Use a Squeegee

So what is the best way to inspect and protect? It's actually at the end of each shower or bath. Wipe down the walls after each shower, regardless of the type of wall system you have. A $2 squeegee will take most of the water off the walls, prevent that build-up of mold and yucky stuff on your grout work and caulking, and reduce the likelihood of failure. So it's a no brainer! 

How does the mold on the grout form? It arises after you turn the shower off. Why? There is no longer any momentum for the water on the walls to run down, so it goes slowly. The water moves so slowly that it stops when it hits the caulking and doesn't have the momentum to keep going into the tub. The water then sits there with some soap scum and skin cells, and it's a little party zone for mold—and that's what takes hold. By wiping down the walls, you remove the water that can help create that habitat. And, more importantly, you are using a chemical-free method to control mold in the bathtub.

Moisture Control in the Bathroom

Once you have tried to limit the water from remaining on bathroom surfaces, it's essential to recognize that moisture is in the air too. How can you control that? Read on.

Bathroom Fans to Control Moisture

Bathroom fans are critical in moving moist air out of a house. If moisture builds up, especially in the warm weather, it creates a potential for mold growth within the space and beyond. If there is laundry in the bathroom or if it is connected directly to a bedroom, it will create a higher potential for mold growth. This risk occurs as the dust and debris of clothes provide the food source and home for mold, with the high moisture content in the air being absorbed by the clothing.

Ideally, bathroom fans are hardwired into the switch to operate at all times and cannot be turned off. Alternatively, fans that have moisture or motion settings are also great options. It is important to get a quiet fan so that no notice is taken when it is running. Fans are rated in "sones" for noise, and the quieter the fan, the better. You can also find some that have external motors, which can be installed in the attic to reduce noise in the bathroom.

According to Canada Mortgage and Housing Corporation, bathroom fans should hold a piece of paper with the draw. This test indicates that the fan has the capability of removing the moisture in an average-sized small bathroom. The fan housing should also be airtight to the drywall, meaning the metal box should be sealed to the drywall with tape or spray foam. Otherwise, the fan could be drawing air from the attic into the bathroom. If this occurs, the efficiency of the unit is compromised, and air quality will be impacted. Consider an Energy Star rated bathroom exhaust fan to ensure you consume the least amount of energy during operation.

The final detail is to ensure that your bathroom exhaust fan exhausts outside and not into an attic or wall cavity. If you skip this step, it can lead to excessive moisture in your attic and mold growth. The ductwork needs to be insulated, tight, ideally solid, not flex duct, and taped at both ends and any elbows or joints. If exhausting through the roof, use an insulated duct. If exhausting out the soffit, make sure the ductwork is below the insulation. 

Why not just natural ventilation? Many people will only open a window and consider that to be enough to control moisture. That might work if the window faces the house's downwind side, meaning it will draw the air out. My bathroom window faces west, towards our prevailing winds, so it just blows air in, not out, and doesn't offer much moisture exhaust. Ensure your "natural solution" is, in fact, a solution.