Clear furniture or other movable items out of the area. Tape large sheets of bubble wrap to the inside edge of the pool to keep the pool clean and free of debris. Also cover landscape plants or areas of the house where the old patio abuts the house structure or plants.
You can use a shot blaster or a scarifier to clean and sand old or damaged concrete pool decks. A strong power washer may be able to handle the job if the deck is lightly damaged. Both are typically available for rental.
This can be a really dusty, dirty job so be sure to wear masks and clothe yourself accordingly. Work your way around the entire patio area with the machines.
If you have very large cracks to fill, you might contract with a professional who can use a concrete wet saw to cut around any large cracks that need filling.
Fill all cracks with wet concrete patch, using a concrete float to smooth the surface and level it with the surrounding concrete (Image 1). If a large crack goes to the edge of the concrete, you may need to build a form to hold the gravel and concrete before filling the crack (Image 2).
Once all of the concrete patches are dry, pressure-wash the entire deck surface. This will wash away any dust or particles left behind by the shot-blaster and prepare the deck for the new surface. Remember to wear safety glasses when using the pressure washer.
Unless you feel confident that you can manage the next step by yourself, contract with a professional to use a power sprayer to apply concrete micro-topping material to the entire deck. Micro-topping is a cement-based (often polymer-enhanced) product that provides a uniform texture and color to the surface. Its uniform application can be tricky to achieve without having areas with too much or too little micro-topping
Let the new surface dry overnight; do not walk on the surface for 12 hours while it cures. Check the manufacturer's instructions for specific drying and curing times.
With a professional choose the colors and textures you desire for the finish coat.
If you have a pool, the coping will receive a different color than the rest of the pool deck. With a professional concrete finisher, mask off the deck and spray the coping with an acid concrete stain in the desired color. Check the color by spraying it on a small, inconspicuous area of concrete before spraying the entire coping. Let the stain dry according to the manufacturer's instructions, usually overnight.
Once the stain is dry on the coping, work with the professional to mask off the coping. Then spray acidic concrete stain (of a different color) on the pool deck. Apply the color evenly and spray the entire deck in one session to keep the color uniform. Let the area dry overnight before removing the masking.