• Remove all furniture (if possible),
• Cover floors with painters drop cloths and furniture with plastic,
• Remove damaged  drywall, plaster,
• Support  the rest of drywall or plaster with board adhesive, screws, studs,
• Seal damaged areas with oil-based primer,
• Install insulation (if required),
• Install drywall support: for small damages – stiff mesh, for bigger damages – wooden studs.
• Install drywall,
• In some cases we install metal mesh and apply plaster compound,
• Tape, patch, sand and prime with PVA primer,
• Paint the ceiling with flat or semi-gloss  (Bathroom) paint.
• Clean the job site.
• Get paid

Usually the whole process takes one day.

Drywall is a common material used in building construction and is known for its versatility and durability. However, it can be easily damaged by water, which can result in unsightly stains, bulges, and even mold growth. Here's a general guide to the drywall water damage repair process:

1. Identify and Address the Source of the Water Damage: The first step in repairing drywall water damage is to identify and address the source of the water damage. It could be a leaking pipe, roof, or window, or a flood caused by a natural disaster. Once the source of the water damage is identified and addressed, it's essential to ensure that the area is dry before proceeding with the repair process.
2. Cut Out the Damaged Area: The next step is to cut out the damaged area of the drywall. This is typically done using a drywall saw or a utility knife. The cut should be made about one inch beyond the water damage area to ensure that all of the affected drywall is removed.
3. Replace the Damaged Drywall: After the damaged drywall has been removed, the next step is to replace it. A new piece of drywall should be cut to fit the hole, ensuring that it is the same thickness as the existing drywall. The new piece of drywall can be attached to the existing drywall using drywall screws.
4. Tape the Seams: After the new drywall is in place, the seams between the new and old drywall should be taped using drywall joint tape. The tape should be applied in a thin layer over the seams, and excess mud should be smoothed out with a trowel.
5. Apply Joint Compound: Once the tape is in place, joint compound should be applied over the tape to cover the seams. The compound should be applied in thin layers, and each layer should be allowed to dry completely before the next one is applied. The number of layers required depends on the depth of the seams.
6. Sand and Paint: After the final layer of joint compound has dried, the area should be sanded with fine-grit sandpaper to ensure that it is smooth and even. Once the sanding is complete, the area can be painted to match the surrounding drywall.

In conclusion, repairing drywall water damage can be a relatively straightforward process, but it's important to address the source of the water damage and ensure that the area is dry before starting the repair. With the right tools and a little bit of patience, you can restore your drywall to its former glory.