Walls – What type of wall texture is this

• Preparation: definitely use a drop cloth. Because it's a wet job, I'd also recommend a putting down a layer of painter's plastic on top of the drop cloth. This will catch most of the splatter and makes clean-up a lot easier -- simply roll up the plastic. I believe the texture compound has some adhesive properties, so as long as the walls are clean, it'll stick just fine.

• Fixing mistakes: you'll have several minutes to decide if you like how the job looks. If it doesn't, just scrape off the texture and start over.

• Tools: a knockdown knife is much bigger than most taping knives, so you have to do fewer passes with it for a given area, so fewer places where you could have lines. My texture guy actually uses a hawk instead of a knife (he puts globs of texture on the hawk, then presses it onto the wall), so the tool doesn't really matter.

• Tips: don't use too much texture compound; each droplet will get spread out quite a bit when you knock it down. Don't press too hard with the tool: you're spreading it out, not scraping it off. After it dries, you'll likely have little pointy bits sticking out where the tool pulls away from the wall; go back over the surface with your taping knife to knock them off (otherwise they'll break off when you roll primer or paint over them and you'll have little bits of texture in your paint!)

That looks like skip trowel. Regardless, your solution depends on if it's plaster or drywall mud.

If it's plaster, you can skim coat it or have it removed and reapplied. Both require a bit of skill and it's best done by a professional. This will not come cheap.

If it's just mud, a skim coat is fairly easy to do but takes time and patience. You can thin down some ready mix mud, apply it with a 3/4 nap roller, then scrape off the excess with a 12" drywall knife. This will probably take a few coats, but it can be accomplished by a diyer. After you have the wall to mostly smooth plane, prime with PVA and you can apply your orange peel texture. Then just prime and paint.

Another solution is to put on 1/4" drywall directly over it. But this is a big job with taping seams, altering trim around doors and windows, extending electrical boxes, and applying texture.

Just to cover all options, it's "possible" to sand smooth. Even renting a power sander hooked up to a shop vac, this will produce a lot of dust. Plaster and certain drywall mud types are really hard to sand. I wouldn't do it.

Also, I would rent a texture sprayer. The cans of texture are really only for touch up and the fumes are pretty bad. Mask off with builders paper or poly sheets anything you don't want texture on. It's all in the prep work.