Interior Painting 4 - Preparing the Wall
Preparing a Room for Paint
Prepping a room for painting isn’t as exciting as laying down new color, and no one will ever compliment you on how well you set up a drop cloth, but proper preparation is the key to a good looking, long lasting paint job. Without proper prep, a paint job may look pretty good at first. But sooner or later the poor quality will show up.
There are several basic things to do to get your room ready for your roller.
Make Repairs - First, make any repairs to the room that need to be made. Any dings or cracks in the walls need to be corrected, or they will show through in the end.
Protect the Floor and Furniture - Use a drop cloth to cover the floor. Move any objects you are not removing from the room away from the walls and gather them together in several out of the way spots around the room. As professional painter Ed Kimble, author of interiorhousepaintingblog.com, says, “Think of a chain of islands spread around the room rather than a huge continent in the center.” Make sure there’s space to maneuver and set up a ladder between the objects. Once you have your “islands” of objects, cover them all with drop cloths.
Remove Switch Plates - Turn the electricity off and remove any switch plates and outlet plates. Use blue painter’s tape to cover the switches and outlets.
Mask the Trim - If the trim pieces aren’t going to be painted, mask them off with painter’s tape. Mask around the edge of wall to wall carpeting with at least two inches of tape.
Clean the Room - Vacuum and/or mop the floors and all ledges to remove all dust and debris.
Set Up Your Tools - Assemble ladders, buckets, materials and so on in the room before beginning. Create a space outside the room for paint cans and other materials and supplies, so they don’t get in the way while you work.
Sand the Walls - Lightly sand the walls and ceiling you are going to cover. You are not trying to remove the old paint, but creating a slightly rough surface for the new paint to adhere to.
Prime if Necessary - A primer coat of paint is recommended if you are painting porous materials like bare wood or concrete, or some metal surfaces. Otherwise, it’s not usually necessary. Ask your paint supplier about your particular situation.
Correcting Peeling, Flaking or Bubbling Paint
Most of these problems are caused by lack of proper preparation when the previous coat was applied. Peeling happens when the last coat of paint didn’t adhere to the surface. Perhaps oil-based paint was applied over new plaster, trapping moisture between the surface and the paint, or enamel surfaces were not roughed up first. Maybe the coat of paint was not compatible with the one it was applied over, as in using oil over latex. Also, dampness and leaks in the wall cause many of these problems. Make sure to repair any leaks before you paint.
If these conditions exist, use a quality paint scraper on the problem areas until they are relatively flush with the wall. Follow up with a fine-grit sandpaper (100-grit silicon carbide) to smooth out the areas. Finally, wipe with a tack cloth to remove all dust.
If a water stain shows evidence of black mold, wipe the area with a mixture of one part water to one part bleach and allow it to dry. Use a stain blocking primer on these areas.
If all this leaves ridges or dips, they will be visible once the wall is painted. If the dip or indentation is too great, fill it with drywall compound and sand it down. Be sure to prime any newly applied drywall compound before painting or papering.
Prepping the Woodwork and Trim
You will be painting your woodwork and trim last, but you need to prep it before beginning to paint, or else the debris from prepping will settle on the new paint. Usually woodwork and trim are painted with an enamel or glossy paint. You have to rough up the old paint so that the new paint will adhere properly. Lightly sand with steel wool or fine-grit sandpaper.
Sometimes, you need to scrape off old deteriorating paint. If it's in bad condition you may even need to use a water-soluble gel remover. Fill all dents and gouges with wood putty or patching compound. Avoid fast-drying compound; it is hard to sand. If the gouge is over 1/8-inch, use two layers. Always sand where the old paint is breaking away from the underlying surface to create a smooth transition.
Now that the prep is done, you get to move on to the actual painting.