Condensation Stains on Walls: Solution for Sweating Bathroom


If your bathroom walls are sweating, getting rid of condensation stains can be difficult. Luckily, there are a few simple tricks to get rid of them for good. 

In most cases, fixing condensation stains on walls means isolating the problem, installing ventilation, and then fixing the water damage. That can require considerable effort depending on the age of your bathroom and where it’s located in your home. 

How to Remove Condensation on Bathroom Walls 

If you have condensation or stains on your bathroom walls, it can be difficult to get rid of. Unfortunately, condensation normally relates to air flow and temperature differences. There may not be an easy fix. 

Condensation Marks on Bathroom Ceiling 

In most cases, the easiest way to remove condensation marks on the ceiling of your bathroom is using a homemade bleach solution. However, it is important to note that this resolves the symptoms and not the cause. Therefore, without making other changes in your bathroom, the condensation stains will come back. 

Fixing the Stains

To bleach your ceiling, you want a diluted bleach solution. In most cases, 1 part bleach with 3 parts warm water is more than strong enough. You should prep the bathroom before you make this. Prepping for bleach means removing any fabric, removing objects that might be damaged, and removing shower curtains. You can then cover any tile or wood floors that might bleach to a different color. Then, put on gloves, goggles, and clothing you don’t mind ruining. Use a cleaning extender, like one made for washing windows or use a stepstool to reach your ceiling. Then clean any dust or cobwebs off your ceiling. If there’s actual mold, don’t touch it, because getting it into the air can be harmful and will cause mold spores to spread. 

Then, use a spray bottle to apply the bleach solution evenly across your ceiling. In most cases, bleach can change the color of old plaster – so if you have a plasterboard (gypsum, sheetrock) ceiling, be sure to evenly spray the whole thing. 

Importantly, if the plaster is chipped or cracking, you’ll have to take it out and replace it to fix it. 

Condensation on Walls in Summer

Condensation builds up on bathroom and interior walls in the summer because the interior of your home is markedly cooler than the outside. This causes condensation to build, which with poor ventilation, does not dry. Eventually, you get condensation marks on the walls. 

Cleaning Water Stains off Walls 

Unfortunately, walls can be more difficult to clean than ceilings, because they’re normally painted with darker colors. Where ceilings are usually white and safe to bleach, you might have painted your walls. If that’s not the case and you have white or tile, use bleach. If it is the case, try using a gentler solution first. For example, one gallon of water to one tablespoon of ammonia, a quarter cup of vinegar, and a quarter cup of borax. This solution is gentle but should help you lift and remove the stains. Apply the solution to the full stained area. 

Water Streaks on Painted Walls

Water or drip streaks on your painted walls can be treated in the same way as above. Of course, you always want to clean the surface first to ensure there’s no dust or dirt or other residue. Then apply the borax and ammonia solution. You also want to make sure the windows or doors are open, so you get plenty of air while using toxic chemicals. 

Moisture in Drywall 

Moisture can greatly damage drywall, even if it’s caused by condensation. In most cases, you want to avoid using bare drywall in bathrooms for this reason. However, fixing it normally involves using paint. In this case, we’ll assume you’ve fixed the base problem of the condensation first. Otherwise, your drywall will continue to damage and will continue to have stains. 

Sand the Drywall

The first step is to take a fine sandpaper (think #600) to the stain. The goal is to smooth out the bumps and ridges left in the paper from the water marks. The smoother the drywall, the better. 

Prime the Stain 

Then, take a stain preventing primer and cover the stain. This prevents the stain from bleeding through the drywall and into the paint. Why might that happen? Stains cause discoloration. Over time, that discoloration can work its way out of the paper and into another substance, like your paint. Using a sealing primer first prevents this. 

Paint and Sand the Primer 

Once the primer is dry, sand the edges to make them smooth against the rest of the drywall. Then, add a topcoat to hide the primer and paint your full wall. 

Condensation on Ceilings in Winter 

Condensation on your ceilings in the winter normally means it’s considerably warmer inside than outside. That’s especially common when you take hot showers with no ventilation and steam adds to the problem. Without adequate ventilation or insulation, you’ll always have this problem. 

However, once you’ve resolved the insulation and ventilation, fixing the issue is the same as fixing condensation on your ceiling in the summer. You’ll also note it’s simply the opposite cause. So, while condensation in the summer is very common in hot and arid climates, condensation in the winter is more common in cold climates. In some rare places, you might get both, but it is unlikely. 

To resolve the stains, simply bleach your ceiling with 1 part bleach and 3 parts warm water. You can spray it on with a spray bottle or use an old towel or rag to do so. 

Why Do My Bathroom Walls Have Water Streaks? 

