Can you spray or roll on wall texture over an already painted wall?

The texture surface is way to rough in one room, plus it's painted with semi-gloss paint. I was curious if I could just re- texture the walls right over the paint? I want it smoother so I can apply wallpaper. Sanding would take forever!!Can you spray or roll on wall texture over an already painted wall?
If you want the wall smoother so you can apply wallpaper over it, I would first prime the wall with an oil primer (because it is painted in semi gloss) such as Zinsser's Coverstain or XIM 400 (provide good ventilation during and after painting).





Then you should skim coat the walls with drywall compound to smooth out the texture thus giving you a smoother wall to wallpaper over. Skim coating is the process of applying drywall compound to the entire wall. This is done by applying the compound with a broad knife of 12 '; or larger. You will probably need to skim it twice to get it smooth - allow the drywall compound to dry between coats. Sand the compound smooth. Vacuum off the dust and prime with a new construction drywall primer.





After the PVA primer has dried I would re-prime with a wall covering primer such as Zinsser's Shieldz.





You will have a smooth wall ready for wallpaper at this point.Can you spray or roll on wall texture over an already painted wall?
Yes, you can go over the paint with drywall mud but eventually you will have to do some sanding.
I'm afraid that if you don't want to sand then you are going to have to go with a rough texture wall. Try priming the wall and do a faux finish over it. I have done two of my rooms in this technique and there are great metallics out that Benjamin Moore Paint makes. Just pick up a base color and 2-3 metallics and some glaze. They have booklets, for free, that lead you through the process and you will love the rich soothing result.
you will need to use a primer on the wall to make plaster stick.





you might consider priming the wall and then applying a product that goes up like wallpaper made for flatting the wall.
Assuming the existing paint is latex you can prime over the wall with an acrylic primer/sealer like ';Gripper'; or ';Zinsser 123';, next, skim the wall with premixed drywall compound to fill the texture, sand and re-prime.


If you plan to wallpaper, applying an additional wallpaper primer like ';Shieldz'; is also a good idea.


Best Luck!
If you want walls smooth enough to apply wallpaper, you will have to 'float' out the walls with drywall mud, sand smooth, then start your wallpaper process.





Yes, you can put drywall mud over the paint.