Condensation in bathroom!

[Flyfisher]

so leaving the window open, which I have always done in previous properties, is an obvious waste of heat, and provides a good view for the neighbours!!!!

Well, that's certainly one way to introduce yourself to your new neighbours!

As for fan noise, my limited experience is that the smaller fans are the noisiest. They need to spin faster to move the same volume of air as a larger one and the faster they spin the noisier they are. Having said that, fans don't need to be switched on all the time and are not usually audible over a decent shower.

 

[MdB]

To hijack this thread with my own question...

Here is our delightful bathroom. It will look a lot better when finished (it better!)

A shower is going to be fitted at the end of the bath on the left. The left hand wall is attached to the rest of the house. The rear and right hand walls are outside walls (you can just see the corner of the window on the right). The roof is a flat roof.

The question is where to put the extractor fan?

Options are:
1) Rear wall in the top left corner close to the shower, but also close to your head when showering.
2) Rear wall in the top right corner. My favourite option.
3) In the ceiling. Would require long ducts and would be difficult to fit.
4) Right hand wall

Is there any good reasons to put it in any particular position or can I just put is anywhere really?

(I will get a zone 1 / zone 2 extractor fan so electrically there won't be a problem wherever it is put.

 

[Pford75]

Noise can be almost completely removed if you opt for an 'in-line' extractor fan.

We have a small grille fitted into the ceiling, which is then connected to a tube running through the loft. The fan is 'in-line' in the loft above the insulation and is almost completely silent.

As MdB says, it just requires a bit of thought in how you do it.

 

[Pford75]

I would also suggest having a look at this range of 'discreet' fans

http://www.epicair.co.uk/bathroom-extractor-fans-discreet-bathroom-fans-c-43_25.html

 

[AMc]

Noise can be almost completely removed if you opt for an 'in-line' extractor fan.

Agreed, as an interim measure to refitting and reorganising the modern bathrooms in my house I disconnected the noisy ceiling mounted fan in one and cut an inline one in the roof void above it. It's quieter and more efficient than the old one.
Not all fans are created equally even at the same size and power/extract rate - check the dB rating and go for the lowest number you can find.

MdB - If I were you I would fit the vent above the shower (moving the moisture out as close to source as possible) and use an inline fan mounted above the ceiling. When the shower is on you won't notice the draught. If you're looking at changing the lighting then the recessed vents with lights built in are worth a look.

 

[MdB]

AMc - Thanks. The ceiling option with an inline fan would be great apart from actually fitting it. I can get the duct into the main loft area easily enough but there then isn't an easy option to the outside from there. I will have another look at this option though to see if I can come up with some clever way of fitting it.

 

[Penners]

As Lime and Flyfisher have pointed out, stripping off the paint and replacing plastic in the room isn't really going to be the answer to condensation. Ventilation is what's needed. And an effective extractor fan is going to be more effective for this than opening the winow (in winter, anyway).

The fan will draw most of its supply of air into the bathroom around the door (indeed, it's worth having a bit of a gap under the door for this purpose). So it will be warm(ish!) air from the interior of the house. Warm air can carry more moisture vapour than cold air, so the extractor will be removing a fair bit of the moisture that is causing your condensation.

The usual specification for a typical bathroom extractor fan is a capacity of 15 litres/second, but you might do well to increase that a fair bit. You might also consider having the fan controlled by a humidistat on the bathroom wall, rather than just the usual light switch and run-on timer. This would ensure that the fan kept runnign until the humidity of the bathroom air had been reduced to your chosen level.

As others have said, a fan creates a bit of noise, but it's not a big deal. And as Pford75 and AMc said, an inline fan located somewhere in the loft can be pretty quiet.

In summer, of course, Lime's preferred fresh air solution will be effective and pleasing.

 

[worms]

Interesting topic this and with a nod to the "any Real experts here" thread, I would want it noted that I have no expertise in this whatsoever! However...

I accept the airflow and extractor fan argument - that almost goes without saying. But surely there is an issue over having a surface on the walls that is porous and can absorb and release moisture rather than a waterproof surface which leads to a film of condensation which will support the growth of mould? In these circumstances, will a traditional plaster finish and a limewash or distemper paint not manage the surface moisture much better, as long as the humidity levels don't remain so high that all you do is keep loading moisture into the wall (which would presumably lead to eventual failure of the plaster or other problems)?

 

[MdB]

<vague memory mode on>
Didn't somebody say in the past that some European bathrooms are covered in unglazed ceramic tiles so as to be able to absorb condensation and then release it slowly? Probably have that completely wrong. (He says currently putting glazed tiles onto the wall in the bathroom)

 

[Lime]

Interesting topic this and with a nod to the "any Real experts here" thread, I would want it noted that I have no expertise in this whatsoever! However...
I accept the airflow and extractor fan argument - that almost goes without saying. But surely there is an issue over having a surface on the walls that is porous and can absorb and release moisture rather than a waterproof surface which leads to a film of condensation which will support the growth of mould? In these circumstances, will a traditional plaster finish and a limewash or distemper paint not manage the surface moisture much better, as long as the humidity levels don't remain so high that all you do is keep loading moisture into the wall (which would presumably lead to eventual failure of the plaster or other problems)?

Yes, I think the type of wall and it's covering very important with relation to condensation.
A cement skimmed brick wall with hard glazed tiles is far more likely to have condensation upon it than a simple lime plastered wall for instance, at least IME.

