UKC

I was wondering if anyone on here might have any experience of this.

We had a new small ensuite with a shower put in a few months ago and for various reasons it wasn't possible to put an extractor fan in the wall. The guy advised taking the steam/moisture out via the loft and eaves with a flexi pipe. He employed some electrician subcontractors to actually do that bit of work.

I was up in the loft a few weeks ago to put some new insulation down and noticed they hadn't properly routed the pipe from the extractor fan out, so it was just discharging into the loft. I was pretty concerned about this as it's an old roof and a damp problem up there could be very problematic. The electricians came back round to fix it this week but all they have done is push the end of the pipe up to near the opening in the eaves. The pipe is 4 inch diameter I think and the gap in the eaves is a rectangular opening which he said was approx 3*9cm, ie quite a bit smaller.

I think this will probably still result in quite a bit of steam/moisture discharging into the loft. The electricians were adamant that the air currents outside will draw all the steam out, there will be more damp in the loft from rain drips through the slates anyway (admittedly they are not perfect) and that I needn't worry about it as long as the loft is ventilated (which it obviously is.) They said that they had done many older houses like this.

Does anyone with experience have a view on this? Is this the normal way to do things or should they have fitted some sort of adaptor piece to make sure that all of the steam/moisture got out via the eaves properly? He claimed the only alternative was to replace a slate with a special venting roof tile.

Thanks

In reply to Si dH:

SOunds highly dubious to me.   Some guidance here

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/...

Venting moist warm air into a cold, dryish roof-space is asking for trouble isn't it?  Moisture will condense on surfaces which could lead to rot, mould etc. etc.

In reply to Si dH:

My vents for bathroom and for shower, go vertically through the loft and out the roof through a gasket that fits under the slates. There is a cap to stop the rain.

In reply to Si dH:

Mine was the same when I moved in. Extractor fan in en suite ceiling venting into loft. Silly as there was a tile vent nearby but not connected. Loft timbers were getting mouldy in that area. Fitted ducting to the tile vent and all OK now. Don't leave it like it is. Mine also caused damp on some wiring leading to corrosion of a joint and failing lights. 

In reply to MG:

More than dubious, plain wrong , it needs to be vented to outside.

The link also points out that the water that will condense in the duct needs to be able to drain outside. Ie no wavy ducting,  up and down , that will trap condensation, specific diagram in the link.

In reply to Si dH:

I'll add to the 'dubious'. I vented both the existing bathroom (which, like yours, just vented to the loft) and the en-suite we put in out through the gable ends of the loft. I had to hire a decent core drill to cut the holes for the ducting, but it wasn't a particularly difficult job.

In reply to Si dH:

Ours goes up into the loft then out through a flappy vent in the end wall.

Warm humid air in the loft is bad. A badly fitting loft hatch cover caused me disproportionate condensation problems. I damn sure wouldn't leave a shower steaming it up.

In reply to Si dH:we have a ceiling extractor that goes up through loft space through a flexible pipe to a soffit vent adapter - fairly simple set up like the image in this link, think this is what you would need to keep the damp extractor exhaust out of the loft space  

https://www.electrical2go.co.uk/media/catalog/product/cache/1e532b06ab879cf...

In reply to Si dH:

There are 2 approaches to a lot of stuff

1)"Meh..." it's probably good enough

2) Building regs

I advise you find a good builder willing to follow the second approach, preferably without you having to insist

.

In reply to Si dH:

Definitely dubious.  I did something similar, but hooked it up to a vent tile which has a specific adaptor to allow the pipe to connect to it.  You can check the spec of the fan (which btw, will almost certainly not be powerful enough) and the spec of the tile to make sure it'll vent enough.

I would strongly recommend removing whatever crappy fan has been installed and putting a proper fan into the roofspace.  That way you can get a fan which will actually be powerful and quiet.  I can't remember what I got, but it cost £100 odd, so you're looking at that an up.  It will also mean that you'll actually vent your shower room quickly, which when you're trying to get the family showered in the morning, will help.

We had loads of condensation issues in the previous house and we put a lot of vent tiles in our roof.  ISTR that your house is of a similar vintage, so you may want to consider a few extra vent tiles.  They're quite cheap to buy and fit, so chuck a couple in, see how it goes.  Add more as needed.

Message me on FB if you want links.

In reply to Si dH:

I had a similar setup in a new build house which seemed wrong. Other than moving the end of the duct to near a vented section of the eaves, I didn’t do anything about it and didn’t notice any issues in the 14 years I stayed in the house. That said, as someone else up thread has done fitting a duct cover on the eaves soffit board wouldn’t be a massive job.

In reply to Si dH:

Thanks everyone. Not what I was hoping but what I was expecting and it's certainly conclusive. I'll have to get someone new to come and look at it as I don't trust the same guys to do a good job if I persuaded them to come back.

Unfortunately I think it's going to mean either a roof tile or ripping the fan and ducting out completely and trying again to find a way to vent through the wall (there is only width for a 2 inch vent because the wall has a massive window* in it, which is why we didn't do that to start with.) The problem with the roof tile option is that any work on the roof requires a scaffold, as it's too high for a ladder. So that'll be several hundred £ if I'm lucky. It might be possible to take it out via the side wall instead but that would be quite a long run of ducting which the gov.uk link above advises against.

* The good thing is we can of course open the window when using the shower for now.

In reply to Si dH:

Did you consider a window exhaust fan? 

In reply to RobAJones:

No. But...huge expensive sash window. So probably not feasible.

In reply to Si dH:

Oh. This might be an irritating question, but in that case why bother? I thought people only fitted extractors if there's no or not enough opening window.

