Please help!

daisyrose

Thank you everyone for your help.
The 100% humidity yesterday was outside courtesy of Google, probably not that accurate. This morning indoors the dehumidifier read 90%. We have a smaller one and a tiny one which probably isn't much use and I stopped using them all day last year because it seemed the mould problem was worse when I did. Doesn't seem right does it? I have never measured how much water they collect.

We don't seem to have any underlying problem, we looked at that first. It's probably more to do with the weather. There is always high humidity and washing left out in the sun stays damp sometimes. I worry that opening windows will let more humidity in especially on damp days. I have tried doors and windows open and closed and it seemed to be better with windows and doors closed which doesn't make sense.

The heating which if used is usually on for 3 to 4 hours at night but only when it's very cold. It was used for about an hour in the mornings when We had very bad weather. We find heating too dry, maybe that's why we had less mould in other rooms. We use the heating manually as and when required, only in the evening and if the temperature is about 14°or below in doors. The temperature is set at 16° max

We do have a log burner but we only use that at night when the heating is off and it gets chilly. We always use kiln dried wood. 
Could our problems be a temperature thing?

So I need some zinsser and got confused by the choice on the website and now there is 123 bin. A lot of them seem glossy. Do any have a Matt finish that covers the stains and stops the mould or do I paint something like dulux as a final coat?

 If there was a self application so I didn't have to do it that would be brilliant but I expect that is asking too much.
Thanks everyone.

housebuyer143

daisyrose said:

Thank you everyone for your help.
The 100% humidity yesterday was outside courtesy of Google, probably not that accurate. This morning indoors the dehumidifier read 90%. We have a smaller one and a tiny one which probably isn't much use and I stopped using them all day last year because it seemed the mould problem was worse when I did. Doesn't seem right does it? I have never measured how much water they collect.

We don't seem to have any underlying problem, we looked at that first. It's probably more to do with the weather. There is always high humidity and washing left out in the sun stays damp sometimes. I worry that opening windows will let more humidity in especially on damp days. I have tried doors and windows open and closed and it seemed to be better with windows and doors closed which doesn't make sense.

The heating which if used is usually on for 3 to 4 hours at night but only when it's very cold. It was used for about an hour in the mornings when We had very bad weather. We find heating too dry, maybe that's why we had less mould in other rooms. We use the heating manually as and when required, only in the evening and if the temperature is about 14°or below in doors. The temperature is set at 16° max

We do have a log burner but we only use that at night when the heating is off and it gets chilly. We always use kiln dried wood. 
Could our problems be a temperature thing?

So I need some zinsser and got confused by the choice on the website and now there is 123 bin. A lot of them seem glossy. Do any have a Matt finish that covers the stains and stops the mould or do I paint something like dulux as a final coat?

 If there was a self application so I didn't have to do it that would be brilliant but I expect that is asking too much.
Thanks everyone.

I found that humidity should be about 60 to stop the mould but also not make it too dry. We had a meaco 123  dehumidifier (was about £120) and it used to have a humidity rating on it and collect a lot of water. Too much water vapour in the house along with a badly insulated roof (domer for you) and you will get mould. Should only need it in the colder months though.

This is the paint I used. Unfortunately it's all shiny owing to the stain blocking element but you can go over it with normal paint and it's covers fine 👍

https://www.screwfix.com/p/zinsser-b-i-n-shellac-based-primer-sealer-1ltr/29661

markin

They can't make a problem worse, If they were pulling water they were helping and just couldn't cope with the huge amount of water in the room.

Now it will take weeks and months to dry out again. 14c-18c at 60+% humidity will be a mould factory!

_Sam_

daisyrose said:

Thank you everyone for your help.
The 100% humidity yesterday was outside courtesy of Google, probably not that accurate. This morning indoors the dehumidifier read 90%. We have a smaller one and a tiny one which probably isn't much use and I stopped using them all day last year because it seemed the mould problem was worse when I did. Doesn't seem right does it? I have never measured how much water they collect.

The indoor humidity of 90% is a lot. Do you have any wardrobes, bookcases, anything against the walls? Have a look behind those and check the condition of the walls. A friend was decorating their bedroom and they moved the wardrobe only to discover a black wall behind absolutely full of mould that they had been breathing for years - and they never even suspected they had the mould problem until they moved that wardrobe.

I'd suggest to buy a good quality dehumidifier. Our's is a top range and was only £250, they aren't that expensive especially compared to the benefit they can provide. It will have a water tank collector underneath, which you have to empty everyday as it gets full of water.

When you say you've "never measured how much water they collect" it makes me think you don't have a proper dehumidifier, else you'd be emptying that water tank all the time and would surely know how much water you were getting..

[Deleted User]

Agree with the above.
100% indoors indicates a very low room temperature @daisyrose and keeping doors closed will restrict that airflow more.

The Ebac dehumidifier i have shows exactly how many litres is being collected each day - however, i've now raised the temperature in the 1 room i use it in and no longer get humidity higher than 49% so don't use it !

daisyrose

So the temperature is too low? That could be a problem for oh, he doesn't like heat. The largest dehumidifier we have cost around £120 and needs to be emptied almost daily depending how long it's been on. The others are too small to make much of a difference  but every dehumidifier will help.  
I do pull furniture away from walls to check behind and there is one wardrobe where I found a black mouldy wall behind it. Now I don't push furniture close to walls I leave a gap for airflow.
Do you only use the dehumidifier in one room or move it around rooms and how do you keep the humidity under 50% after it is switched off or do you use the dehumidifier all day?

markin

14c should be ok, most start to struggle below 8c. You keep it on 24/7 until the water it collects becomes not worth it, then you can run it once a day to maintain.

A corridor is often the best place as it will draw air from all rooms in the house, but you need to concentrate on the problem room for now.

You do have kitchen and bathroom extractors don't you?

GDB2222

Outside the house in this country, when the weather is damp, humidity could easily reach close to 100%. That’s completely normal.

Most people heat their homes more than you do. Warm air can hold much more moisture, so the humidity drops if you heat the house more.

daisyrose

 It sounds to me that it is the low temperatures here that is most likely the cause of the problem and possibly there could be an issue with insulation in parts of the roof that we have no access to.
Today I put the dehumidifier in the hall and left the room doors open. The humidity was 70% so I left it running all morning. Humidity reached 49% so it went off for 45 minutes. I turned it on again and humidity was back at 69%.
Thank you Marlin your advice on how to use it properly is a great help. No extractor fans, the windows are always opened wide when showering and cooking.
Thank you everyone, I feel more positive about tackling the mould now than I did when I first posted the question.