 

[Flyfisher]

I can see a physical difference between condensation 'sitting' on top of impermeable walls and condensation soaking into permeable walls, but isn't the overall effect of 'water somewhere' going to lead to the same potential mould problems in either case? Indeed, wouldn't it be easier to clean away any mould from a glossy, impermeable surface than a permeable one? Also, would a permeable surface only help to average out the higher water content, which might actually help mould growth compared with a glossy surface that cycles between very wet and very dry?

I still think it's best to get as much water vapour as possible out of the room before it has a chance to condense anywhere inside, implying windows and/or fans.

 

[Lime]

I still think it's best to get as much water vapour as possible out of the room before it has a chance to condense anywhere inside, implying windows and/or fans.

Absolutely right but I think there is some difference in walls with regard to their thermal conductivity, i.e. does the wall feel cold to the touch and does it warm up quickly.
A wall that "stoically" remains cold WILL have condensation upon it eventually while a wall that warms up quickly is far less likely to.

 

[Flyfisher]

Agreed. This water vapour/condensation issue is a curious thing. Warm surfaces will certainly cause less condensation than colder ones and keeping the bathroom nice and warm might cure the local problem but what happens when the door is opened after a shower? All that humid air will move into the cooler areas of the house and condense somewhere else - probably in cool areas behind behind wardrobes and other furniture. OK, so keep the house nice and hot to prevent condensation anywhere and (quite apart from the cost and energy implications) it ends up as a tropical rainforest! Ventilation is the only answer.

My other ventilation hobby horse concerns those TV adverts for 'air fresheners'. Apparently one can now buy plug-in devices that emit a constant stream of 'freshening' scent (aka chemicals) as well as the usual aerosols and candles to do the same job, all of which are presumably designed to cover up the increasingly 'stuffy' atmosphere in modern draught-proof homes. I'm a naturally relaxed soul but when assailed by an advert asking 'Nasty Smells?" I find myself shouting "well open the bl**dy window then!!!" at the TV screen.

 

[Lime]

keeping the bathroom nice and warm might cure the local problem but what happens when the door is opened after a shower? All that humid air will move into the cooler areas of the house and condense somewhere else

I keep both bathrooms quite warm, the doors are normally open when vacant warming the upstairs.
All the fabric and interior of the rooms are warm so my opening the windows for my "blow out" of damp (a previous post) doesn't cause much discomfort whatever.
However perhaps you have hit on the major cause of condensation, a cold bathroom, hot steamy showers and inadequate ventilation.

On other point you make, re air fresheners, I couldn't agree with you more.
The whole idea that as a cure for a house that has a stink in it the solution is to spray another overpowering stink on top of it makes my stomach heave.
Modern houses must stink a lot too as these sprays are very expensive but appear to sell like hot cakes.

 

[Penners]

I ought to follow worms' protocol and deny any and all accusations of expertise. The following is nothing more than an amateur gut feeling.

I'm in Flyfisher's camp. While I don't deny that an absorbent wall will tend to show less condensation than, say, a glazed tile wall, I'm not sure that it's much of a solution to the problem. After all, the moisture is still there, albeit 'stored' in the wall. At some point it'll still have to come out and be carried away somehow.

If you can substantially increase the insulation of the external wall(s) of the bathroom, then of course they will tend to precipitate less condensation, because they will be warmer. But no matter what you do, a shower will still create pretty much the same amount of steam. And that moisture has to be got rid of, if you don't want a damp and potentially mouldy room.

Lime is quite correct that it could be wafted around the house and out of open windows. But do you want to keep opening your windows in winter? If not, then I return to my earlier suggestion of a humidistat-controlled extractor fan.

By all means create some porosity in your walls, but even if this shows a sight reduction in your condensation, the moisture is still there!

 

[jocelyn plummer]

Yes, I agree with Penners , the moisture is still there, no matter what you do! Anyway,after all the long discussions and good advice , and as I find it un-nerving to see oily drips running down the wall I am going to steam ahead and clean off the vinyl paint, get rid of the plastic tongue and groove, bathe with the window full open for all to see, keep the cast iron rad on all the time; with only one outside wall to worry about -- fingers crossed--moisture out of sight out of mind!

Having now been here for 6 weeks we've just realised that there are no door handles on many of the doors--- gone! It just goes to show what a bit of clever presentation for sale can do to even the most discerning eye! The doors have all been dipped so they are very wonky. It is quite strange having to put right 'minor' and rather mundane things instead of major restoration.

 

[Lime]

It is quite strange having to put right 'minor' and rather mundane things instead of major restoration.

Said before removing plastic etc.
Brave person!

 

[Pford75]

Are you sure the vendors didn't just take the handles with them?

Our vendors took all of the lightbulbs, dug up plants from the garden and removed all the curtain poles rather roughly, leaving great big holes in the walls

 

[Lime]

Are you sure the vendors didn't just take the handles with them?

Our vendors took all of the lightbulbs, dug up plants from the garden and removed all the curtain poles rather roughly, leaving great big holes in the walls

Huh!
You're lucky!
Ours took the Edwardian letter box, knocker and the stained glass from out of the front door which I found difficult to believe.
(And, yes, they did mention it in the small print tucked away right at the bottom of a bunch of pages given us so could do nothing about it.)
They left us a cupboard full of cut glass vases and several piles of beatles magazines from the 60s though.

 

[Moo]

We were set an excellent example by the previous owners of our lovely house-before-last.
They left us: loo paper in every loo; soap on every basin; lightbulbs in every socket; and a list of recommended local shops and tradesmen.
When we moved we did the same for the new owners.