Insane bathroom condensation

[MartyJ]

Renovated a bathroom 2 years ago, took it back to brick and started again basically. Did the research, rigid ducting being better than flexible etc, short runs as possible, extractor close to shower and so forth. Yet the condensation in the bathroom after a long shower (anything over 10 mins) is crazy, water literally pooling on the ceiling and every wall (fully tiled floor to ceiling) dripping. Have tried three different extractors to no avail.

In the past have never had a fully tiled wet room, always had tiling around shower only etc then normal plastered walls. Is this a function of it being a wet room ie normally does the plaster absorb some of the condensation and later dry out etc?

Picture below of the extractor ducting, would say there is about 1.4m in horizontal length to the outside vent

 

[Ivor Windybottom]

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[Ivor Windybottom]

What fan do you have? I have a "quiet" one and it's useless, I'm about to change it for a decent one. But some amount of condensation is fairly inevitable. Do you have lots of ceiling/wall insulation? Also get the room heated well before you shower, so that the surfaces aren't as cold.

 

[MartyJ]

What fan do you have? I have a "quiet" one and it's useless, I'm about to change it for a decent one. But some amount of condensation is fairly inevitable. Do you have lots of ceiling/wall insulation? Also get the room heated well before you shower, so that the surfaces aren't as cold.

Got the below, one of the highest L/m I could find that fits rigid pipe (unfortunately a few models have ridges on them that mean despite being advertised for 100mm they don't actually fit within). Walls and ceilings have 150mm PIR and the radiator is on 22c the whole time although the surface of the tiles never actually feel warm

Lo-Carbon Svara White | Vent-Axia

www.vent-axia.com

 

[Alastairreid]

Do you have a gap under the bathroom door?

 

[Murdochcat]

Do you have a gap under the bathroom door?

Minimum 6 mm and keep the windows closed too

How is the room heated?

 

[foxhole]

In-line fan is required if you are taking 10min showers ( you must be filthy?)

 

[^woody^]

Open the window.

Is the fan directly over the shower enclosure?

 

[MartyJ]

Right, could be onto something with the door gap, eye balling it looks to be 4-5mm on average. If 10mm is the minimum... What's the ideal? Guessing not much more as poor aesthetics would come into play.

Online fan is required if you are taking 10min showers ( you must be filthy?)

Teenagers.....

Open the window.

Is the fan directly over the shower enclosure?

Unfortunately the window opening is over the bath and fairly high ie I know it's unlikely my children will open it let alone close it. Fan is horizontally 30cm from the shower enclosure.

Room is heated by a tall column radiator

 

[Wayners]

Ceiling has insulation above? I don't get any condensation on my bathroom ceiling as its in the centre of the house with 200mm of insulation above.
No window because we extended out.
Just happens to be the walls that surround bathroom are warm so condensation doesn't get created.
Mirror gets wet though but that's gone in 15 mins.
You need to find away to insulate the surfaces to raise the dew point.

Also house maybe airtight so no air getting in as exstractor pushes air out

 

[MartyJ]

Ceiling has insulation above? I don't get any condensation on my bathroom ceiling as its in the centre of the house with 200mm of insulation above.
No window because we extended out.
Just happens to be the walls that surround bathroom are warm so condensation doesn't get created.
Mirror gets wet though but that's gone in 15 mins.
You need to find away to insulate the surfaces to raise the dew point.

Also house maybe airtight so no air getting in as exstractor pushes air out

3 of the 4 walls are internal walls ie aren't insulated whereas the one external wall and the ceiling have 150mm PIR. Extraction works fine up to the 10 mins mark, no obvious signs of condensation etc but when the kids go for their long dramatic showers it turns into a rainforest. All windows have trickle vents and extractor set to continuously on (and boost with light switch/humidity)

 

[Murdochcat]

So do NOT open the window, increase the gap under the floor AND extend the time the timer overrun boost runs for to at least 15 mins.

 

[MartyJ]

So do NOT open the window, increase the gap under the floor AND extend the time the timer overrun boost runs for to at least 15 mins.

This sounds like a good plan.

Thanks all for your help, very much appreciated

 

[GillObrien]

We have an internal bathroom with no window and, whilst the fan works relatively well despite being ancient (we have an in-line one with two ceiling ducts), we also do the following:

- clean water off all the shower walls with a squeegee after each shower.
- run a small table top dehumidifier during and for 15 minutes after the shower (we find this slows the build up of condensation).

We find that this makes a big difference. Even my ten year old is well trained in the art of the sqeegee now!

 

[MartyJ]

We have an internal bathroom with no window and, whilst the fan works relatively well despite being ancient (we have an in-line one with two ceiling ducts), we also do the following:

- clean water off all the shower walls with a squeegee after each shower.
- run a small table top dehumidifier during and for 15 minutes after the shower (we find this slows the build up of condensation).

We find that this makes a big difference. Even my ten year old is well trained in the art of the sqeegee now!

100% on the squeegee, if anything if you don't do it you're forever cleaning the streaks! We actually had a huge humidity issue when we moved in a couple of years ago, short version is that a breathable Edwardian property had been blocked up, so we installed trickle vents, constant forced ventilation as well as fixed blocked roof ventilation. Coupled with some large dehumidifiers we got the house humidity down from 75%-80% to 50% which is as good as I'll probably get it. The giveaway was the lovely mould in the loft from the condensation but was a positive in the long run as at that stage of the renovation got me thinking about things in terms of airflow etc