What is the best way to install bathroom extractor fan

[TanDiy]

Hi, Have fitted a shower over our bath and was hoping that the window would be ok for ventilation. Unfortunately the walls are getting wet with condensation and I think we need further ventilation. I have been looking at extractor fans and would really appreciate some advice on this.

(1) Do you normally fix these to the wall or should they go on the ceiling. If they are on the ceiling then I guess we have to run a flue up and out the roof which sounds like a lot of work (and expensive!)

(2) Are these just wired in to the lighting circuit or do they need their own supply. Also, is this something we can fit or do the regulations require that this is done by a professional.

(3) Finally, I have found some fans that automatically switch on when the humidity gets bad - are these any good or is it best to stay with a unit that can be turned on and off with a pull cord.

Thank you very much for any assistance and advice.

 

[pjcomp]

If you fix an extractor to the wall you need to drill a 4-inch hole through the wall for the air to go out. Going through the ceiling and out through a vent tile is another option - the ceiling option makes less mess but price-wise they work out broadly similar. Assuming you've got a loft space available the wiring's easier with a ceiling job as well.

You can wire them off the lighting circuit, the choice then is whether it switches on/off with the light or it's own switch. Go with the light option, it only works if someone uses the light (not always the case in daylight or summer); if you have a separate switch the user has to remember to turn it on or off. You pays your money, takes your choise.

The humidistat option means the moisture level controls the fan and should be best at reducing your condensation. You'll probably need to experiment with the settings on it get it right for you and so it doesn't run non-stop.

Being a bathroom the work will also be notifiable to the local council under Part P.

PJ

 

[TanDiy]

Many thanks for the info. I need to look up the regulations. I think this means that I have to pay a profressional electrician to do the work who can then certify the work. If I do the work myself I am guessing I have to pay a fee to the council which probably makes it uneconomical.

Thanks again.

 

[ban-all-sheds]

//www.diynot.com/wiki/electrics:part-p

Also note that if you take the fan duct through an unheated loft you'll get condensation problems, so you'll need to look into lagging it, and routing it so that any condensation does not run back into the fan and/or install a condensation trap.

 

[TanDiy]

Many thanks for the info - I am trying to decide whether to go in the loft or straight through the wall. One company yesterday told me they can no longer use ladders due to Health & Safety and that I will have to pay for scaffolding so I need to find out what will be involved. I am thinking it might be less hassle to remove the shower and stick with baths !!!

Thanks again for the info.

 

[echoes]

If it's outside bathroom zone 2, it's not necessarily notifiable.

 

[riveralt]

This will come under the work at height regulations (2007 amendment) which requires those working at any height where there is likely to be injury from a fall to conduct a risk assessment and put plans in place to minimise that risk.

Working from a ladder is allowed provided that ladder is properly secured, but it is considered unsafe to work from a fixed ladder for more than a set time, 10 minutes I think. Using a core drill to neatly cut the outside brick hole for the extractor fan tubing will normally take considerably longer than that and when coupled with the weight of the SDS and core drill bit means that most work of this type needs to be conducted on properly fitted scaffold.

You could drill from the inside to out but you tend not to get a good clean cut that way.

Cutting either way you will still need to fix the outside vent to the wall by means of drill and plug.

When thinking of the overall cost of doing it yourself you will have to take into account the hire of the scaffolding, the hire of the SDS drill if you don't have one and the purchase of the core drill.
Get a few quotes and then compare.