While you can put new drywall over old drywall, it’s not always the best option. In some cases, drywalling over drywall can make it harder to find wires and pipes behind your walls and conceal more serious problems with your walls. It can also make the room smaller. On the plus side, putting drywall over drywall can improve soundproofing and insulation. Plus, it’s often less expensive than tearing down and adding new drywall.

Yes, you can mount a TV on plaster walls—as long as you attach it to the studs. Alternatively, you can use toggle bolts, molly bolts, or another type of hardware that’s strong enough to support a TV. 

If you aren’t comfortable with this type of project, you can hire a pro. The cost of mounting a TV to a plaster wall ranges from $25 to $600 (or more), depending on the TV’s weight, size, and other factors.

In most cases, plaster repair will improve your home’s energy efficiency because a solid barrier of the insulative material helps keep conditioned air inside your home. Major plaster repair jobs like repairing large cracks or crumbling sections of plaster or applying a skim coat might make a noticeable difference in your heating and cooling bills. Not only can plaster repairs improve efficiency, but they can also reduce strain on your HVAC equipment, potentially saving you money on maintenance and repairs.

You may need to replace drywall because of smoke damage. If the drywall is covered in soot, you may be able to clean it, but it will require a lot of time and effort. You could spend hours cleaning the drywall only to find there is more damage and it needs to be replaced anyway. It’s usually easier and safer to remove the smoke-damaged drywall and replace it.