Bathroom condensation

Elegran congratulations on your excellent scientific explanation. ?‍?

I might turn down the thermostat. Thank you for the ideas. Other people have jo Malone candles and fragrant eau de toilette in their bathrooms. I have strategically placed mould spray.

Turning down the thermostat on your hot water system might help, too!

Stansgran Sounds like you are fighting a losing battle. If you have tried the suggests from other contributors to this thread. I have found the best thing to get rid of black mould. After removing it with with salt with a bit of white vinegar using a toothbrush. A daily wipe with an antibacterial wipes kept it at bay. Hope that helps.

Stansgran* Can you install of those windows that can be opened and closed by pulling on a string? or retrofit some way of doing the same to the current window? He might find that "gadgety" enough to feel he was being with-it when he opened it. Stubborn little boys like gadgets.

Phoenix I just wish I had put the stars in the right place so that "warm air rises -* scientific fact* " had been shown in black properly.

Stansgran - better laminate it well, or the paper will sag with the condensation!

Something tells me he is about to be thoroughly passive-aggressed.

Probably a very hot bath is also not very good for him, can he not be persuaded to have it a bit cooler??

*Elegran I think you deserve the "Scientists White Coat Award" for your response!

That response (plus perhaps mine?) should fix the bu**er!

Stansgran if you can't beat him with science, beat him with a loofah, preferably on his behind!

When I was a child we had our first fitted bathroom with hot water from a Sadia . The plumber told us to always put cold water in the basin first so that the sudden heat from the hot water didn't crack the basin.

More importantly, putting cold water in the bath first and then adding hot up to the required temperature makes sure that you don't accidentally get into a scalding hot bath and end up seriously injured. Would this persuade him?

Don't mean to drip feed but we have a 50s post war house built by Jerry and the only bathroom is in the centre of the house with one small window which is best opened by an American baseball player - think Harlem Globetrotters. I need steps. When open it catches the wind as we live on top of a hill and there fore leads to rattling doors and rumblings and shakings in the night. Not making excuses but the bathroom with extractor fan is dry as you could wish when the cold water instead rule is followed( by me)
Elegran I do not nag! and thank you for your explanation which even I understand I will print that out and laminate it and hang it over the taps. I may not nag but I'm a dab hand at passive aggressive

I have been thinking about this, and how to put it to him so that he accepts that it is a scientific answer and not just a mere wife repeating old wives tales.

When hot water is run it produces water vapour, which rises to mingle with the dryer air already in the room. Air can only hold so much water vapour before it get over-saturated - and cold air can hold less than warm air - scientific fact. When the warm wet air comes in contact with a cold surface, it drops some of the water vapour as drops of water (probably with a sigh of relief as it does so.)

Very hot water run into a shallow container, like a bath, lands with a splash, sending lots of steam and water vapour up into the air. That hot water spreads out over the base of the bath, with plenty of surface area to mingle more water vapour with the air. It rises (because it is warm and warm air rises -* scientific fact*) and reaches the window. It can't rise right up and out because the window is closed, but the glass is nice and cold, so it condenses out and runs down in streams. If the window had been open most of it would have gone up and out

If you run cold water first (even a shallow layer of one inch or so) the very hot water falls into cold water, not onto a shiny bath surface so it 1) doesn't splash up so much and mix water vapour so readily with the dry air and 2) is cooled a little by mixing into the cold water, so it doesn't produce as much water vapour

And if you both open a window while you fill the bath and add a layer of cold before the hot, you achieve both of these improvements (and you wife stops nagging you about the waterfalls in the bathroom)

If you also open a window after your bath, too, the warm damp air remaining in the bathroom has a way to escape out of the window before the air cools down so far that it is no longer able to support any water vapour at all and drops it as condensation onto the cooling walls, floor, basin, toilet seat, doorhandle, loo roll . . . . .

I understood that condensation is hot moist air hitting a cold surface and a powerful enough extractor, for the size of the room, above the bath/shower will prevent most of it. Leaving the window open for an hour afterwards will also help solve the problem.

In this "official" leaflet, it says, "When filling the bath, run the cold water first then add the hot – it will reduce the steam which leads to condensation by up to 90%.", but it doesn't explain how it does it.
ciga.co.uk/wp-content/uploads/2017/09/CIGA_Condensation_Leaflet_WEB.pdf

So does this one - www.lbbd.gov.uk/sites/default/files/attachments/A-guide-to-condensation.pdf

In fact, ever other guide to condensation control I found in a Google search advises running cold water before hot water, so it is a generally known fact that this minimises condensation (though not apparently to your husband) Set your computer to do a Google search then bombard him with quotes.
They are not so good at explaining the exact mechanism which achieves that, but there must be an account somewhere.
Perhaps you could persuade him at least to open the window while the water is running, close it to have his bath (don't want him to freeze to death in this heatwave . . ) and then open it again once he is safely dry and dressed. Or would that be too much of a faff for him, and mean he would have to admit that you might be right?

An open window or a damn good extractor. Also one of those de-humidifying machines to suck out damp.

All for the sake of leaving the window ajar.

Thanks ladies but I need to blind him with science.

Get him to clean the bathroom

Opening the window is the answer, I don’t have an extractor but the window is open when I have my shower sometimes twice a day in Summer. I have no bathroom mould.
Even if he only opens it a crack whilst bathing but then once he’s done it needs to be open till the room dries out, I only close my bathroom window completely if I’m out or in the depths of Winter.