If your building has been covered in graffiti, you may want to make sure that you get that covered up as soon as possible. That's because it isn't going to give your customers a good first impression of you or your business. There are things that you can do that will help you make sure that your building looks as good as possible. The best thing you can do is to call a commercial painting service and have them deal with it for you. There are several steps that they will have to do in order to handle the graffiti, but once they do it all, the wall will look good again.
One thing that the painter will need to do to start is to sandblast the wall. That will help get rid of the graffiti, but it will also help to make sure that all the loose paint chips and dirt are also off the wall. That will give the new paint a nice clean place to stick to and will make the finished product look very nice and very smooth.
Once they have everything nice and clean, the painters will be able to put a base coat on the wall. The base coat will help to hide any remnants of the graffiti that were still on the wall after being sandblasted as well as covering up any crazy kind of color that may have already been on the wall. It will give the new paint color the best chance to actually look like the color you chose.
Once the base coat has dried, it will be time for the color to go on the walls. It may take more that one coat of paint to get the color you are looking for, and they may have to wait for a day in between each coat so that the paint can dry.
There are also coatings that the painter can put on the wall over the paint. These coatings are designed to be "slippery", meaning they will make the spray paint or pens that the graffiti artist may use to try to put graffiti on your wall ineffectual. That means that they won't be able to do anything. The painters may have to come out and renew the coating for you periodically, but that's better than having to deal with graffiti removal.
If your business gets hit by graffiti on a regular basis, you are going to want to do what you can to make sure that you don't have any problems with it.