"I have a painting problem: All the walls and ceilings in my apartment have been painted using a sponge technique. The paint itself is a latex flat base to which powdered pigments were added along with a small amount of an abrasive material to give the walls an "adobe" look.
I now wish to repaint and return my home to a "normal" sleek appearance.
Would you be able to suggest the steps I need to follow to achieve this?
The most difficult problem to cover would be:
1) uniformly rough surface due to the abrasive material and uneven application of the paint using sponge technique
2) dark colors ranging from orange to brown.
How should I proceed?"
There are several approaches to removing or covering textures on walls and ceilings.
Because of the labour involved in all the other techniques, the tactic generally taken by contractors is to simply scrape off any exceptionally high picks and then cover the entire wall with 3/8" drywall and start all over with tape in the joints, primer etc. This does require removing the baseboards and window and door trims and sometimes adding wooden filler strips for the windows and doors to accommodate the extra thickness.
If you do not wish to just cover it with drywall, it can be smoothed over with drywall compound or finishing plaster -- but to get a large surface actually flat takes the experience of a professional -- not a first time DIY project.
If you choose to actually scrap the surface flat, being careful to not gouge into the drywall too much, you could easily put a skim coat of drywall joint compound over the entire wall to make up for the little holes caused by pieces of the grit that popped out or small valleys that are left. This is easier to do than trying to float a coat over a rough surface because you are not raising the entire surface but rather filling in dents and picks. You will probably need to work hard on a first coat, pick up little misses or gouges with touch up work on a second and perhaps third coat. Then prime and paint the wall.
One thing that would be worth testing, but it only works on certain paints and textures: use a heat gun and a wide spatula to scrape off the texture. Try this in a discrete corner and see if it is not easier than cutting with a sharp pull scraper. When the paint is acrylic it will often peel off fairly easy once heated up. Expect a few gauges and some drywall compound patching but the surface can come out quite smooth.
Apply a full primer coat. Don't forget that the cheap primers do not hide colour differences well. More information on Primers.
I hope this helps