Ceiling water stains are unsightly and getting rid of them is fairly difficult. The best course of action is to ensure that you don’t get ceiling water stains in the first place. This usually requires good household maintenance. More importantly, it can save you a lot of frustrating work later on. If you have ceiling water stains, the problem might be located away from your ceiling and these repairs could end up costing significant sums of money.
Step 1 - External Leaks
The biggest source of leaks in a house is the roof. You need to check the roof regularly to replace lost shingles and to glue down loose shingles with roofing tar. You will also need to check the flashing. The flashing will be around the chimney and around any protruding pipework as well as skylights.
Flashing will eventually become loose where it has been battered by the weather. If this is the case, replace it and caulk all the seams as well as using roofing tar where it meets the shingles. This will prevent any water entering and causing a problem that could eventually cause a ceiling water stain.
If you have a gable roof with a low slope, you should climb up every fall and make sure the roof is clear since any debris could cause a blockage of snow and ice that could cause a leak. You also need to check your gutters and downspouts since a blockage can cause water to back up and leak into the attic. Clean gutters every fall once the leaves have fallen and make sure there are no blockages in the downspouts.
Step 2 - Internal Leaks
Check your attic. If you have warm air laden with moisture escaping up into the attic, it can cause mildew. Moisture can also condense or freeze in the winter. This can lead to a ceiling stain if it drips down into the ceiling.
Check that the kitchen and bathroom fans are ducted outside. If they’re not, you'll need to install an outside vent for them. The warm air could also be coming from small openings around the light fixtures below or even at the entrance to the attic. Use insulation or weather stripping to seal these areas. You should also make sure that your vents in the attic are unobstructed so fresh air can circulate.
Where you have an upstairs bathroom, you need to regularly check the caulking on the tub or the shower. If it’s not tight, water can leak through and this will cause a ceiling water stain over time. Remove the old caulk and recaulk completely.
If the pipe under your upstairs bathroom sink is wet, you need to do something about it before it causes a ceiling water stain. If the damp has spread all over the pipe, this is easily fixed with some pipe insulation.
Step 3 - Eliminating Water Stains
You can’t just paint over ceiling water stains. To hide them and prevent them showing again, you need to use a special stain-killer primer before you paint. You can also use shellac. Once these rectification measures have been used, ceiling can be decorated again using traditional methods although a coat of primer should be used before applying any topcoat to form a further protective barrier between the ceiling stains and the final choice of color.