New build - blue mould spots appearing

Eniledam

I got a garage conversion and small extension completed 2 weeks ago. The rooms haven't been fully plastered yet, only plasterboards. Over the past couple of days, blue mould spots have started appearing along the plasterboards adjacent to external walls - both at the front and back of the house - high and low. I contacted the builder immediately and sent him photos. His reply was it must be the clothes dryer, go ahead and plaster, nothing to worry about.

What would you suggest? Is there anybody independent I can get an opinion from?

I have people lined up to do some electrics, plastering etc., in 2 weeks time, so I need to get some urgent advice.

Thank you.

Bonzo Delaney

What ventilation is in the room
Is there heating in the room yet
Do yo notice condensation on the windows internal pane
Is there a clothes dryer in the room where is it vented too

Eniledam

Hi,

There is plenty of ventilation as property is only at first fit. There are big ventilation holes in both rooms where there is mould. There are no doors fitted yet. Yes there is a condensation dryer but absolutely no mould in that room. Rooms have been heated on timer. No condensation on the newly fitted windows or patio door.

Lumen

Is it possible that the plasterboard got wet before or during construction?

Eniledam

Thank you, that might explain it. I am hopeful it is just superficial. I have cleaned them all up now and fingers crossed it is sorted now.

selfbuild17

It’s not unusual to see some mold growth inside when plaster is drying out. The humidity in the building is bound to be high and you’re introducing a huge amount of moisture into the structure. Increase the ventilation and clean the mold down after it has dried out