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Extractor fan into loft space, problem?

A couple of months ago I used an electrician to install an extractor fan in the bathroom. When he came round to give me a quote he stated that he would drill through the wall to the outside to install the fan. When I accepted their offer and they came to install it, he changed his mind and said he would drill the hole in the ceiling up into the loft. Not knowing any better I let him go ahead with this. Now I have bad condensation on the loft felt and after much research have found you should never have a fan going into the loft space. Is this the case? Any advice would be much appreciated.

1 Answer from a MyBuilder Electrician

Best Answer

Vix123, bathroom fans should wherever possible be ducted to the outside taking the shortest possible route. In most cases this is directly through the wall, where an outdoor grille is fitted.

You are right to be concerned, as your fan is simply moving the humid air from the bathroom to the cold loft, where it is condesnsing and this is not likely to be doing your roof joists any good at all.

Where fans have to be ducted up into the loft, there should be a 100mm flexible duct run from the van all the wall to the either the soffit (under the gutter or to some form of exit point out of the roof, e.g. through the tiles.

It sounds like you hired a cowboy on this occasion. Did you get an electrical certificate for the work? and was the completed fan installation notified to your local authority under part P of the building regulations? Only if the work has not been notified, then its been done illegally and you could face a fine of up to £5000. Householders must ensure that they only hire competent electricians who can prove that they are members of one of the three goverment approved Part P schemes; e.g. NICEIC, etc.

Click on the link below for more information on part p of the building regulations;

Unfortuantely it maybe the case that you will have to pay to get a part P registered electrician in and refit the fan properly and issue you with all the correct paperwork.


Answered 22nd Jan 2013

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