Question on bathroom renovation

Hi,

I'm getting my basement renovated and the location where the bathroom will go has a valve in the ceiling which switches the water on/off for the valve outside of the house. I was planning to have an access hatch installed in the ceiling in the bathroom, in order to access the switch. However, I'm not sure if the humidity in the washroom from when someone takes a hot shower would be an issue as the steam may rise up and through the hatch?

Appreciate any advice.

Thanks!