The BR specifies that all other Cold Taps are supplied with cold water from the open Cold Water Storage Tank - which is usually located in the Attic Void.

Having inspected many of these tanks in the Attics - some of these Storage Tanks contain the remains of Rodents and Birds, and insects, decayed or partially decomposed.

People should be warned to never drink out of any Bathroom Wash Hand Basin Taps as it poses a health risk.

All I can do in relation to this is to instruct people - only drink water from the Kitchen Sink Cold Water Tap and Never drink water from any other taps in the house.

______________

Now in relation to background ventilation:-

The BR require permanent background ventilation.

The Building Regulations became operational on 1 June 1992, so many houses built before this date do not have external vents.

All the window frame trickle vents I’ve seen are closable.

Most persons prefer to have a choice with closable vents.

In my house, when Bedrooms are not being used by persons in Cold Weather, I completely block the background vents as there is no moisture being generated in these rooms. I would set the radiators in these rooms to approximately 10 degC to prevent condensation, and therefore the open vent here would lead to heat loss, which would not be in compliance with the BR purpose of Conservation of Energy and Fuel.

BR are black and white with grey areas???

Therefore if a habitable bedroom is unoccupied then no moisture is produced within the room (assuming no wet clothing on the rads).

_______________________

Calahonda52

Your second comment is as follows:-

• Also when you get up in the morning, before leaving the bedroom- open the window and then shut the bedroom door behind you. Close the window after 1 hour or more.
• By and large impractical for most folk, especially the OP

_____________________

You are correct that this may be impractical for many people.

The BR requires that each habitable room must have an openable window for purge ventilation, which should be at least 1/20th of the floor area of the room.

The average human exhales 0.35 L of water each day. The amount varies with air temperature, relative humidity, and level of activity, so the range is probably 0.3 L to 0.45 L per day.

However, an average human exhales 0.35 L of water each day. Therefore, 2 Adults produce approx 0.25 L in 8 hour which is a large amount of moisture in a Bedroom, and it is best to open the purge window for rapid ventilation for at least some periods of time each day.

Also Bacteriologists and Immunologists advised persons to open windows during the Covid outbreak to help reduce the possibility of getting infected with airborne Covid.

So open purge ventilation windows for some period of time during the day to reduce the moisture and to help eliminate Surface Condensation

C. Eastwood

https://www.boards.ie/discussion/comment/120111118#Comment_120111118

Calahonda50

Replying to your third comment below:-

Most MVHRs are c 90% efficient and the quality of the air in houses with them, when designed, installed, commissioned, installed and maintained properly is vastly superior to what passes for free air these days.

You are being a little harsh on MVHR

_________________

No I do not believe I’m being harsh.

You have a few problematic words in your above comment

1. Most ???????
2. 90%
3. When …………..Properly.
4. etc.

My house has free permanent ventilation and purge window ventilation. We have 100% perfect free air ventilation all the time, with no filters, no noise, and it uses Zero electricity.

I understand that we must heat the incoming air up a few degrees a few days as we live in Ireland.

An expert giving a lecture on MVHRs was asked a question about people changing Filters. The expert said that with these systems / there is Installation, Maintenance and Repairs. He said that most Irish people only do - Installation and Repair and added - most filters in these systems will only be charged when the system breaks down.

MicktheMan

https://www.boards.ie/discussion/comment/120117600#Comment_120117600

My house has free permanent ventilation and purge window ventilation. We have 100% perfect free air ventilation all the time, with no filters, no noise, and it uses Zero electricity.

I understand that we must heat the incoming air up a few degrees a few days as we live in Ireland.

Hmmm, so I guess then you don't have a fridge in your house either (or dishwasher, washing machine, clothes dryer or vacuum cleaner .. the list goes on) ....

An expert giving a lecture on MVHRs was asked a question about people changing Filters. The expert said that with these systems / there is Installation, Maintenance and Repairs. He said that most Irish people only do - Installation and Repair and added - most filters in these systems will only be charged when the system breaks down.

.... or indeed a car?

After all you don't actually need these pesky modern conveniences, they are costly to buy and they all cost money to run.

raclle

https://www.boards.ie/discussion/comment/120099299#Comment_120099299

Bought one before xmas and been a real game changer.