Condensation on the Cistern

[budwiser]

In our bathroom we have a problem with condensation forming both on the outside of the cistern (up to the water level) and on the cistern inlet pipe. This is obviously a significant problem in colder weather. Is there any way of resolving this issue as the condensation drips, forms pools on the floor and will ultimately damage the flooring.Any suggestions? All cures welcome.

 

[Johndug]

Open some windows to let the condensation away - or fit an extractor.

 

[budwiser]

Thanks. An extractor fan is fitted and operates when the lights are switched on. Also,we do try to keep the top quarter of the double-glazed window open by a small amount to allow ventilation.

 

[MarkJayne]

The only solution will be to get some heat into the room.
I take it that its not a plastic cistern or pipe.

 

[budwiser]

Thanks for the suggestion. The room is heated with a radiator, and even without the central heating on, it is not a particularly cold room, with three of the four walls being internal. The cold water supply however is particularly cold, if that's significant.
The cistern is porcelain, and the pipe's 15mm copper

 

[breezer]

only a thought.

perhaps its too warm in their, the hot air / moisture condensing on the cistern

 

[budwiser]

I know, I'm fairly puzzled by it all. I was hoping that someone had also experienced the same issues and had got a cure for it.
I wouldn't say that the temperature is too warm though, it's quite a comfortable temperature. However, at least one hot bath per day is run, with the subsequent increase in humidity.

 

[masona]

See this

 

[ChrisR]

Have watched over the last couple of years since the question arose. In warm, ventilated rooms it evaporates. Loos are often not warm enough. Really overheated bathrooms don't seem to have the problem. Worse on exposed pipes, which you just have to insulate.

 

[budwiser]

Thank you all for your comments and feedback. It was useful to read through. I think we will be trying to look at some means of heating the inlet water before it reaches the cistern. The water feed is currently directly off the rising main and we have no tank or capacity for a tank fed system to allow for the water to acclimatize before flushing. When the weather is cold outside the water is also colder. So the problem is greater. Also, when the frquency of flushes are high, the problem is also worse as a continual flow of new cold water arrives in the cistern. The idea of insulating the interior of the tank may be worth pursuing too.
In addition to this, I'm going to re-look at the extractor fan and put in a humidity stat.
If all fails, I'll move to The Tropics where humidity should be a little bit more manageable.
Until next time - THANK YOU

 

[ChrisR]

My experience of humidity stat (total ONE) is that it's really reliable. It comes on whenever its raining.

Let us know how the insulating goes - there is that thin polystyrene which is intended to go under wallpaper-?

 

[mildmanneredjanitor]

Would it help replacing the exposed section of copper pipe to plastic pipe? As this would partially insulate the cold water from the air?

I suppose (if you were doing any major work in the future) run the supply pipe next to a central heating pipe to allow the water to be warmed?

 

[DforDave]

Saw this on a "DIY Tips" site a while ago. Not convinced about it myself but would be interested to know if it works (and what it looks like).

Stopping condensation forming on a toilet cistern: This can be stopped by painting a coat of clear varnish on the cistern. This has better insulating properties than the glaze on the cistern and so stops the hot air condensing on the cold surface.

I have also heard of painting the inside of the cistern with something that forms a barrier, but as I can't remember what the product was called that's not much help either is it.

 

[mildmanneredjanitor]

Yes, I suppose you could paint the inside of a cistern with a bitumen type paint. That may help....

 

[DforDave]

I thought I would take this a step further and asked a product supplier if he knew of something suitable. Here is the relevant part of his reply..

I have been in the business 40+ years .... the problem you describe is certainly well known.

Do not waste you money on coatings, they will not do what you require. They are not thick enough to act as an insulant (which is what you require). They will simply adopt the same temperature as the ceramic or plastic cistern after a few minutes and your condensation will be back.

In real terms you need a 'Fully Bonded' layer of foam or polystyrene up against the cistern externally or internally, or actually lag it in a nicely hand made decorated plywood box type construction. into which you have bonded polystyrene ceiling tiles or the like, you could even put fibreglass loft insulation in it - just a thought.

If you want to be a real smarty, during the winter months drop into the cistern a small fish tank heater and thermostat, this will have the effect of not only raising the temperature of the residual water but also the ceramic cistern material too. As the toilet is not in continuous use it could stop the condensation forming on the outside.