We are working on replacing all of our interior doors. So far, my husband has hung 3 slab doors in the existing door frames. All three were tricky, and although they all worked at first, over time all have stopped latching properly. I’m guessing temperature changes have cause things to shift. Beyond that, you can tell by looking that the doors aren’t hanging straight in the frames. I should probably mention that we had the same problems with the old doors that were there before. My husband was careful and tried to do his research beforehand. He has also gone back and tried to adjust each door. Neither of us really knows the “right” way to do this, and I’m wondering if we need to consider buying pre-hung doors, or if the installation would be best left to a professional. We have five more to do, and I don't want to move forward until we come up with a better plan. I’m just curious to know what others’ experience has been.