Mould and damp in attic space

I think I found the source.

The pipe brings fresh air up from the soffit, but just underneath it you can see a silver insulated MHRV duct. Out of picture there is about a 1 foot length that goes down into the bathroom that is not insulated. Where the duct penetrates the roof is poorly sealed. There is a bit of spray foam but I can see gaps. It's a very hard area to access as it's right in the eaves, but we are looking at remediation to ensure warm/moist air ain't causing problems!!

Yeah I guess his thinking was it's death by 1000 small cuts, but he didn't spend hours rooting through the soffits to find the smoking gun.

The pipes likely need to be cut back, as well as trying to prevent the warm air ingress. There is talk of ridge vents also.

So the steps to remedy.

Builder built an insulated hood for the stairs. There is an airtight seal where the hatch door meets frame, so this is just to up the U value in this area compared to rest of the roof.

We installed soffit vents to ensure in insulation was not restricting airflow.

Finally all pipes for ventilation system were insulated. The attic has dried out since the first incident. Hoping with these upgrades we are all set to for coming cold snap 🤞

It didn't really, So at its worst, it cleared in about 24 hours. Granted the temp rose and the wind picked up. Its a breezy attic, so while it could likely be improved, i just think based on my post above there is a defect that u would likely need a localized fan to deal with!

MHRV system is clearing the shower rooms. I mean there is condensation, but its completely gone within 15 - 30 minutes.

Issue would be its then expelled back into my freezing cold attic via the pipe above 😂

Yes it does. So if we take the ensuite there is obviously an extract vent. Just outside in our main room then there is an intake pipe. None of the doors and flush, and they would not be closed for long either way.

Based on what u said above, if it takes 15 - 20 minutes for the condensation to clear, imagine a bath or something at the same time in the main bathroom, im guessing you would get the temp in that pipe up for a prolonged period of time? This coupled with the humid air in the attic space would lead to condensation forming : this is my take.

OK, I understand what you are saying. I know the MHRV lad adjusted the modes as were were complaining of noise at night, and I noticed since then that the Purge was only operating at around 40%, when it used to be more like 80%.

I will have to check.

Nah its not happening in my case, it is dripping and mold has then grown.

I'm chatting to architect later, who has said tile vents will likely be required to increase ventilation, in addition to squashing the obvious defects.

It's possible, I don't know how to check/confirm that everything I think is mold is mold!!

I know that the ventilation is definitely not enough as I can see the drips, so clear course of action there to be taken

Appreciate all the feedback so far folks, marking progress learning and hopefully going to get sh1t fixed soon.