Now that the room is masked off we are ready to begin the removal of the acoustic-popcorn material from your ceiling.
Never wet down a ceiling and leave it for extended periods of time. The water will soak thru the acoustic and damage the drywall and cause the drywall joints to pop loose and increase the amount of repair work needed before you can apply wall-ceiling texture. When you are ready to scrap off the ceiling wet it down as outlined in the next step but do not wet the ceiling unless you are ready to start removing it right away.
Using the garden house with the spray nozzle attachment lightly spray the ceiling with water. How much water and how long you need to wait before removing depends upon the thickness of the acoustic on the ceiling. This will vary based upon the technique of the person who sprayed the ceiling and if the ceiling had ever been re-sprayed.
Sometimes you will encounter a ceiling that has been sprayed 3 or 4 times and it will be quite thick. Spray several light coats of water until the acoustic turns a medium gray.
If the ceiling has ever been painted the water will not want to penetrate as easily as an unpainted ceiling and will be repelled by the paint. These ceiling will require several light coats of water. Spray with water then test by attempting to remove a section. If the ceiling does not release easily spray again with water and try to remove another test area.
Before starting ensure that your drywall knife is not damaged. Hold the knife if front of you and look across the blade. If there are any waves or bent corners replace the knife.
From a technical view point this is actually an easy process. Take your drywall knife and hold at a 15 to 20 degree angle. Push under the acoustic being careful not to dig into the drywall tearing the paper coating. This is one of the most common mistakes made by novices attempting a DIY removal.
Sometimes when the walls are painted the paint will overlap onto the acoustic along the edges of the wall. Using your knife hold it along the wall and using light pressure run it along the masking tape to score a line allowing the acoustic to fall free.
When you encounter a drywall joint you should scrap down the length of the joint and not across the joint. Try to minimize removal of the joint compound that is covering the joint and you will decrease the amount of work needed before you can apply wall texture.
After all the acoustic is off the ceiling allow it to dry for a few minutes then sweep down with a broom to remove any stray bits of material.
Congratulations! You have now removed that ugly Acoustic/Popcorn ceiling and are ready to begin the repair process and recoat the drywall joints and nail heads.