Painting a ceiling for seven hours is not advisable.
YP: 'Trimming in' means using a small brush to feather in the edges so that you can take the roller down between the beam work and not splatter paint on the beam. 'Trimming in' requires time and patience. Taping and papering the beams to protect them would have taken even longer. (7 beams running the length of the house).
After my marathon ceiling painting, my shoulders ached. My neck ached. My upper back ached. We had left overs for supper and I did nothing aside from a long hot shower (side note: the paint came out of my hair on the very first wash!)
Two days later, my right shoulder is still on strike.
Probably should have done things differently. Tim pointed out that there was no reason to get it all done in one day (after the fact). However, I stick to my original premise. That job needed to be done in one day, because it would have been pretty difficult forcing myself to return to it the next day. Glad it is done.