Dampness causing allergies? Unlikely to be mould.

[lilyflower1803]

Hello!👋

We bought and renovated a very mouldy flat and moved it in August 2023. We stripped back the walls to exposed brick and replastered using waterproofing (allegedly!). Over winter we have several damp spots which are being investigated and hardly any mould yet 🤞 (a tiny bit in the bathroom that we keep on top of). We have now two dehumidifiers, but without them we struggle to get humidity down from at about 60-75 %. Even then, as soon as we turn them off, humidity goes straight back up- it’s a real battle.

Since moving in in August- when the flat was dry (!), both my partner and I have struggled with allergy like symptoms, itchy eyes on wake up, irritated nose and eczema (for me).

I’m quite allergic and have lots of airborne allergies including dust mites so this isn’t unusual for me when living in a new place, plus it was summer when moving in and pollen was high. However over time/winter it is now affecting us even worse and has given my toddler very sore eczema and I haven't been able to shift my eczema with steroids so it is clear something is really bothering us. We have thought of mould, left over builders dust, dust mites being left on old furniture/cleaned the radiators and carpet fibres from fitting!

Surely it cannot be any mould as we got rid of it all and replastered? Any ideas/advice? Not expecting miracles but just curious to see if anyone has suffered with similar.

Ps our dehumidifier has an air purifier in it!

It might be mould. Usually the advice is not to use waterproofing plaster but to use breathable plaster so that any moisture coming into the bricks from outside or below evaporates? If you waterproof plaster the bricks, you often end up trapping condensing moisture between the bricks and the plaster and then mould sometimes grows behind the plaster. (Warm internal plaster meets cold external wet brick)

What sort of ventilation do you have? With your flat being like a sealed plastic tub, you would need to have an open window and extractor fans too? Does your dehumidifier have an air filter? They often push out dust laden air as they work if they don’t come with a filter.

You could try getting an air filter and ventilating the flat better.

Sorry, don’t know how I missed your ps on the air purifier. So, did you recently replace the filter? If you’ve been running it often since August, it may need a new filter.

Hi! Thank you for your reply. We got told to waterproof it but totally get what you're saying. Think it is a lose-lose situation as there was water coming through the expose brick anyway. Can mould penetrate the plaster if it's behind it? The waterproofing hasn't worked anyway as our walls have salt and are wet 😅

We use two dehumidifier's, ones a 10l and ones a 20. We try to ventilate the flat as much as possible by opening our windows and using the ventilation latches. We keep our bathroom windows wide open after showers etc.

We did think maybe the air being blown out the dehumidifier was causing it, especially as we used one of them when renovating. But we have cleared the filters etc well.

We find the bedroom the worst for our symptoms and that's where most of the damp is so it checks out. What could we do if there is mould on the other side? Fix the external issue and then replaster?

Hi! No air purifier/second dehumidifier is a new addition over the last couple weeks :)

How is water coming through the bricks? Ordinary rain shouldn't soak through bricks all the way to the inside. You need to find out why the water is coming through. It's no good treating the inside of the wall without rectifying the cause.

Should add, both dehumidifiers have a filter, one being a HEPA, the other just a big standard one I think

Hard to say if the plaster was waterproofed or not from what you’ve said. Initially, I was thinking the damp spots was water condensing behind the plaster and then running down the back of it.

Now I’m not so sure you don’t have water intrusion from outside the flat. Has everything been checked insofar as plumbing above and beside your flat? Or the roof if you are top flat? What is above your bedroom? Is there a water wall in the bedroom- as in does it share a wall with kitchen/bathroom where there are any taps or drains off that wall?

Have the windows been checked for leaks around the frames?

Yep, aware of that. The management company are investigating that as we do not have authority to alter the external walls so we quite simply can only do what we can from the inside (what we own). We thought we solved the issue by replacing an air brick that had been installed incorrectly but unfortunately didn't work.

They have done some investigations and there is no sign of any wet cavity wall insulation or bridging, so it is a bit of a mystery at the moment...

The water doesn’t come through the bricks when you have one side bare to exterior and inside waterproofed. What you get is condensation between the cold brick and warm plaster if the plaster doesn’t breathe.

Hmm. Any evidence of air bricks being removed by the prior owners? You said flat was mouldy when you bought it. It is possible someone has blocked or removed needed air bricks.

The room doesn't adjoin to any plumbing and the flats are like carbon copies of each other so it's the same set up upstairs ( we are ground floor. Our problem area in the bedroom is on the wall to the right of our window, ranging from top to the bottom. the wall adjacent to that links to our living room. It is so bizarre as there are random points on the walls where bricks are getting sodden. They need to redo some of the pointing on the property but there is definitely something else going on.

I know right, hard to believe it was waterproofed at all, if it was it didn't work!

What about carpets? Are you on the original carpet? It could be that.

It is so bizarre as there are random points on the walls where bricks are getting sodden.

Have you looked from outside? Any gutter down pipes running near where your wall is wet? A leaking down pipe ?

Could upstairs flat’s bedroom window be leaking?

@Cherryon we only had one air brick on this wall at the top, which was where there was and is damp on the wall. We thought water was coming in as this side of the flat gets lots of prevailing weather and it didn't have another airbrick to ventilate and dry (as there was only one) making it wet and sodden- but the wall inside is supposedly dry. Apparently the airbricks have been tampered with in the past but I can't remember what the guy told me he knew happened .

We replaced the carpets, and I originally wanted wooden floors due to known allergies but we opted for anti allergy carpets in the end for warmth 🤣

Upstairs window is a possiblity. The windows in these flats have some known issues which we have in ours too which doesn't help. See attached photo. Corners of the windows are a bit drafty. Most people have had to replace them to stop this from happening, but is a minor issue in the grand scheme of things when other internal walls are sodden wet 😅

Also no guttering or pipework in the problem area!

The other areas that are wet in other locations in the flat have obvious reasoning as something is causing it on the external wall where things have been drilled in.

Except that the window in your photo is clearly letting water in and that is making walls wet. Thats a known damp issue you could fix and may make any other issues causing the rest of the damp easier to identify.

That window is also fogged up with horrendous condensation. You need to wipe or vacuum the inside condensation off all your windows. If it’s your window…is it a neighbour?

@Cherryon true, definitely a positive way to look at it. But I suppose what I'm saying is the internal wall on that window is not wet yet, whereas some of the walls like the bedroom one the pain has flaked off and is damaged and wet.

Unfortunately I don't think any of these things are interlinked much/no common causation so yes, a problem to tackle one by one I think

Luckily it's not condensation! It's privacy glass :) we have a window vac and thankfully don't get too much condensation- I thank the dehumidifiers!

The bedroom damp starts at the top of the wall which means the water is running down from above. You see your photo- that is how far out a leaky window can make a wall wet under it. I’d check the bedroom window in the flat above you. If it is causing that damp, then their homeowners insurance or the building insurance (if the building exterior is covered by service charges) should be paying to fix the damp in your bedroom because the source of the damp is outside your flat and originates due to poor maintenance of someone else’s property.

Phew! My eyes deceived me in a good way.

@Cherryon I will have a look tomorrow and update! You are right. Hopefully that is the identifiable cause! Yes it should be covered under insurance.

@Cherryon though you should see the condensation in some of the other flats around here 😬! Some horrors to be seen! 😅