A Handy Guide to DIY Decorating
Flaky Paint is a Decorator's Nightmare
The discovery of flaky paint is a nightmare for most DIY enthusiasts and home decorators. When paint flakes on plaster walls it is a difficult problem to put right. If you try to ignore the problem by leaving it on the walls it is likely to lead to expensive measures. Knowing some of the reasons paint becomes flaky may help resolve or prevent such problems in the future. There are several reasons for paint to flake on new plaster. Low quality cheap paints are more likely to flake than good quality paints. If the paint used is the wrong type it will not bond to the new plaster Avoid satin, silk and other special formulas or finishes such as kitchen or bathroom paints on new bare plaster, even if applying in kitchens, showers or bathrooms. Before applying the first coat of paint the plaster has to be completely dry. This is one of the biggest mistakes decorators make, too eager to get their new paint on the walls. Bizarre as it sounds, the finish of the plaster can sometimes be too good. The plasterer can leave a finish that has a very glossy surface. This looks and feels great but it can lead to a lack of adhesion for the new paint. New paint is also likely to peel or flake wherever there are problems with damp. Leaking pipes, defective appliances or structural problems can all be responsible for damp walls. Sometimes new paint will react adversely with old paint which can create some strange results. Usually these develop as a bubbled, marbled or cracked paint finish. Distemper, which shares its name with a canine viral disease, is a type of old paint that reacts badly to modern paints. Distemper has an unusual texture, it is generally off-white and quite soft. As it ages it discolors easily and may become powdery or dusty on the surface.
There are some sensible steps to take before applying emulsion paints to your walls. Check that the walls are bone dry and there are no problems with rising or penetrating damp. If the plaster is new or bare seal it with a mist coat of white matt emulsion watered down by 10%. When painting over existing emulsion paints or unknown paints, it is crazy what you find sometimes, try a test area to make sure there is no unwanted reaction. Another cause of paint reactions is mixing of paints, so avoid mixing different paints together. If you suspect distemper is on the walls try to scrape it all off. It is possible to seal distemper but my advice is to remove it. This is how to avoid causing flaky paint on plaster walls and could save some poor soul from a lot of wall scraping in the future.
Remove Flaky Paint from Walls
It is not uncommon to find some flaky areas in bathrooms or around windows where you may get some higher levels of condensation. When you get an entire room with flaking paint on the walls it is a different story. There is no option other than to remove every inch of it so that you can prepare walls for painting. If you leave any of it on the wall it may contaminate your paint roller or brushes and end up ruining the new paint in the tray, the finish on the walls and cause a general mess.
Methods of Removal
Brittle paint can be scraped off the walls with a strong bladed paint scraper. Keep the blade at an angle between 35 and 45 degrees. Work slowly and progressively ensuring that you don't damage the plaster. It is very hard work scraping large areas of wall and it produces a lot of dust. Gypsum plaster when scraped produces a very fine dust which is not good for the lungs. Wear an appropriate dust mask and eye protection. It is important to work up to the edges of the walls because these areas will show when decorated. The eye is automatically drawn to the edge of a wall not the centre.
Hair Dryer and Packing Tape Technique
Think back to how you discovered that the paint had a tendency to flake from the plaster. It was probably whilst stripping wallpaper . The paint came away easily with the wallpaper because it was loose. Packing tape is a good way to find out how flaky the paint actually is. Clean the wall with hot water and sugar soap (or any suitable detergent) to remove any old wallpaper paste (also known as size). When the wall is dry apply strips of adhesive tape and press them down securely. Peel the tape slowly to see if it picks up any of the flaky paint. If it does this can save a whole load of wall scraping, saving time and cutting the amount of dust created.
If the paint doesn't pick up with the tape you can try gently heating it with a hair dryer. This will make the paint elastic and if you are lucky it will peel in complete strips from the wall. As you pull the tape heat it with the hair dryer. When this technique works it leaves a perfect plaster surface behind. Take care when using a hair dryer as it gets extremely hot. This technique saves a lot time and makes a tidy job. The hair dryer creates a lot of hot air and therefore is essential to have good ventilation. If the heated paint creates fumes wear a respirator.
The Last Resort
If all the scraping has got you down and the packing tape didn't work you may begin to feel quite desperate. DIY forums on the internet will recommend you to do one or all of the following:-
1) Plaster over the problem
2) Use PVA Bonding
3) Wallpaper over it
None of which will leave an adequate finish for the paint. To re-plaster over the friable surface would probably result in poor unstable finish incorporating the flaky paint into it. PVA bonding is one of the main causes of flaking paint in the first place. To seal new bare plaster only use a mist coat of white matt emulsion paint watered down by 10%. Wallpaper over the poor surface might be the only viable option but there is always the risk that the wallpaper paste will not stick to the flaking paint either. Ultimately you have removed wallpaper because you wanted to paint the room. Another option that you may find on the internet are products claiming to be capable of removing the paint. Some of which look promising and they get mixed reviews. Paint and varnish strippers, some of which are Eco-friendly, all work in a similar way, they turn the paint back into liquid form, or more commonly a wrinkled goo. If you choose this route, it is a bit of a gamble, but if it works it will save hours of dry scraping. The downside is that paint strippers are expensive and they are very messy to work with.
No mater which technique you opt for there is always an area of wall where the paint did adhere to the plaster fully, usually where the original finish is rough. It won't scrape off, it is immune to paint strippers and has refused to adhere to the packing tape. The very last resort is to sand it down using an orbital-sander with dust extraction enabled. If this is out of the question try a sanding block and sandpaper (wear a dust mask). When you have removed the surface of the paint you can switch to wet and dry sandpaper, using it wet to cut the amount of dust and minimise damage to the plaster. Sand back until the area is completely smooth with no rough edges. When all the flaky paint is off the walls, prepare for painting as normal. Fill holes & cracks with filler before applying the mist coat. The mist coat is a coat of white matt emulsion watered down by 10%. Allow the mist coat to dry fully and spot all the filled areas until they do not show through the paint. Now apply the colour and finish of paint of your choice.
If you've read this article, I'm guessing that you have come across flaky paint on your plaster walls. I hope that something in this article may have helped and if not at least you can say that you have tried just about everything to get it off. At least you know that someone else has gone through the same experience. When you do finally decorate your room it will look great and all the scraping, swearing, dust masks and packing tape will soon be a distant memory.
Good luck and happy scraping.