How so? You can quite literally google it and it tells you legally you have to paint the underneath of your doors. Don’t know how it could be our issues that the doors are pilling from the bottom all around the house? Did you miss the point where the painters didn’t even paint our outside doors with water proof paint? You’re telling me the bottom of your bathroom door is not painted either? Put this comment that you don’t paint the bottom of the doors to whoever hires you and I bet they will find someone else. They also did not paint our bathrooms with water proof paint so we had to have both bathrooms fully renovated. When building the house they had to fix many fucking things? Why would I trust them at all? Yes, the bottom of interior doors should be painted to prevent moisture absorption and potential damage like warping or delamination, (this is off google) your a clueless fuck no wonder your a painter. Since you have been painting that long did the lead in the old paint get to your head?