Scrape off the old paint I'm pretty sure they had wall painting in mind when they said it. Before painting on old paint on wood, all loose, cracked, chipped or peeling paint must be abrasively removed. Once this is done, the wood will be ready for a good adhesive primer. Whether you switch from a painted finish to a varnished finish or from an oil-based finish to latex or any combination of these, you'll get better results if you remove old finishes and start over.
However, if the paint in your house is so thick that you have lost the definition of shingles, trim profiles and decorative carvings or if you want to reveal the grain of the wood that hides the paint, then at least some degree of paint stripping will need to be removed. Painting on walls painted many years ago may not seem uniform and pleasant, leading to a waste of time, money, efforts and resources. A new coat of paint from a professional paint contractor gives the property an improved appearance and the walls a new lifespan at an affordable cost. You can repaint walls over old paint if there are small stains and stains that you can easily clean, which also works well when the new color is similar to the old paint.
Any new paint will rest on that base and will only last as long as that old paint (the base) lasts. Have professionals remove old paint and repair walls with proper treatment before applying a new coat of paint. However, removing old paint can be important if you want to get the best results from your painting job. A common question that bothers most homeowners who are considering repainting is whether they should remove old paint from walls before repainting them or paint directly on it.
Loose, cracked, and peeling paint needs to be removed abrasively, before painting over old paint on wood, as shown below. Turn down the heat and add some moisture and you'll get an effective, old-fashioned way to remove paint that helps remove excess dust (which is what makes removing lead paint dangerous). New paint may not adhere properly to walls and there is a greater chance that newly painted walls will develop defects. Use the best ways to scrape old paint off the wood coating, making this preparation step as easy as possible.
If you're the owner of a home built before 1978, there's a good chance you have lead paint lurking somewhere in your house.