Mould has returned whats the next step ?

westcountrycat · Post by **westcountrycat** » Fri Oct 18, 2019 5:28 pm

Hi Rorschach, photos below, id appreciate your thoughts. Thanks :)
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Rorschach · Post by **Rorschach** » Fri Oct 18, 2019 5:45 pm

Ok give that the problems are all in the room on that corner I would expect you are suffering from the exposure to the elements making that wall cold.

Looking at your building it appears it might be a Wimpy no fines construction which does not have a cavity. Not a major issue as the concrete itself has a good insulation value but they can suffer from cold outside walls. That corner there is very exposed to wind and rain especially as there is a gable end.
I would also be taking a look at those cable penetrations, make sure a little bit of water isn't weeping in there.

The air brick at area 2 does that go into a cavity? (making me wrong about the construction) or does it go into a vent on the inside of the room? (with no cavity) If so that would be a terrible source of cold damp air in the winter.

westcountrycat · Post by **westcountrycat** » Sat Oct 19, 2019 2:50 pm

Rorschach, picture a above requested -answers to your other questions,

Yes it is upstairs and we have a shower room upstairs but we have an electric vent system which we use everytime we have a shower or bath. I don't ever hang wet clothes in the small room, but there are damp towels on a heated towel rail in the bathroom which is on the same floor.

There are four of us in a house.

I open the window pretty much everyday unless raining

There is occasional condensation on the window it is cold outside which i dry off

The door itself is never closed and usually wide open

It is the coldest room in the house but we have insulated behind the slope from in the roof, have new window and even insulated the porch area as much as possible.

It had a stair well bulk head in the room

Im a cold bean so the whole house is fairly warm day and night at least 17/18

We have thought about studding the wall to create an air gap but reluctant as the room is already small but ive got to the point where i'll try anything for my boy not to have a mouldy room :(

Thanks

westcountrycat · Post by **westcountrycat** » Sat Oct 19, 2019 2:55 pm

The airbrick goes from the outside all the way to the inside of the room and yes its flipping freezing, we have tried leaving it open for some years being paranoid about ventilation but found we had to block it up this year and overall the mould has been better not worse.

I'm not sure how i check whether it is in the cavity or not ?

One guy came round a few years ago ref cavity wall insulation and did a test on the owner floor and said we had already had it done, this must have been along time ago as we have been here for about 14 years.

Rorschach · Post by **Rorschach** » Sat Oct 19, 2019 4:09 pm

Those air bricks are such a stupid idea, I suppose back in the day when boiler and fires needed ventilation they were a good idea but in a modern house they are just letting cold wet air in.
How have you blocked it up, would be a good idea to make sure it is done properly and not letting a draught in. Any others in the house do the same.

Good to hear the mould is better. Don't worry about condensation and mould around the windows, that is normal, just keep the area cleaned regularly and remove moisture when you can, we have a window vac for that, works great.

Get yourself a cheap temp/hygrometer, I will link to one below. It will help you see how humid the house is. I suspect the mould is simply a combination of 4 people living in the house and some cold spots on the exposed areas causing that moisture to condense.

This was almost exactly the problem we had in our flat (2 people in a smaller space so same thing going on). The solution has been simple, all areas that were prone to mould were cleaned and painted with an anti mould paint (not expensive and just done as part of normal decorating). When the weather is fine we ventilate using the windows and when the weather is wet we keep the place sealed up as best we can and use a dehumidifier.
My sister also had similar issues, again solved by using anti mould paint on the affected areas and using a dehumidifier during the winter. A couple of hours a day is usually enough. Electricity cost for a years running is less than a takeaway but it saves me hours of cleaning and our house is much healthier and warmer as our heat isn't going out the window.
I think you should do the same, paint the affected areas and after checking with the hygrometer use a dehumidifier. They are not too expensive to run and during the winter they put out a bit of warmth too.

This is the hygrometer I use, very good value.
https://www.ebay.co.uk/itm/Digital-LCD- ... Sw6fVdSXtS

wine~o · Post by **wine~o** » Sat Oct 19, 2019 4:57 pm

Bleach the f3ck outta it, rinse, give it a coat of oil based undercoat and topcoat of your choice. Assuming the original damp issue has been resolved then you shouldn't need any more remedials for about 5 years...

Edit.

You might also want to look at summat like this https://bit.ly/2Bu5NXG

To replace the air brick.

westcountrycat · Post by **westcountrycat** » Sat Oct 19, 2019 8:26 pm

Thanks again Rorschach, have nought the humidity thermometer, whats an acceptable amount of hummidity ?

In terms of a humidifier, do i need a big one ? i've seem some smaller ones, as the rooms so small i don't want to take up too much playing room.

Rorschach · Post by **Rorschach** » Sat Oct 19, 2019 8:48 pm

Something around 70ish % is good to aim for in the winter in the UK, over 80% is when you will start to get problems.

Small dehumidifiers are very inefficient and won't remove enough moisture from the air. It's not just the room you want to dehumidify, it will be the whole house.
It is critical though that air leaks are closed up properly such as trickle vents or airbricks otherwise you will just be wasting your time.