Extractor fan in bathroom causing mould in loft

lizzyshep

We bought a house last year and the bathroom has no window, so there is an extractor fan which vents into the loft space.

We had the fan replaced shortly after we moved in last May, and we had the loft insulated about 5 months ago. Today the insulators came back to top up the insulation (it hadn't been laid thick enough the first time) and the installer showed me that the extractor fan was causing moisture in the loft - the beams had mould on them.

Now he's pointed it out, it seems obvious the fan shouldn't vent into the loft, but the question is what we do about it! He said we need to get something to vent from the fan out of the roof, we should also get vents put into the roof. He said we need a builder for this.

Is he correct? And any ideas what this will cost? I am going to call the electrician who put in the fan, but was hoping anyone on here might have advice too. Thanks :-)

jbainbridge

If the bathroom has an external wall - a fan in that might be the answer.

The roof fan should be attached to a hose going to a 'tile vent'. The warm moist air from the bathroom is condensing on the cold roof ... not good!

Finally your roof space should be open in some way. Is it? They are usually vented where the roof meets the house wall ... have a look. Ventilation will stop the roof timbers rotting.

lizzyshep

No, there's no external wall in the bathroom. As far as I know, there is ventilation in the eaves of the loft - I'm not sure how I'd look for this to check?

lizzyshep

I have also posted this question on a diy forum, and was told our electrician is to blame, he should have told us it needed venting through the roof. Is this correct?

fluffpot

yes - there is no way that a fan should vent into the loft space - it needs to go outside - the first electrician didn't do the job correctly

lizzyshep

I think that the first fan was installed by the previous owner (a builder) who I think did a lot of DIY, and some not that well!

But our electrician should have realised it was a problem and told us, is that right? I am wondering if we can get him round to sort it out free of charge, or we need to pay someone to do it.

The electrician we used is a member of NAPIT, and I thought their standards were quite stringent, so he should have known it was a problem, shouldn't he? We employed him to come and look at the house and tell us what needed doing, he said the bathroom fan needed replacing, surely he should have known it needed venting to outside?

Quiet_Spark

lizzyshep wrote: »

But our electrician should have realised it was a problem and told us, is that right?

If you asked the sparks to replace the fan and ensure that it was venting correctly, then he has failed in his job.
However I'm guessing you only asked him to replace the fan, and that is exactly what he has done and you have paid for.

lizzyshep

Quiet_Spark wrote: »

If you asked the sparks to replace the fan and ensure that it was venting correctly, then he has failed in his job.
However I'm guessing you only asked him to replace the fan, and that is exactly what he has done and you have paid for.

Not quite. We asked him to come round and look at the house which we'd just bought, and tell us what needed doing. One of the jobs he identified was that the extractor fan needed replacing - he said the one that was there wasn't suitable for the job.

But it seems to me we're splitting hairs here - if he knew it should be venting outside, then he should have told us!

fto

Not his fault.
He changed the fan for a better one...He was not to know it was venting into the loft.
Its like a plumber replacing a Tap on your sink & you blaming him for the waste being done wrong.

Dave_J_3

fto wrote: »

Not his fault.
He changed the fan for a better one...He was not to know it was venting into the loft.
Its like a plumber replacing a Tap on your sink & you blaming him for the waste being done wrong.

hmmm i kinda disagree there. He would have known where it was venting as when he installed he would have had to connect up a flex hose etc to the rear of the fan before he fitted, or after depending on install. If there was no hose then you got to question why not? Even going through a wall there should be a hose of duct to stop damp in the cavity.
Its not his fault there is not one, he should have told you, but charged accordingly for parts and labour to fix correctly.

lizzyshep

So - just spoke to the electrician. He said he didn't realise the fan wasn't vented properly as he didn't go up in the loft - he just replaced the fan because it wasn't the right type.

Whether or not it was his fault, I need to get this sorted out, so what type of tradesman do I need?