are there paint application techniques/ details I need to know when painting in dry climate (northeast)?

Question

painting bathroom wall in winter. Air is very dry. 0% RH.

Answer 1

If the air is very dry the paint might dry too fast, making it hard for you to roll out a nice finish -- use a paint additive like Floetrol. It makes latex paint stay wet a little longer and go on smoother. The additive doesn't harm the look or quality of the paint if you follow the directions on how much to use.

Don't let the bathroom get steamy for the first couple of days after painting. I know this is hard, but take cooler showers, leave the door open, whatever you have to do. Humidity and condensation can make surfactants leach out of new paint and cause streaking. This is true anytime you paint a bathroom. If you've ever seen amber or light brown sticky drips on bathroom walls, that's what it is -- leaching.