Drip marks or streaks occur on bathroom walls for three reasons. All three have to do with water buildup. The first is that if you have inadequate ventilation, water builds up when you shower. Steam rises from your shower and goes into the bathroom, and then collects on the ceiling and on walls. When it builds up enough, the water drips down. Eventually, this leaves streak marks – which can be permanent without paint. 

The second reason is that if your bathroom is poorly insulated, it can be significantly warmer or colder inside than the outside. The lack of insulation can cause condensation to build up on the walls, normally around contact points with the outside. For example, an exterior wall or the ceiling. Then, water builds up and drips down. Like with the steam from the shower, this can and does leave water streaks. 

The third and final reason is about ventilation when you paint the bathroom. If there’s not enough airflow at the time of painting, your paint may dry unevenly. This can create a permanent streaky look. The only way out of this is to repaint the bathroom – but making sure you keep fans running and doors open until the paint is dry. 

All three issues are related to the same problems. Inadequate ventilation or inadequate insulation. Those two issues are the primary reasons for nearly all bathroom condensation issues. 

How to Stop Condensation on Walls and Ceilings 

There are several very easy ways to stop condensation on your walls and ceilings but none of them are expressly fast or cheap. However, you can take significant steps on your own to DIY your way out of condensation walls and ceilings. On the other hand, you may prefer to hire a contractor who can do the work for you at a professional level to be sure. 

Use Fans While Showering 

If you’re looking for a quick fix, most people can fairly easily move a fan into the bathroom while showering. You’ll want to turn it on when running the water and then leave it on for a bit after getting out. This keeps air circulating, which will help the condensation to dry out. In most cases, you’ll want to put the fan on a timer, so you can just leave it alone. 

While this fix will solve light issues, it’s not enough to be a permanent problem-solver. However, it is a great intermediate step between installing a permanent solution. 

Open Doors and Windows While Showering 

Like with using a fan, opening doors and windows should not be a permanent fix. Why? Doors and windows allow ventilation in and allow air to circulate. However, it is inconvenient, and you might not get enough airflow every day. Opening the doors and windows is also going to be much too cold in the winter. So, consider this a temporary, summer fix while you plan the next two steps. 

Install Insulation 

Installing new insulation can prevent condensation and wet walls when you haven’t used the shower. If you frequently go into the shower and things are wet, it’s likely an insulation problem. Hiring a contractor or buying insulation yourself can solve this problem. Here, you want to insulate any outside walls and the ceiling. If your bathroom is normally warmer than the rest of your home, you should insulate the inside walls as well. 

Installing new insulation can be costly, but it does a lot to prevent condensation and water buildup. That’s especially true if you frequently see water buildup on outside walls. And, of course, it will reduce your heating and cooling bill over time. Because most states actually offer subsidies for installing insulation, you might even get some money back if you hire a contractor to do the work for you. 

Install Ventilation 

Installing ventilation normally means installing a powered vent and hood in your shower, normally directly over the shower. This should trigger and turn on when you turn on the light or the shower/bath. Ventilation works as a vacuum to remove moisture and steam from the shower, as it rises up. This prevents it from collecting on the walls and ceiling – thereby preventing your condensation issues. 

Good ventilation will also help to keep your bathroom at a closer temperature to the rest of your home. However, in most situations, you don’t want to install ventilation yourself – simply because it may be regulated by local law. You can always check and decide to DIY or not based on those regulations. In the case that you do it yourself, make sure you install the vent as close as possible to the source of the hot water and make sure you vent it properly, outside. 

Good ventilation can be difficult to install, especially if your bathroom is not near and exterior wall. Therefore, you might have to run a duct some way inside the ceiling. You’ll also have to use appropriate fans on each end to ensure water does not collect inside that duct. 

FAQs

Fixing condensation issues can be tricky. If you still have more questions, hopefully these related questions help. 

Will a dehumidifier get rid of damp?

Dehumidifiers won’t solve damp problems. If your home is damp enough that the walls are sweating, you need more than a humidifier. However, once you do install ventilation or insulation, a dehumidifier can help you to dry everything out. Dehumidifiers are primarily intended for light humidity regulation, which can help. But, it definitely won’t actually solve the problem. 

Why do my walls sweat yellow? 

Yellow sweat or condensation on walls normally relates to mineral buildup. This is especially common if you shower and condensation builds up on the walls. The minerals in the water you shower with stay in the steam. Then, the steam collects on the walls as condensation. As it turns back into water, the minerals stain the paper – causing your walls to sweat yellow. Eventually, you could get yellow or even brown drips down the wall. 

The solution is, of course, to fix the condensation issue. But, you can also reduce the amount of yellow in the condensation by using a mineral filter on your shower. We’d highly recommend the first option instead, as that will also prevent mold and water damage to the walls. 

Summary

There are two primary reasons your bathroom walls are sweating or condensation. Fixing those reasons is important before you take steps to clean stains, otherwise the stains will come back. However, you can easily clean off most stains with bleach or ammonia and borax.

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