In reply to Longsufferingropeholder:

The guys doing the overall ensuite job seemed sure it was needed. There is quite a bit of volume for steam/moisture to collect in above the window so maybe that was the thinking. And obviously it's cold for opening the window in winter, although that wouldn't bother me so much, maybe my wife. Maybe you're right.

In reply to Si dH:

We did the opposite, but as it was just the glass that needed replacing it was surprisingly reasonable.

Not sure if they do them in the size you would need, aesthetically not to everyone's tastes, and security might be a concern but if you have sash windows, there are fan units that simply fit into slightly open sash windows. 

In reply to Si dH:

I was surprised how simple and cheap mine were.  Make hole in ceiling, make aligned hole in roof, insert single rigid (110mm ?) pipe, feed gasket down pipe, replace slates over it.  I helped a roofer do it.
He just used a very long ladder.  On my own I would have fixed a rope.  But we walked across the slates in soft shoes.  The only problem is condensation running back through the extractor.  I can't think of a solution to that.

In reply to Si dH:

I did mine myself, bought one of these, reasonably easy to do.

https://www.roofingventilation.co.uk/Redland-51-Double-Roman-Roof-Tile-Cowl...

In reply to David Riley:

It should be insulated when running through an unheated loft space and a vertical flue needs and should have a condensate trap. You don’t want condensate running back through a fan if only from a safety point.

I had to get my flue insulated, and due to condensate my fan had started to corrode and it failed prematurely and had to be replaced.

It shouldn’t be underestimated how much water needs to get outside with heated saturated air being pushed along. I have my outlet “draining” down to a soffit board vent and in winter over just a couple of weeks I can get up to a 100 mm high ice “stalagmite” on a lintel below the vent. I’m going to get the fins of the vent changed to direct away from the house.

In reply to Climbing Pieman:

The fans are low voltage.  So no safety issue.

Insulation would probably have little effect on condensation.   It mostly occurs at the roof level which, exposed to wind, could not be kept warm.

Traps in the bathroom ceilings would seem to be the answer.  But would need piping to connect to the drains.   More work than everything else put together.

In reply to Si dH:

Weird choice from them to make a fuss over it only to vent it into the loft. I think I'd rather have the problems in the bathroom. I can a) notice and b) deal with mouldy silicone. The outcome of a damp roof space, less so.

In reply to Si dH:

Two wrongs don't make a right.  You'll only get the rain drips when it rains, but you'll get condensation from the steam all the time. They're just trying to justify the fact that they've done a shit job.  In terms of getting the pipe to outside, slate vents with mesh on them don't flow very well and are relatively prone to blocking with dust and cobwebs.  You need to match the cross-sectional area of your duct ideally.

In reply to Si dH:

You can get various plastic 4" round > shape adaptor pieces (screwfix/toolstation etc), I think mostly aimed at putting ducts in stud walls and under floors, might that give you a clean exit at the sofit? You don't want it venting into the attic, while it will mostly be fine in summer there will be plenty of days it does condense.

I have quite a long vent pipe run in the attic (vents out of a hole in the gable wall), making sure it drains condensate out rather than back into the fan was my main worry.

jk

In reply to Si dH:

Building regs I believe require mechanical ventilation for newly converted bathrooms.  However, in a non-newly-converted one, I find just opening the window wide when showering (even in winter) prevents any damp issues (and to act as a control, when I had a lodger he didn't used to open the window, and a damp and black mould issue started to develop).  So unless you're about to sell up I'm not sure I wouldn't just not bother and open the window when showering, unless that's inconvenient (e.g. because people could see in).

Most damp problems in bathrooms are caused by people not bothering to open windows where a fan isn't fitted (and to be honest many fan installations are inadequate anyway).

In reply to Si dH: I would get new electricians!

As others have said there are all types of adapters to fix permanently to the  soffit, and they are pretty cheap, so it sounds like your trades just couldn't be bothered. You could probably do it yourself if you don't mind getting a bit hands on.

There may be some ventilation to the loft, but I'd be concerned it is not enough, especially in winter when damp is more of a problem, and for whatever reason the ducting might move a bit.

In reply to Mike Stretford:

Thanks.

Just to defend the guys slightly (not sure why) it is a more tricky job than you might expect I think. There is no real soffitt of any size, the overhang of the roof out from the wall is very small and partially blocked by an extra row of decorative bricks that stick out from all the bricks below; the gap of 3cm width that I described above is the width of what essentially is the soffitt. There is nowhere that you could fit any sort of premade solution designed for a normal sized soffitt. The house was built 1880s so is far from what you would expect in something more modern. The loft is also a horrible environment to work in, there is little space near the edge (it's a stomach crawl) and the whole thing is full of old lime/horsehair debris that has fallen off the inside of the roof over many decades so it's very dusty. You can't work up there without a headtorch and a mask on the whole time.

I think either a slate vent solution, unusually small vent in the wall or opening the window are going to be the only options.

In reply to Si dH:

Fair enough, that sounds horrible, but they should still have given you the options for the final fix.

Is it a terrace with no outside wall either side?

BTW, my loft was nasty so I put this down this stuff over all the old shite

https://www.diy.com/departments/diall-insulation-roll-l-6m-w-0-37m-t-100mm/...

A bit pricey but insulates well, keeps the dust down, and isn't itchy.

In reply to Si dH:

On last thing, if you have loft insulation or add some it's good to provided some extra ventilation to the loft anyway, as a 'cool' loft can get damp. Old houses were designed to have drafts and coal fires going in several rooms and a warmer loft.

In reply to Si dH:

A ducted dehumidifier in the loft, and draining in to the bathroom waste is another option.  Probably not cheap, it will cost in electricity but it will save in central heating in winter.