By Kerry Hale

How To Install A Bathroom Extractor Fan

  • Friday 25 November 2022
  • 5 minute read

If you’re looking for ways to keep your bathroom ventilated, consider installing an extractor fan

Our guide includes everything you need to know, from the benefits of bathroom extractor fans to the different types available and how to fit an extractor fan.

Why install an extractor fan?

Bathroom extractor fans help remove moisture from the air, which will otherwise cause damp and mould to build up. In the UK, all bathrooms must be ventilated by either an extractor fan or a window. To combat mould and mildew in your bathroom, it’s worth installing an extractor fan and using the windows for ventilation.

Choosing the right extractor fan

There are three types of extractor fans available: axial, centrifugal and inline. Discover how each type works to find the right solution for your bathroom.

Axial extractor fans

Axial extractor fans can be fitted to an external wall, allowing moisture and air to escape outside. They can also be installed in some windows.

Centrifugal extractor fans

Centrifugal extractor fans are often fitted to ceilings and are ideal for en-suites or bathrooms that don’t have an external wall. The air is ducted a short distance to an exterior vent in the roof eaves or a wall.

Inline extractor fans

Like centrifugal fans, inline extractor fans are fitted to the ceiling with up to 40 metres of ducting distance.

Bathroom extractor fan installation

Discover our top tips for installing or replacing a bathroom extractor fan from the tools you’ll need to step-by-step instructions.

What you’ll need

To install a bathroom extractor fan, you’ll need the following tools and equipment:

  • Saw
  • Drill and suitable drill bits
  • Screwdriver
  • Stud detector
  • Pencil
  • Grill cover and fittings
  • Screws
  • Wall plugs
  • Flexible ducting
  • Step ladder

How to fit a bathroom extractor fan

When fitting a new centrifugal or inline extractor fan to the ceiling, follow these steps:

  1. Before drilling, use a stud detector to check the ceiling for supporting beams, wires or pipes. Make sure there is enough room in the loft, and you can access the area to remove any obstructions like insulation.
  2. Use a pencil to mark the area where you want to install your extractor fan, including the circular vent.
  3. Drill a hole in the circle’s outline, then use a pad saw to cut out the whole shape. Remove any excess material from the hole you’ve cut.
  4. Secure the fittings to the back of the vent that will connect to the ducting pipe in the loft. Once you’re happy with the placement, use a pencil to mark where the screw holes will go when attaching the vent to the ceiling.
  5. Drill the marked holes and secure the vent using wall plugs, screws and a screwdriver.
  6. Next, install the fan in the loft. It should be fitted horizontally to the loft floor and needs screwing in..
  7. Attach the ducting pipe to the ceiling vent at one end and the extractor fan at the other. On the other side of the fan, secure ducting to the exterior ventilation (like roof eaves or a wall vent).
  8. Once all the components are in place, the electrical connections can be made. A qualified electrician must do this to ensure the safety of your extractor fan. The bathroom light switch or a separate control can operate your extractor fan.
  9. When the electrical work is completed, secure the grill over the vent in the bathroom ceiling and replace any loft insulation you’ve moved.

When fitting a new axial extractor fan to an external wall, the steps are mostly the same, however:

  • Ensure the fan isn’t obstructed by external pipes and doesn’t sit below a window.
  • To make the hole in the wall, drill numerous holes around the circle you’ve marked for the vent, then use a hammer and chisel to remove the brick or stone.
  • The ducting pipe should sit flush between the internal and external walls and be fitted at a downward angle.
  • Grill covers should be placed horizontally to keep the rain out.

Looking for more handy guides to DIY bathroom installations? Visit our blog’s ‘how to’ section for more help and advice.

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