Have I created a condensation problem?

[kenam]

I,

Just got bathroom done and a central heating system installed (by separate people).

The bathroom is tiled fully to the ceiling, he ceiling has been plastered but not as yet decorated.
The central heating was done before hand and we opted for a small towel rail inside the bathroom. Before the central heating was done, we got an extractor fan fitted as well.

I thought with heating on and the fan running, the bathroom would be fine. But it is normally still quite cold in there (I think having an extractor fan - basically a hole in the wall - and tiled walls is not helping).

Each time we take a shower, all tiled walls are dripping. Now with he extractor on and a window open, it does eventually clear (but takes up to an hour).


Have I inadvertently created a future condensation problem? Or should I go an invest in a bigger rad/ towel rail now?

Also - should I do anything special with the bare plaster on the ceiling?

 

[ajstoneservices]

Get that bare plaster painted asap or the condensation will ruin it.

 

[kenam]

Get that bare plaster painted asap or the condensation will ruin it.

Will do - might be another week or so tho..
Is it ok to do the same as I done with the other plastered (non bathroom walls) - I was using white emulation with no vinyl in it - but maybe for a bathroom finish coat I should use a heavier paint?

 

[Gerrydelasel]

Use bathroom paint.
Bathroom walls are very often dripping after a shower or hot bath, it's a fact of life! Bathrooms are only perfect, dry, mould-free utopias in style magazines. In real life they're something you have to learn to manage according to your particular room's quirks. You should keep your showers as short as possible, crack the window and squeegee the walls when finished -your mum should have taught you from an early age. Leaving the door open helps too, unless you have visitors Your bathroom will teach you how it wants to be used, not the other way around.
FYI, towel rails are not normally substitutes for proper radiators, unless it's a special model or a very small room. But making the room warmer may not help with condensation much, it will just localise it more.

 

[big-all]

you need a 12mm gap under the door to draw warm air from the rest off the house otherwise the fan will be fairly useless
opening the window will not help
try with the bathroom window shut and the door cracked open about 6mm

 

[Lower]

You need a bigger radiator and a better extractor.

You've got a condensation problem because the tiled walls are cold and there is lots of water vapour in there. If the extractor fan was better you'd get rid of more of the water vapour before it condenses and if the walls and ceiling were warmer then there would be less condensation in the first place.

However, you are always going to get some condensation in a bathroom. But if the room were warmer and the extractor fan better you'd find that the condensation you do get will clear more quickly too.

 

[foxhole]

Fan is under sized and/or in a poor position, more heat will not help as hot air holds more moisture than cold, you just need to move the air quicker, I have a fully tiled shower room and fan directly over shower, do not get any condensation on tiled surface.

 

[Lower]

More heat does help. If the air temperature is higher the air will hold the moisture for longer, giving the extractor fan more time to exhaust it. If the walls are warmer, less condensation will form on them.

Fan is under sized and/or in a poor position, more heat will not help as hot air holds more moisture than cold, you just need to move the air quicker, I have a fully tiled shower room and fan directly over shower, do not get any condensation on tiled surface.

 

[^woody^]

More heat wont help in a bathroom, where the issue is a lot of moisture produced in a short period of time and in a small space. Warm air wont have the time to hold the moisture and in any case, will be saturated within minutes.

You need extraction.

Now this can be via a window, but some moist air will tend to get into the other rooms as no-one, even with the best intentions, keeps the bathroom door closed until all the moist air goes out the window.

So fit a fan. But not just any old fan, fit a constant trickle fan with boost mode. www.vectaire.co.uk/products/el1003

 

[foxhole]

Agree Woody.

 

[Lower]

More heat wont help in a bathroom, where the issue is a lot of moisture produced in a short period of time and in a small space. Warm air wont have the time to hold the moisture and in any case, will be saturated within minutes.

You need extraction.

Now this can be via a window, but some moist air will tend to get into the other rooms as no-one, even with the best intentions, keeps the bathroom door closed until all the moist air goes out the window.

So fit a fan. But not just any old fan, fit a constant trickle fan with boost mode. www.vectaire.co.uk/products/el1003

My experience differs. I agree 100% with ventilation, but in my bathroom we had a very similar problem to the OP. We refurbished the bathroom which gave a much greater tiled area and painted the remaining plaster with bathroom paint as opposed to the matt emulsion that was there before.

It gave us a significant condensation problem. I upgraded the extraction fan which helped significantly, but the amount of condensation that actually forms on the walls is proportionate to how warm the bathroom is. We may get exactly the same amount of condensation forming irrelevant of temperature, but if the room is warm the walls and tiles dry much faster so the condensation appears to clear much more quickly.

 

[^woody^]

but the amount of condensation that actually forms on the walls is proportionate to how warm the bathroom

If the tiles are colder than the vapour in the air, then they will get condensation.

 

[chappers]

more heat will help, but only if combined with better ventilation. If you can heat the fabric of the room then the condensation can't form, however as Woody points out showering an bathing causes the air to saturate quickly.
But then if the air is warm it has the ability to then carry the moisture away much better than cold air.
Put your clothes in the tumble drier on cold or on hot and see which dries your clothes quicker or watch a puddle evaporate on a hot day compared to a cold day.

 

[endecotp]

we got an extractor fan fitted as well.

Does it go straight through the wall, or is there a long duct to the outside?

With the bathroom door closed and the fan running, is there enough suction that you can feel a draught under the door? If you offer up a piece of tissue to the fan will it hold it? What about a piece of a4 paper?

Where are the fan, shower and door in relation to each other?

 

[kenam]

Thanks for the replies.

I understand how the condensation forms and the relationship between heat and humidity, however I need to figure our the best way to solve this (or even if it is a problem!)

It seems I have 2 issues with he heat -

1. The extractor fan I have had fitted seems to be ok-ish when operation - I will look at adding a more powerful unit. However, the presence of the fan (and the duct) I think is a major contribution to the coldness - therefore any good it is doing by being on after a shower is somewhat negated byt the bathroom being a cpl of deg cooler to begin with!
2. The towel rail should prob be bigger and/or a rad

I guess it will come down to measuring humidity and the effect of leaving doors open / closed etc and a bit of:

Your bathroom will teach you how it wants to be used, not the other way around.