The age of your home can clue you in to whether you have plaster or drywall ceilings. Homes built after the ‘70s are more likely to have drywall ceilings and walls, while older homes have plaster. You can also do the pushpin test: A pushpin will go into drywall, whereas it’s much harder to push one into a plaster wall. If you’re still unsure, ask a drywall professional to let you know which type of ceilings and walls you have.

A post-drywall inspection could uncover many problems that weren’t present during the pre-drywall inspection, including insufficient insulation, missing weather stripping, improperly installed plumbing and lighting fixtures, flooring damage, drywall damage, plumbing leaks, aesthetic issues, and more. Structural problems, which are often expensive to fix and are common reasons to walk away after a home inspection, are easier to see before the drywall goes up, but a post-drywall inspection may highlight minor issues with house settling and foundation problems.

You should always hang drywall from the top down. Starting at the top makes it easier to create a straight, tight line between the ceiling and the wall. Any gaps that occur will be at the bottom, where they are easier to manage. You can either cut the bottom piece of drywall to fit the remaining space or cover the gap with baseboard trim. Additionally, starting at the top is physically easier, as you won't have to fit the top sheet into a tight space between the lower sheet and the ceiling, or try to balance the upper sheets on the lower ones while securing them.

A common cause of separation between a wall and the ceiling is truss lift—this can happen to the ceiling of rooms directly under the attic when the seasons change and wood building materials dry out, shrink, and shift. Roof trusses often dry out at different speeds, and if the bottom pieces dry out faster than the top pieces, they can shrink and pull the attached drywall away from ceilings and walls, causing cracks. Fortunately, truss lift is only a cosmetic problem, not a structural problem, and you can fix it by separating the ceiling drywall from the roof trusses, and patching the cracks.