Black mould in light straw clay wall insulation

Hi, I am currently having a 12cm layer of a light straw/clay insulation put around the inside of my exterior wall in a new house. The exterior wall is made of the hollow baked clay bricks common in Spain/Portugal. I went down recently and all the walls that have been done are completely covered in black mould. This worries me a lot as I am very allergic to black mould and as I was only intending to cap with a permeable clay or lime layer, I do not want it coming through and being forever in my house. I already have a terrible chest just from working in the house for a couple of days. All the research I've done seems to say that this kind of inslation should suppress mould not cause it!

Do I need to have it all pulled off again? It would be better for me to have it taken off now whilst only half done than paying to have it all done and then finding it is forever mouldy behind cupboards and in the kitchen/bathroom etc.

I'd really appreciate advice from people with experience.

Read the workers the riot act and tell them you have no intention to pay for moldy work. Take pictures. If you wind up in court with this builder, show the judge the photos and he may throw the builder in jail as a public health menace. This is not just substandard work, this is potentially dangerous work.

Thankyou for your reply.

The person doing it said "it always does that but that it disappears when it's dry and isn't a problem". After trying to get rid of mould several time in various houses I find this very hard to believe as in my experience, once it is in a permeable material it is there forever! I appreciate that once it is dry it shouldn't grow but there is ALWAYS some moisture in a house, especially the kitchen and bathroom.

And black mould is so dangerous it really worries me that it could come out.

If "it always does that", then he needs to learn better methods. Like opening all the doors and windows when he is working and putting a high velocity fan in one of them. Get that air exchange going. If he did that, it would dry like it should, before it has time to grow black mold.