Dos and Don'ts of Installing a Bathroom Exhaust Fan

A bathroom exhaust fan can be the cure to mold formation and excess humidity in your bathroom. Some of the cheaper exhaust fans serve one function—to act as fan-powered vents. However, the more expensive models may also contain allergen-reducing filters. This is particularly good if a member of your family has a history of asthma. It is not uncommon to complete the exhaust fan’s installation and find out that it is somehow non-functional. Here is a list of Dos and Don’ts to make sure you get it right the first time round!


Before even purchasing an exhaust fan, determine which model you would need for your bathroom. The larger the bathroom or the more frequently it is used, the more powerful the exhaust fan should be. Always evaluate your options before you reach for your wallet!

Use a small handsaw to cut a hole in the roof of your bathroom, but remember to plan its diameter from beforehand. The size should suffice the length of the exhaust fan itself. Cut 1/8 inch from the side of the template edge. This will give you space to remove more material if needed in the future.

Install the exhaust duct that came along with the whole package. The duct should pass from the ceiling of your bathroom, across the attic to your roof soffit that leads outside. Make sure that the duct is connected completely and adequately insulated. If you cannot lead the duct to your roof, you can always position it in a way to lead outside from a side wall. Remember that the vent should also be included in your kit, so ask the sales person if you cannot find it.


Never start this project before you are 100 percent certain that the flow of electricity to your bathroom has been cut via the breaker box or main power supply. Electrocution when undergoing such projects is not unheard of.

You should never attempt to connect the bathroom exhaust fan without a sound knowledge of your home’s electrical wiring system. Special importance should be given to the wiring of the bathroom ceiling light. This is the ideal location to wire your new exhaust fan. Each fan should have a wire scheme, which would explain in detail the exact procedure of wiring.

Remain unprotected at your own risk! When working with electricity, rubber gloves are advisable. Eye protection could avoid horrible injuries, especially as the majority of the work has to be done overhead. Extra caution should be practiced when using the carpentry tools. Always work when you feel fully focused.

Installing an exhaust fan should take you a few hours at most. It is not the easiest of projects. Always consult a professional if you are unsure about something. By installing a bathroom exhaust fan you will be saving money in the long run. The damage caused by mould and other minute organisms can run into thousands of dollars. As the old saying goes; 'prevention is better than cure'.