Black Mould on Bathroom Ceiling

[chukwe]

We have Black Mould on the upstair bathroom ceiling. None on the downstairs bathroom. From time to time, I use Cilit Bang Black Mould Remover to clean it.

A Plumber who visited my house to fix our shower said I should use a "Stain Block" and "Anti Mould Paint" to treat it.

Is that the right course of action? I am not sure of the procedure of doing the Mould Treatment

[droopsnoot]

What's the ventilation like? I have similar issues, in my case it seems that a lack of ventilation is the main culprit as, other than the window and a badly-placed airbrick, mine has nothing, and it's too cold to leave the window open much.

[greygoose]

Do you have an extractor fan in the bathroom and does it work (or is there a window to open?)?

[chukwe]

droopsnoot said:

What's the ventilation like? I have similar issues, in my case it seems that a lack of ventilation is the main culprit as, other than the window and a badly-placed airbrick, mine has nothing, and it's too cold to leave the window open much.

I window is always open, but the mould always come back after spray treatment

[chukwe]

greygoose said:

Do you have an extractor fan in the bathroom and does it work (or is there a window to open?)?

No Extractor Fan. We moved into the house 3 years ago. I believe it's being a long term issue as it slightly affect the bedroom nearer to the bathroom

[Glosphil]

I have the same problem along the edge of the ceiling above the bath. There is an extractor fan that is left on for, at least, an hour after my wife has a bath (I use the shower in the en-suite).

Problem seemed to start after the old wooden framed narrow gap double-glazed window was replaced with modern uPVC window with a wider gap. Adding the extractor fan did not solve the problem. However there is no condensation staying on the window.

[chukwe]

Has anyone used Stain Block or/and Anti-Mould Paint to treat mould? Did it work?

[greygoose]

chukwe said:

greygoose said:

Do you have an extractor fan in the bathroom and does it work (or is there a window to open?)?

No Extractor Fan. We moved into the house 3 years ago. I believe it's being a long term issue as it slightly affect the bedroom nearer to the bathroom

Maybe have a check there isn't a water leak in the loft above that area if it is in both rooms.

[deckster]

chukwe said:

Has anyone used Stain Block or/and Anti-Mould Paint to treat mould? Did it work?

You don't get rid of mould by painting it. You do it by working out why it's happening and fixing it - in bathrooms, usually it's poor ventilation. If you don't already then chances are it will go away if you just leave a window open.

Fundamentally you need to change the conditions in the bathroom that allow mould to grow, not just cover over the symptoms.

[chukwe]

deckster said:

You don't get rid of mould by painting it. You do it by working out why it's happening and fixing it - in bathrooms, usually it's poor ventilation. If you don't already then chances are it will go away if you just leave a window open.

Fundamentally you need to change the conditions in the bathroom that allow mould to grow, not just cover over the symptoms.

Thanks. Any tradesman that deal with mould issues? 2 Plumbers that saw it couldn't work out the issue. That's why one of the plumbers recommend stain block

[malks222]

I had a bit of a mouldy ceiling above the shower enclosure in a previous bathroom (internal bathroom, no window, poor extractor fan) where the paint had started to flake off.

I scraped back the plaster, gave a good scrub clean where I could and repainted with ‘zinsser anti mould paint’. it worked great and no mould re-appeared. Ok it was a bit of a bodge/ temp fix, but it lasted a couple of years without issue until the bathroom was refurbed and better extraction installed

[Dr.Hellno]

Give it a good clean and let it dry, 2 coats of Zinsser B.I.N, 2 top coats of some anti mould paint.

[Pflanzgarten]

deckster said:

chukwe said:

Has anyone used Stain Block or/and Anti-Mould Paint to treat mould? Did it work?

You don't get rid of mould by painting it. You do it by working out why it's happening and fixing it - in bathrooms, usually it's poor ventilation. If you don't already then chances are it will go away if you just leave a window open.

Fundamentally you need to change the conditions in the bathroom that allow mould to grow, not just cover over the symptoms.

Not true.

Stain block and Zinser Anti Mould paint do work and you'd do well to use some mould killer before that as well. It's all very well going full piston heads and recommending some expensive mechanical heat exchanging ventilation as well as ripping out the bathroom and fitting insulated plasterboards...

But, in some cases you're just stuck with a poor performing building envelope that will cost £££ to change.

In the medium term, accepting you have a bit of a cold, damp bathroom and repainting your bathroom ceiling is enough for most people.

[Hondashark]

Bathrooms usually on external walls, have a crap towel radiator in and its the worst time of year.
Too cold to have the windows open properly yet not cold enough to have the heating on to help keep the bathrooms dry.

[ARHarh]

I have had mould growing in the very top corner of my bedroom for years. We would clean it off but it kept coming back after a few months in the winter. It was due to the wall being colder there than anywhere else, not easy to fix as just due to being in the prevailing wind on the side of a hill.

Anyhow, we painted over the affected area 2 years ago with this https://www.dulux.co.uk/en/products/dulux-easycare... then painted over that with the normal wall emulsion. Been no trace of mould since.

[dhutch]

Ventilation.
Insulation.
Heating.
HG Mould Spray.....

Lime plaster also helps but we dont like that any more because its 'old fashioned' and takes a bit longer to dry.

See also; Nuaire PIV
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[dhutch]

JRHartless said:

Thats basically nonsense, unless you're prepared to go to extremes of cleaning, heating, air circulating and/or dehumidifying.

It's almost inevitable you're going to get a few mould spots above a well used shower.

Which just points to poor design, in my book!

[chukwe]

As the bathroom is small, is it worth doing the ceiling painting myself or hire a professional painter? I've never painted before but good at DIY

[deckster]

JRHartless said:

Thats basically nonsense, unless you're prepared to go to extremes of cleaning, heating, air circulating and/or dehumidifying.

It's almost inevitable you're going to get a few mould spots above a well used shower.

My bathroom window is open 24/7 yet I still got a few faint mould spots above the shower (until I used anti-mould paint)

:shrug:

I wouldn't call ensuring that have good air circulation as being extreme, but each to their own. FWIW I don't have any mould in my bathroom and I would definitely not call it inevitable.

[ARHarh]

deckster said:

JRHartless said:

Thats basically nonsense, unless you're prepared to go to extremes of cleaning, heating, air circulating and/or dehumidifying.

It's almost inevitable you're going to get a few mould spots above a well used shower.

My bathroom window is open 24/7 yet I still got a few faint mould spots above the shower (until I used anti-mould paint)

:shrug:

I wouldn't call ensuring that have good air circulation as being extreme, but each to their own. FWIW I don't have any mould in my bathroom and I would definitely not call it inevitable.

As suggested good ventilation is not always the answer. In my bedroom we always sleep with the window open, and the window will be open 24/7 during the summer even if we are not at home. So you can't say it was not ventilated, yet we still had mould in the corner.