Why is My Bathroom Mirror Steaming Up?

The bathroom mirrors often steam up when you take baths in a shower or bathtub and become invisible. You cannot see the mirror or shave after bathing because of its poor visibility.

Why is My Bathroom Mirror Steaming Up? Your bathroom mirror is steaming up because of condensation, poor ventilation, cold walls, absence of anti-fog coating, mirrors without demisting pads, and poor covering. Moreover, fogging is due to damaged fogless mirrors, weather changes, and leaky plumbing systems.

You can use different techniques to quickly defog the mirror because you cannot take a bath with opened windows on cold days.

Causes Solutions
Condensation Run cold water from showers or use a hairdryer
Poor ventilation Open windows and turn on exhaust fans
Cold walls Treat with soap
Absence of anti-fog coatings Use glycerin or commercial defogging sprays
Mirrors without demisting pad Install demister pad on backside
Damaged coating of fogless mirrors Seal with vinegar and shampoo
Poor installation of extractor fans Reinstall the extractor fans
Leaky plumbing system Cover the mirror with a cloth


Condensation reactions occur when cold surfaces come in contact with a hot and humid environment. It condenses the water in the form of steam, which can lead to a blur effect and poor visibility.

The fogging up comes when the cold surface of the bathroom mirror comes in contact with the hot environment. For example, the issue comes in winter when you take a bath with warm water.

The interior’s temperature rises more than the cold glass surface. Moreover, the problem also comes when you turn on the shower and bathtubs.

The warm water from these areas causes the fogging-up problem. You can fix it by running the cold water from the showers to maintain the temperature.

You can also clear the steam by treating it with a hairdryer because heat from these devices evaporates the fog.

Poor ventilation

Mirrors also steam up due to poor ventilation in the bathroom because of the absence of windows and open areas to balance the temperature.

The long-term running of hot water from the showers makes the surroundings warm and causes problems. You can face it when toilets are not equipped with exhaust fans to remove steam.

Sometimes the exhaust fans are present but are not working correctly to remove steam. Moreover, these cannot function properly if their vents are clogged with dust and debris.

Coat the glass surface with shaving cream and wipe it off with a dry cloth. The shaving cream creates a barrier and prevents condensed water from settling on cold surfaces.

Install the exhaust fans if these are not present for better air circulation.

Cold walls

The cold wall changes the temperature of the mirror mounted on them. As a result, the warm water from the surroundings comes to the cold surface, leading to the fogging issue.

It is common when bathroom walls are poorly or non-insulated. These cannot maintain the temperature in the winter and keep them warm.

Moreover, the issue arises when people live in small apartments in basements. The temperature is lower in these areas and making the conditions cold.

Moreover, the cold weather and poorly insulated walls trigger the problem. Treat the glass surface with soap. Rub the soap and wipe it off with a cloth to create a barrier against steam settling.

Absence of anti-fog coatings

Some mirrors are coated with anti-fog coatings that act as barriers, and steam cannot come on them. These are specialized for installation in bathrooms to keep them safe and reduce blurring issues.

Most people do not know about these types and simply select the chrome-based material for an installation.

These do not contain any protective coating that can prevent fogging issues. The absence of a chemical-based protective coating causes the humidity to come on them.

I use commercial defogging solutions. Select these solutions from the market, spray them on the glass surface, and then buff them with a lint-free cloth.

These can last for months and act as the barrier between the glass material and water. Moreover, you can also use glycerin by diluting it with water.

Mirrors without demisting pad

Most of the mirrors come up with the demist pads in the market. The primary function of the demist pad is to provide heat to cold surfaces and reduce condensation issues.

These are present on their backside and provide mild heat so they cannot collect water vapors. Many times, these demisters become faulty and cannot provide heat.

These become faulty due to electrical switches and the problem with power outlets. Moreover, many people do not install them on the mirror’s backside.

After inspecting their location, you can stop the condensation reaction by installing the demister pads on the backside of your existing mirrors.

Damaged coating of fogless mirrors

The fogless bathroom mirrors contain chemical-based sealant coatings to prevent fogging issues. However, these types require more maintenance and cleaning to keep them clean and clear.

The fogless layer can get damaged when you do not remove it from the walls or vanity side after use. In addition, excessive water splashes can damage their sealant layer.

Moreover, poor cleaning and excessive use of cleaners on their surface damage their coatings. A clear polyester film is applied to them to prevent steam formation.

The layer can also damage over time and cause this issue. You cannot fix the damaged sealant layer of these glass surfaces, and replacing them with a new one is better.

You can temporarily treat it with vinegar, but it is not a long-lasting solution. It is also better to apply shampoo on them and remove it with a paper towel to create a barrier.

Poor installation of extractor fans

The main function of the extractor fan is to remove the steam from the bathrooms and make the interior clean and fresh. Sometimes these are not installed properly and cause mirrors to fog up.

These are installed on the poor side and cause steam from the outer side to come inside and blur the glass material.

Sometimes these become faulty and cannot clear the fog from the inner side after showering with warm water. It is necessary to reposition the extractor fans when these are present on the wrong side and draw heat from other sources, like the cooking area.

You can call the mechanic for their reinstallation at the correct place and better functioning.

Leaky plumbing system

Many people complain that the bathroom mirrors fog up after some time, and they are not using warm water for showers.

Moreover, you can see steam on the glass surfaces when bathtubs are not used. The issue comes due to a poor plumbing system and leakage of water from the heating pipes.

The water leakage from the pipes’ poor connection causes this problem. In addition, the water leakage from the hot faucets can blur their surface, and you cannot see anything.

It is better to inspect the plumbing system properly. Tighten the loose connections and prevent water leakage in bathrooms.

People often cannot find leakage in the plumbing system, and you can cover the glass with a cloth when these are not in use.

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