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What To Do Before Painting Over Water Stains
This whole process starts with identifying where the water is coming from. If you notice leaks during storms, check your roof for holes. If water is pooling in your basement, check for a split pipe.
If you don’t properly fix and stop the leak, all your painting and repairs will be for nothing. You’ll have to start over again every time a new leak springs.
Repairing The Damage
If you’ve checked everywhere and can’t find the water source, then it’s time to call in a contractor for an inspection. Faulty caulking or a leaky HVAC can be tough to spot on your own. Schedule an inspection with a contactor at All Dry USA and locate any pesky leaks today.
Not until the damage or leak has been stopped will you be ready to move on to the next step.
Before you break out the paint, you’ll have to dry out the damp areas completely. Never apply primer or paint to wet walls.
First, remove all surface water you can see with a rag that you don’t mind throwing out. If you have water on the floor, you can use a water vacuum or a shop vac for faster, efficient removal. But beware, as these methods are not guaranteed to reach every nook and cranny that water can hide in.
It can take professional equipment to dry out grout or cracks in a wall fully. Water damage can even end up behind your drywall which you will not reach on your own.
But drying is more than removing visible surface water. Drywall is porous, and water can soak all the way through. Open the windows for a cross breeze, or bring in a dehumidifier if you live in a humid climate. Expect this process to take up to 24 hours for 100% effectiveness.
If you’ve had a long-term leak, there is a chance mold and mildew have already begun to grow. In fact, mold starts to grow in damp areas after only 24 hours. Mold is fairly obvious to spot. It usually shows up as black or brown splotches appearing slimy or fuzzy. If a musty wet scent is coming off the water-damaged areas, that’s also a clear sign of mold.
These toxic spores need to be removed before you proceed. They can cause serious health risks to you and your family if left untreated.
At-home mold removal sprays can be toxic, so it’s best to consult mold removal professionals for this operation. If the mold has grown all the way through your wall, the entire section may have to be replaced.
You can combine bleach and water in a 1:3 ratio in mild cases to make a sanitizing solution. Use a sponge and work this mixture around the discolored areas until you start to see the color disappear. If you attempt to sanitize the mold on your own, make sure to fully dry the affected area again before moving on to painting.
1. Treat Mold or Mildew
Feel the wall for dampness and visually check for signs of mold or mildew. If either is present, wipe the surface well with a diluted mixture of water and chlorine bleach to remove it.
4. Sand Damaged Drywall
Sand the area with medium-grit sandpaper attached to a sanding block to ensure a level surface. Follow with finer grades of sandpaper until smooth.
How Do You Get Rid of Water Stains?
If a water stain has caused any damage, e.g. cracks or flaking plaster, make sure that you repair the area first. This will help get a great finish and improve paint adhesion.
To cover the stain, you will need a specialist stain blocker (such as the Zinsser Cover Stain (opens in new tab)) or an oil-based paint. This creates a waterproof barrier that the water stain won’t be able to penetrate.
If you already have an oil-based undercoat or gloss at home, you can save yourself money by using these. Use the undercoat by itself, or mix with the gloss to create an effective homemade stain blocker.
Make sure that the water stain is dry, then simply paint over it using a brush or roller and leave to dry. Feather the edges so that the paint blends with the surrounding area. One coat should be enough.
Once dry, you can then apply your emulsion for the final coat to hide the stain. However, you may find that the new paint and old paint don’t quite match. This is a good time to give the whole ceiling or wall a few new coats, testing different types of paint and finishes to get the best results for your living space.
How Stop Stains Coming Through Emulsion Paint
Here’s out step-by-step guide to stopping water and damp marks showing on your ceiling:
- Find and fix the cause of the water mark: This can be tricky, but there’s absolutely no point trying to deal with the water stained paint until you have done this. Make sure that the ceiling (or other surface) is completely dry
- Prepare the ceiling for painting: Often the surface will have become damaged and so you will need to patch any cracks and gaps with filler. If the plaster has blown, you might need to re-plaster – See here for more information
- Apply the barrier to stop the water mark: Whether you use your own or a product specifically purchased for the job you will need to use this to stop the water mark coming through the emulsion
- Paint your ceiling (or stained surface): You can now paint over the area that was stained and be confident that the water mark will not return
You might end up having to paint the whole ceiling as the old paint might have become discoloured over time and to get an even colour across the whole surface, the only thing to do is to paint the whole thing.
All project content written and produced by Mike Edwards, founder of DIY Doctor and industry expert in building technology.