Under stairs toilet, no space for fan extraction! (2025)

Just converting the tiny utility room under the stairs for a small downstairs toilet but no space to fit a extractor fan as there is no outside wall that for extraction.

The builder, who is a plumber has no idea how do it. I looked on the internet and read people using flexible ducting with a shower type fan, is that how you normally do it.

Boilerman2 said:

With ducting and a suitably high performance fan ANYTHING is possible, if you want that space to be a WC you will have to!

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Thanks for the reply.

How do you do it, that's the question.

It's a terraced house, so can't expel air near the wall and has no windows.

The builder has a dug long path for the soil pipe to join the main drain in the garden. What sort of ducting is suitable, flexible or rigid for long term use.

Piece of cake. Lots of ducting available to go on the wall, under the floor, in the floor void above etc.
You'll need a centifugal pump to get enough pressure but they're common.

Google it - eg http://www.bes.co.uk/products/180.asp

You need the right m³/hr so make sure there's somewhere for the air to get IN to replace what's going out or nothing will move. Vent in the door is the usual.

eastender3 said:

Just converting the tiny utility room under the stairs for a small downstairs toilet but no space to fit a extractor fan as there is no outside wall that for extraction.

The builder, who is a plumber has no idea how do it. I looked on the internet and read people using flexible ducting with a shower type fan, is that how you normally do it.

Click to expand...

Just get a fan and stick it on the wall - no electric/duct nothing - they do it with burglar alarms There is no`wt like a bit of kid- ology

Thomas Dudley Panfan:
http://www.thomasdudley.co.uk/specification/panfan.asp

Although, it states it is for use with their Vantage cistern.

you could use one of these
http://www.approvedgasmasks.com/images/evo5000-mask.jpg

ChrisR said:

Piece of cake. Lots of ducting available to go on the wall, under the floor, in the floor void above etc.
You'll need a centifugal pump to get enough pressure but they're common.

Google it - eg http://www.bes.co.uk/products/180.asp

You need the right m³/hr so make sure there's somewhere for the air to get IN to replace what's going out or nothing will move. Vent in the door is the usual.

Click to expand...

My builder has now started work on our downstairs toilet. He has bought 4" round pipes that he is going to duct through our floorboards and exit beside the front door.

What type of extractor fan would be suitable, preferably from screwfix
website.

You mentioned earlier about centifugal pump, to get enough pressure, so we'll look at screw fix, as I want it now.

Vent in the door, the builder has not mentioned it. Does it mean that he has cut the door, which is newly fitted by him, to allow air inside the toilet? I'll ask him cut from below and leave a half an inch, to for air to enter, instead of fitting those ugly fixed vents in the new door.

I'm worried about draft entering from 4" exit hole that he cut out.

I'm stuck as I hired this foreign builder who speak little english and probably has now knowledge about extraction in confined space!

He has fitted the extractor fan with the light switch, so if anyone goes for a pee or brush his/her teeth the bloody fan comes on, is there a simpler way of having separate switch for fan and light, however he has done the wall tiling, so wonder if it's too late!

I like to separate switch for our downstairs toilet for fan and light, as he hasn't done wiring yet and not tiled it.

eastender3 said:

He has fitted the extractor fan with the light switch, so if anyone goes for a pee or brush his/her teeth the bloody fan comes on, is there a simpler way of having separate switch for fan and light, however he has done the wall tiling, so wonder if it's too late!

I like to separate switch for our downstairs toilet for fan and light, as he hasn't done wiring yet and not tiled it.

Click to expand...

Given the room has no opening window, it is a requirement that the fan comes on with the light for building regulations.