How quickly must prefabricated houses be made weather-tight (roof on)??

[Byggtagen]

Our house arrived a few days ago. The walls were assembled and then the rafters. But then the builders simply went home even though there were several hours left of the workday. Always before, they have said that the house should be sealed after 2 days, roof on. But now it has been open for several days. I thought it was OK since it's sunny and nice weather, but last night there was a lot of moisture and fog... is there any danger?

 

[prototypen]

Moisture and fog are not so bad, but rain is worse. It's bad form not to cover with a tarpaulin or plastic.

Protte

 

[Matti_75]

There is a golden rule that says single-story house roofs on day one. Two-story house roofs on day two. Have built 8 prefab houses.