IMHO, and based on my own experience, 3-4 days is nowhere long enough for a thorough job start to finish to do everything bottom side, even without problems. A good detergent pressure wash/rinse/blow dry to get any loose shite/grease off will eat into your time.
Weather will be a big enemy too. When I did mine it was blistering, so able to put in full succesive days.
Remember that when your successive and final coats of whatever go on, anything missed and painted over will be a waste of time and money.
Thats not to say that it can be absolutely100% guaranteed anyway, but I'm sure you get my drift. Good luck with it !!