Void behind skirting board on outside wall

[Spo_spo]

Hi All,


Looking for an advice.
We are in the procesd of replacing flooring in our new build (built 7 years ago) and after removing skirting boards, we noticed quite large holes to the void in that seems to go under the house of that make sense.

Both holes are on opposite sides of garden door, both on outside wall.
This is outside wall facing north and is suffering from damp and moldy spots around garden door frame.

Both wholes seems to be several inches wide and deep, we managed to pull out of them tiny bit of some sort of wool and it is very wet, we can also feel draft coming out of them.


I am attaching some pics and sort video.


Are these holes needed and if not, can I fill them with expanding foam? Or should they be filled in with other kind of insulation?

We're still within nhbc warranty but I'm not sure if this is something to worry about and if it's worth fighting warranty repair?


Thanks all!

 

[blup]

The wet insulation is a concern. Try to establish the cause of that.