Help needed 1930s excouncil house with toxic mould problem

[JaneWard]

Hello - for many years we have had a problem with mycotoxins in our house. Firstly it was due to conservatory leak, then when we discovered it was toxic mould it was under the bath and in the kitchen - that was 2019 and the whole family were quite ill - i had my daughter tested and she had high levels of mycotoxins in her body consistent with penicilium and aspergillus moulds. When we found the actual mould (as nothing was visible and we had to move out for 8 months while we had the house ripped apart to find it) it was about 30cm x 10cm and behind a pipe cover in the kitchen - unbelievable how something that big could affect us and all our furniture / books / clothes so badly.

Now we have another issue with hidden mould - we have an 1935 build ex-council house with damaged and blown external render (we are getting Never Paint again to repair this for us) and i am not sure if the mould is behind the render or where it is. This year in particular there is a really bad musty smell both downstairs and in the front bedrooms - there is no mould on the walls and we even took off some of the plaster and took a brick out upstairs which showed as damp - still no mould but the smell of the bricks is awful - a kind of sharp smell?

The back of the house seems OK and i am able to sleep in the back bedroom but cannot sleep in our main bedroom due to the mycotoxin symptoms again. Upstairs there is no cavity in the wall - there are 2 layers of bricks which seem to be very close together - damp meter is show only some of the exposed bricks as wet - others are not too bad - the rest of the wall has wall rock wallpaper and doesnt show as damp at all.
Downstairs there is a cavity and we have just had the cavity wall insulation removed - we were told it was wool and was wet and then upon removal it turns out it was foam and was completely dry!
Looking at other houses in the street - those that have not been fully rendered have some kind of brick extending out between first and second floor (see pic) - the rendered ones dont and i was wondering if there was some kind of gap or if they removed the bricks to render and did some kind of damage? Our house is the fully rended and the brick on is another of the same build unrendered.

The chimney needs pointing and we have just also discovered wet bricks behind the wood burner!

The other thing that might be a contributing factor is that we have a radon sump fan outside of the front room - this doesnt smell mouldly though.

Has anyone got any suggestions as to where this mould could be and what could be happening in our house to cause this issue? I have searched and searched to see if i can find any similar issues to no avail. Thank you

 

[foxhole]

Rain down chimney will cause damp and mould , gutters blocked? Poor render with trap moisture causing damp problems .
Holes around pipework need sealing ( another damp source ) .
What condition is the roof and verges like?

 

[JaneWard]

Thank you - gutters have been cleaned so clear - definitely poor render - hoping that is the problem - yes holes around the pipework definitely need sealing as when we had the cavity wall insulation removed it all came in through those holes. Roof is fine - attic space is dry - we also have a PIV installed - not too long had fascia done so that should all be OK