Paint manufacturers always say that you clean interior walls before painting. Recommended is trisodium phosphate (TSP), an inexpensive white powder that you mix with water to produce a mild cleaning solution.
As with so many products today, this recommendation ranges from sound remodeling advice and a statement created to limit company liabilities.
But do you really need to do this? Are there any instances when you can get by without cleaning walls before painting?
|Cleaning Needed||Cleaning Not Needed|
When You Can Avoid It
If you have a normal house, low-impact rooms, usual activities—you do not need to scrub with TSP when preparing to paint.
- Lack of excessive dust
- No Crayon, grease, or other substances on the walls that paint refuses to stick to
- No wood-burning fireplaces
- Little or no contact with skin
- No pets
- No cooking or bathing (thus, bathrooms and kitchens are excluded from this class)
- Walls, not horizontals like baseboard or door trim tops.
Areas That May Not Need Cleaning
- Living room that does not get a lot of activity and was painted only a few years ago.
- Master bedroom—i.e., for adults, not children.
- Dining room dedicated to dining only.
- Even a family room that is well-treated and has no wood burning fireplace.
- Powder room that is used only for toilet activities and hand-washing.
True, lightly washing with TSP is always preferable to not lightly washing with TSP. Simply put, clean is always better.
But if a full wash-down is preventing you from tackling the painting, then you should skip the wash.
Test to Determine If You Can Skip the Wash
At what level of uncleanliness can paint adhere properly?
Today's paints have greater tolerance levels for sticking to surfaces that are less than perfectly clean.
Take a dry white-colored cloth (cloth, not paper towel) and run it across the wall. Run it the entire length of the wall. If you can turn the cloth over and the color ranges from white to light-gray, you can skip the wash.
You should run it the length of the wall (at least 15 feet) as a control factor. For instance, even if you have an extremely dirty wall, running the cloth just a foot or two may not produce any color on the cloth, leading you to believe that the wall is clean enough.
Interior Painting Prep, Minus the TSP
If you skip TSP cleaning, then at least do the following:
- Remove the Big Stuff: Knock down the "dust bunnies" and cobwebs with a broom or vacuum.
- Trim and Baseboards: Use a lightly water-moistened cloth and run it across the tops of door and window trim and baseboards. These places will have significant amounts of dust. Cleaning them will help the painter's tape stick.
- Vacuum: With the bristle attachment on a home or shop vacuum, clean floor areas near the walls.
Priming your walls is also one way to encourage paint to adhere to the walls better without cleaning first.
Washing Alternative: Pole Sanding
Professional painters hate washing walls. There are many good reasons for this. For one, they're not in the business of washing—they're in the business of painting. For another, washing cuts into painting time, which cuts into their income.
In short, do not expect your professional painter to wash down all of your walls. He is not being lazy; he is being practical.
However, you may find your painter pole-sanding some flat surfaces with fine-grit sandpaper. This sloughs off sticky dirt and junk; deglosses surfaces; and knocks down some of the stipple.
If you're insistent on having him wash down all walls with TSP, expect to pay extra for this service Better yet, hire a cleaning person to do this before painting.
When You Need to Wash With TSP
You should definitely keep TSP on hand as an addition to your collection of essential painting supplies.
We would use TSP in the following instances:
- In kitchen areas that have accumulated grease.
- In bathroom areas that have soap scum. Or in bathrooms that get a lot of misted sprays, such as hairspray.
- In areas that receive a lot of skin contact (near door handles; door jambs; etc.)
- In rooms with unusual amounts of nonwater-soluble markings (for instance, Crayons in a kid's room).
- On walls, above heating registers.