Humidity in bathrooms | Inquirer Business
Green Architrends

Humidity in bathrooms

/ 08:24 PM August 09, 2013

The bathroom is one of the most important and frequently used areas of the building. It poses specific safety concerns that are best addressed as early as the design stage. The primary issue would be the presence of moisture that can have far-reaching effects on the longevity of the bathroom area and its immediate surrounding rooms, as well as adverse effects on the health of the people using the bathroom.

One of the lesser-known aspects of green architecture is the focus on indoor air quality for specific rooms in the building. Given that each room may have very specific uses, indoor air quality specifications to ensure occupant well-being vary for each room.


Presence of health hazards

The biggest problem with bathrooms is the high humidity level. Humidity is simply the amount of water vapor in the air. Warm air holds more humidity than cold air. These may be adversely affected in the bathroom by the presence of microbial hazards that grow in damp and dark areas, such as poorly designed bathrooms.


Some microbes form part of everyday household dust; these can already trigger allergic or other respiratory problems when these accumulate in sufficiently large quantities. If lately one has been experiencing chronic coughs, migraines, frequent sneezing and difficulty breathing, check if the bathroom that one uses has good indoor air quality.

For bigger bathrooms it is recommended to have a bathroom fan, which is an exhaust fan that pulls excess moisture away from the  interior to be vented outside the building. In this way, the humidity and moisture inside the bathroom reduce the risk of growth of mold. However, one must check that the bathroom fan is strong enough to pull moisture outside the bathroom, and a simple way to test this is by holding up a tissue to the fan. If the tissue falls down, the fan is not strong enough.

Impact on other rooms

Sometimes bathroom moisture is high, simply because of the presence of undetected or neglected leaks, such as from water closets or hard-to-reach  pipes. Moisture in the bathroom can find places to seep into, such as cavities in the roofs or floors, and work their way into adjacent rooms. This is usually how indoor leaks occur.

Having bathroom fans’ exhaust vent into attics or other rooms inside the building can cause molds to form in them and wood to rot. Thus it is best for exhaust vents to be directed outside the building.

Humidity levels in your home

To find out if humidity levels in your home is abnormally high, there are a few inexpensive tests that you can make.


Check your walls and windows. Windows that are constantly fogging up or  moisture buildup on ceilings  may be telltale signs of high humidity levels in your home. Check closets and bathrooms if they have molds, which indicate an extremely high humidity level.

Design prescriptions

Wet surfaces in the bathroom should be designed deliberately and with the correct properties. The areas that normally get wet in a shower area should be finished with tiles and/or glass surfaces that will block water from splashing onto adjacent surfaces in the bathroom.

The height of the nonporous surfaces should be as high as the height of the average shower user, but the entire height of the shower area should not be made with  tiles/glass entirely since these can cause the humidity to accumulate in the bathroom. Instead, a porous material such as concrete should be used for the upper walls and ceiling of a shower area so that moisture can dissipate. Strategically located vents/windows will also be helpful in reducing the enclosure of humidity in the shower area.

Flooring is usually made of tiles, which can seal surfaces below from moisture. For occupant safety however, it would be best to have nonslip surfaces like rubber mats to reduce the  risk of slipping, especially for children and elderly users.

As much as possible, adequate natural ventilation and daylighting should be available in the bathroom, which can help reduce the spread of molds and mildew, as well as give the bathroom a bright and healthy atmosphere.

I have often renovated old houses and buildings with bathrooms located deep inside the structure with no direct access to natural light and air. This is obviously the result of poor planning on the part of the designer, who neglected the importance of the bathroom’s proximity to sunlight.

One way to address humidity concerns in bathrooms is through dehumidifiers like those  in many countries.

According to my colleague, engineer Jojo Castro, secretary of the Philippine Green Building Initiative and past president of the American Society of Heating, Refrigerating and Air-conditioning Philippines, “dehumidifiers for homes are not sold here.

Many are selling humidifiers or evaporative air coolers which they claim are portable air-conditioners. This is not accurate. This type of equipment is not suited for a hot and humid country like the Philippines because it increases the humidity level and cooling load of air conditioners. Water added in this unit may not always be clean, thus increasing the risk of respiratory diseases like the Legionnaire’s disease.

One possible solution is by using energy recovery units to maintain better humidity levels in homes. This is just a ventilation equipment (an air-conditioning unit) that brings in treated fresh air into the room and exhausts contaminated air.

Another way is the use of roof ventilators to constantly exhaust hot air caused by the roofs’ exposure  to sunlight, especially  if there is no air-conditioning system in the house. Exhaust fans can also be installed in walls to suck out hot air. while bringing in fresh air through infiltration. This is an alternative for those who do not want to use electric fans.”

For comments or inquiries, e-mail [email protected]

Your subscription could not be saved. Please try again.
Your subscription has been successful.

Subscribe to our daily newsletter

By providing an email address. I agree to the Terms of Use and acknowledge that I have read the Privacy Policy.

Read Next
Don't miss out on the latest news and information.

Subscribe to INQUIRER PLUS to get access to The Philippine Daily Inquirer & other 70+ titles, share up to 5 gadgets, listen to the news, download as early as 4am & share articles on social media. Call 896 6000.

TAGS: Amado de Jesus, bathrooms, column, humidity, property
For feedback, complaints, or inquiries, contact us.
Your subscription could not be saved. Please try again.
Your subscription has been successful.

Curated business news

By providing an email address. I agree to the Terms of Use and acknowledge that I have read the Privacy Policy.

© Copyright 1997-2023 | All Rights Reserved

We use cookies to ensure you get the best experience on our website. By continuing, you are agreeing to our use of cookies. To find out more, please click this link.