Applying spackle is a simple DIY project that most people can complete in just a few hours. Even homeowners who have little DIY experience can complete this project in an afternoon. However, if you're uncomfortable with the project or don't have the time, you can always hire a pro to help.

Yes, you can install drywall over plaster, but there are important factors to consider. While it can create a smooth, flat surface, it is often not the best approach. Installing drywall over plaster will increase the wall's thickness, which can cause issues with existing window and door frames that may no longer fit. You might also need to adjust power outlets to keep them accessible. A better, though more expensive, option is to remove the old plaster and lath entirely before installing new drywall. Drywalling directly over plaster seals in the old material, and if any problems arise later, you will need to remove both layers down to the structural beams for repairs. Given the potential complications, this job is best handled by professionals.

The easiest way to cut holes in drywall for electrical boxes is to use a spiral saw with a drywall router bit. Hang the drywall without cutting out a hole for the box, but make sure you measure and mark where the box is located on the wall. Once you screw in the drywall sheet, drill a small hole into the box void, insert the spiral saw bit, and move it around the edge of the box using the inside wall as a guide. You can also use an oscillating multi-tool with an electrical box cutout for fast, professional results.

Whether to repair or replace water-damaged plaster depends on the scale of the damage. For small, limited areas, you can often perform a repair yourself. If you choose to paint over small patches, ensure the surface is completely dry and apply a coat of antifungal primer first to prevent mold growth. However, simply painting or plastering over the damage is only a temporary solution that doesn't address the core problem. For more extensive or long-term damage, the plaster may be compromised, and there is a risk of mold. In these cases, it is recommended to remove the damaged section of plasterboard and replace it. You may consider hiring a professional for the repair, and it's worth noting that water damage is often covered by home insurance.