Dampness/Mould in bedroom

thestar

Hi all,

I'm treating dampness/mould in a bedroom. I have a dehumidifier which I am using first. How long should I use this for? I had it on yesterday for approximately six hours and I got just under a cup of water gathered in tank?

57% is the reading coming up on the machine, possibly gonna leave it on until its down to 40% or should it be left on until its not collecting anymore water?

After the dehumidifier I plan to clean the mould, treat it with specific paint and then paint over again with normal paint?

Any advice/tips would be appreciated,

Thanks

Alkers

Are there vents in the room? Heating? Windows? Drying clothes? Are you sleeping in the room? Is it insulated?

Using a dehumidifier is like using a bucket to fix a leak, you need to sort out the cause

PCros

thestar wrote: »

Hi all,
57% is the reading coming up on the machine, possibly gonna leave it on until its down to 40% or should it be left on until its not collecting anymore water?

57% is fine in Ireland - if you bring it down to 40% you may find the air too dry, chapped lips and skin problems could occur.

Are the windows in a bad state because you would be looking at 70% and over for mold to even make an appearance.

olestoepoke

I worked in a house in the US years ago where they had a mould problem. The owners called in specialist to kill the mould. They arrived in disposable overalls heavy gloves and respirators etc. I spoke to one of the workers outside and out of the corner of his mouth her told me that raw bleach kills the mould on non porous surfaces and for wooden beams etc or more porous materials they soak it in vinegar. They charged the lady quite a hefty sum for something you could easily do yourself. I agree with the previous poster that you need to deal with the root cause. Leaky roof? not enough ventilation? kill it with bleach and vinegar then sort out why its happening or it'll just return.

thestar

I can't definitely say the cause of it. Its rented accommodation. There is a vent in the room but seemingly the last person in the room didn't open a window.

Maybe this is the cause but I cant be sure

thestar

Alkers wrote: »

Are there vents in the room? Heating? Windows? Drying clothes? Are you sleeping in the room? Is it insulated?

Using a dehumidifier is like using a bucket to fix a leak, you need to sort out the cause

There is a vent in the room, a radiator, I haven't slept in the room yet but thats the plan. No there wouldn't be clothes being dried.

loyatemu

it's a combination of ventilation, humidity and temperature. Good video explanation here:

https://www.youtube.com/watch?v=TIDb-pdOnXM

Mango Joe

Hi there - I unfortunately know too much about mould due to having issues at home here and there - Also the below isn't me being opinionated or full of ***** - Its mainly stuff I learned from reading on here and other places - I'm open to correction or other advice too & always grateful for it.

There's some very good advice above - Basically you could dehumidify, clear mould stains and redecorate every day for the rest of your life but if you don't sort out the root issue of wet air condensing on cold surfaces you will perpetually have mould.

I read on here years ago and it stayed with me - You don't "clean mould", you have to kill it...

1 part ordinary Supermarket bleach to 3 parts water is fine. Put it in a old windolene spray bottle and be sure to wear gloves, glasses and a mask of some sort - open all windows, protect your health. Wipe any run-off drips with a cloth to contain it and avoid streaking walls etc.

The good news is the bleach will actually clear a lot of the staining too - Sometimes completely, keep doing it and you'll get back to a white ceiling that might only need one quick coat of paint.

Humidifiers don't work at all well in the cold, you'll need to lash the heat up and you might find it collecting more than the odd cup of water you've mentioned. Alternatively the room isn't damp anymore since the last tenant left as you're opening windows, not drying clothes inside etc.

Look at the mould stained area for anything holding water, in my house there was a very slight gap in places where the ceiling met the walls and it was holding enough damp for mould to get a foothold and spread outwards.

A plastered ceiling should ideally have been sealed on day one before regular painting - none of mine were as we were just clueless back then and wanted to get a quick coat of paint on and move forward.

AFAIK a good tip here it to mix regular PVA glue from Mr. Price with 3 parts water and paint it on like an undercoat, it soaks in, seals the area and gives a less porous surface for your final coat of paint then. You could spend a fortune on Zinsser Peel Stop or similar products but as far as I can tell from how they smell they're just PVA glue with water anyhow.

* Someone please correct me if any of this is poor advice or needs changing!

** See if you can inspect the ductwork behind this vent - They're commonly blocked due for noise or heat-saving reasons, people stuff crap into them, you should feel a slight draft of air if you hold you hand up to them.

bluelamp

thestar wrote: »

Hi all,

I'm treating dampness/mould in a bedroom. I have a dehumidifier which I am using first. How long should I use this for? I had it on yesterday for approximately six hours and I got just under a cup of water gathered in tank?

57% is the reading coming up on the machine, possibly gonna leave it on until its down to 40% or should it be left on until its not collecting anymore water?

After the dehumidifier I plan to clean the mould, treat it with specific paint and then paint over again with normal paint?

Any advice/tips would be appreciated,

Thanks

Hopefully it was the previous tenants way of living that caused it rather than an issue with the building.

Make sure the vent isn't blocked, lots of people pull off the plastic cover and shove a towel in there.

This paint is fantastic at keeping the mould away:

https://www.screwfix.ie/p/zinsser-self-priming-paint-satin-white-2-5ltr/62096

Or if you want to paint a different colour you could buy one of the zinsser primers (the red shellac one is best) and paint over it.

I'd leave the dehumidifier running a couple of more days, bleach the mould, then paint.

If it comes back, there's a bigger issue.

thestar

As a matter of interest, could having a window closed for weeks on end cause mould/dampness?

Thanks for all of the replies

PCros

Yes, if the window has been closed for a prolonged time with no heating it is a huge factor.

Wet, damp weather, like we have here in Ireland combined with closed windows and no ventilation will cause it.

olestoepoke

Also check the vent inside and out and make sure its not blocked. People sometimes stuff them to keep drafts out and layers of paint outside can also block them.

PCros

olestoepoke wrote: »

People sometimes stuff them to keep drafts out and layers of paint outside can also block them.

This is actually a great point and possibly not even thought of in a lot of cases.

I only noticed this on 2 of my vents the other day after getting the exterior painted during the summer.

Alkers

thestar wrote: »

As a matter of interest, could having a window closed for weeks on end cause mould/dampness?

Thanks for all of the replies

Yes absolutely, particularly if there was no heating on.

This would probably be a best case outcome for you as it means that if you heat this room and ventilate it properly along with normal use, you probably won't have the problem reoccur once you deal with the mould and damp thats there now.

Gorey3

https://www.boards.ie/discussion/2058135350/dampness-mould-in-bedroom

Hi thestar where did you get the humidifier? Do you rent them?