With these stain-fighting methods, you can hide an ugly water stain on the ceiling while also putting a stop to the leak that caused it.
A water stain on the ceiling is typically the result of a leak in the roof, heating appliance, or plumbing that seeped through the ceiling and evaporated, leaving you with an unattractive area of dried, discoloured mineral deposits.
A word of caution: If you cover up a water stain without fixing the leak that caused it, you risk more discoloration on the ceiling, as well as more significant structural or electrical damage. That is why it is critical to identify and correct the source of the water stain as quickly as possible, even if the area is no longer wet.
Follow the steps below to identify and correct the source of the stains, then clean, prime, and paint over the water stains to restore your ceiling’s blemish-free surface.
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What to Do About Water Stains on the Ceiling
When dealing with a water stain, your first goal should be to locate the source of the leak (or, in rare cases, flood) that produced it—the roof, the upstairs radiator, and the upstairs bathroom are all ideal locations to look.
If the roof is to blame, look for and fix disintegrating shingles, deteriorated flashing (the weatherproofing material put on the roof), or damaged seals around roof vents, which can all lead to leaks. If you are unable to repair the roof leak, it may be necessary to replace it.
If it seems to be a leaking radiator, locate and repair the radiator body, valve, piping, or bleed point (where cold air escapes from the radiator).
Replace outdated caulking that may be allowing moisture to seep in and promoting leaks if coming from the upper bathroom. Repair overflowing toilets and unclog clogged sinks or shower drains that might cause water to flood the bathroom floor.
Make the required repairs, or hire a professional roofer, HVAC technician, or plumber if needed, and you should be able to avoid further leaks—and water stains—on the ceiling.
Now that you’ve addressed the underlying issue, you can go on to the stain itself, beginning with a thorough cleaning. Cleaning the damaged region of the ceiling with a moderate homemade bleach solvent (one cup bleach and three cups warm water) can fade the stain and remove any remaining mildew, grease, dirt, or dust that might prevent primer and paint from sticking to the ceiling.
Begin by laying a drop cloth on the floor beneath the stain and propping up a ladder to reach it. Climb the ladder while wearing safety gloves and goggles, and wash off the stain with a clean sponge drenched in the bleach solution. Wipe the moist area dry with a clean towel after rinsing the bleach solution off the ceiling with water from a spray bottle. Cover the ceiling trim with painter’s tape after the ceiling is totally dry to protect it from priming and paint.
It might be tempting at this point to simply slap a layer of paint right over the water damage and call it a day. However, since they are water-soluble, interior latex paints, which are often used on ceilings, are a poor choice for a base coat over a water stain. When a water stain comes into touch with latex paint, the stain dissolves into the wet paint layer as the paint dries, allowing the stain’s discoloured mineral components to show through the paint to the ceiling surface once more.
An oil-based, mold-resistant, stain-blocking primer in a hue that closely matches the existing ceiling is your best option for a base coat to conceal water spots on the ceiling. Because oil-based stain-blocking primers are water-insoluble, water stains will not bleed through. Unlike latex paint, these stain-blocking primers include a high concentration of binders (polymers that bind paint pigments) to ensure that the primer adheres to the surface over time.
The use of primer (and paint) is determined by the style of your ceiling. If you have a smooth ceiling, use a paint roller with an extension and a 38-inch nap roller cover to apply the primer over the water spots, then let the primer dry for two hours or as directed on the primer box. If your ceiling is textured, use a thicker nap roller cover (34-inch to 14-inch nap) or spray on the primer using a can of stain-blocking primer.
The primed section of the ceiling will often be a few shades brighter or darker than the remainder of the ceiling, drawing attention to the stained region. Painting over the prepped area will aid in colour matching it to the rest of the ceiling for a professional-quality cover-up.
Whether your ceiling is smooth or textured, you may apply a latex (water-based) or an alkyd (oil-based) ceiling paint over the oil-based primer—though latex choices dry quicker and generate less fumes from volatile organic compounds (VOCs) than their oil-based counterparts. Just be sure to choose ceiling-specific paint (like this one from The Home Depot), which is thicker than regular paint and has a non-reflective finish that helps cover tiny imperfections.
Choose a paint that matches the colour of your ceiling for a consistent look, then apply it with a roller over the primed area (a 38-inch nap cover for a smooth ceiling, or a 34-inch to 14-inch nap for a textured ceiling). Allow up to four hours for the initial layer of paint to dry, or as directed on the package, before applying a second coat for more equal coverage.
After the second coat dries, the ceiling should seem as if there were no water stains.