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.

If your premixed drywall mud is dried out or has begun to set in the bucket, you may be able to revive it by adding warm water and stirring. However, the first and most important step is to scrape off any hard, dried bits of drywall that may have accumulated toward the top of the container and throw them away because they will not easily reconstitute back into the drywall mud mix.

In framing, studs are placed at 16-inch intervals to coincide with the typical spacing of wall materials such as drywall or plywood. This spacing is called "on-center" and is necessary for maintaining structural stability and efficient use of materials. The 16-inch spacing also helps to distribute the weight evenly across the building's structure. For those looking to cut material costs and improve energy efficiency, 24-inch stud spacing can be employed through a method called "advanced framing". This requires careful planning and adherence to local building codes to ensure structural integrity.

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.