Internal humidity

Mary108

Hi all

I have those temperature/humidity guages (from amazon) dotted around my home and in the last few weeks I've noticed that the humidity is showing as 75 - 80% downstairs and around 67% upstairs (upstairs is always much warmer than downstairs). I understand that the humidity should be 30% to 60 % and mine was usually arounf 55-60% in the recent past

I can't see any signs of damp or mould on the walls or in the wardrobes although I do get some condensation on the windows when the temperature outside is cold, but not otherwise

Its a 1990s built detached house. Usual brick build

I don't have the heating on much but I try to keep the room temperature downstairs at around 15 C or above

Its rarely less than 17C upstairs

I try to balance the need to feel warm with my gas and electric bills not being too high!

I bought some of those dehumidifier pots and I've dotted them around the house but after a few days there's no water in the bottom half of any of them

I cant understand why these high humidity readings are showing all of a sudden when, so far at least, it doesnt appear that there is any dampness on the walls nor any mould

Can anyone advise what I should be looking at....might I have a leak somewhere which I cant see? A damp course issue?

How would I know?

Thanks in advance

Grenage

Outside humidity is about 90 now at 12 degrees.  You would need 17 degrees indoors too bring it down to 67% (before you consider added moisture).  20 degrees gets you to 54.

I'm not aware of passive dehumidifiers being at all effective.  You need to increase heat or use a proper dehumidifier to bring it down 

Mary108

Thanks for your reply Grenage. Much appreciated. The thing I can't get my head around is that high internal humidity has never happened before and in 2022 and 2023 I was also being super careful with how much I heated my home.

If high internal humidity had happened in 2022 and 2023, I would be expecting it this year too....does that make sense? 

I'm very concerned that there might be some dread leak or damp issue which I simply dont know how to find

leonard_455

If the weather's been a bit different this year—like more rain or humidity in the air—that could definitely play a role in what you're seeing inside your home. It’s kind of weird how these things can shift without any clear reason, right?

As for the potential leak, I get why that thought would be on your mind. Maybe start with a simple check around the house—like under sinks or behind appliances—to see if you can spot any moisture or even just a strange smell. It’s one of those things that can be hard to pinpoint, but sometimes just being a bit more vigilant can help

Grenage

Mary108 said:

Thanks for your reply Grenage. Much appreciated. The thing I can't get my head around is that high internal humidity has never happened before and in 2022 and 2023 I was also being super careful with how much I heated my home.

If high internal humidity had happened in 2022 and 2023, I would be expecting it this year too....does that make sense? 

I'm very concerned that there might be some dread leak or damp issue which I simply dont know how to find

It's relatively warm and humid outside.  Your readings are to be expected. 

You will likely find humidity drops with the outside temperature.

Mary108

Thanks @leonard_455

That's a good idea. I've asked a friend to pop over next week and check out my loft as I can get up there. 🙄 

Fingers crossed its as simple as the outside weather being more wet 

ThisIsWeird

Hi Mary.
Always sensible to have someone check out your loft for peace of mind, but almost certainly there is nothing unusual going on here. You don't seem to have an actual problem at all; the humid swings are normal, and aren't causing any issues.
Which rooms are downstairs, and which up? Where do you spend most time? Are there any rooms that you do not use at all, or rarely? And, which rooms have condensation on the windows at times?

[Deleted User]

Thank you for asking this question and for the helpful replies.  It's  really interesting and I have wondered about this since, with the loss of The £200 Winter Fuel Payment (at such short notice) I'll only be heating one room for a maximum of about 4 or 5 hours a day this winter.

I'm anxious to avoid mould and I appreciate these replies and Mary108's post, thank you.

leonard_455

Mary108 said:

Thanks @leonard_455

That's a good idea. I've asked a friend to pop over next week and check out my loft as I can get up there. 🙄 

Fingers crossed its as simple as the outside weather being more wet 

Glad I could help, let's just hope your friend will come as fast as posible

Mary108

Thanks @[Deleted User]. Trying to balance the monthly gas and electric costs and avoid humidity is turning into a bit of  anightmare this year.

@ThisIsWeird I tend to spend most of my time upstairs. I have a little office/sitting room which I use a lot. The temperature upstairs is usually around 19 C and the humidity is about 67% which is much higher than it has been in the last couple of autumns

Downstairs there is a large sitting room which I have tried to heat to about 15 - 17 C. The humidity in this room has shot up and earlier this  morning was 78%   I've cranked up the heating and its 19C in the sitting room now and 72% humidity, but of course, as soon as the heating goes off and the room cools....the humidity rises again!

I dont measure the temperature or humidity in the kitchen/utility/conservatory/cloakroom/bathrooms

The hallway which isnt heated at all is 16C at the moment with a humdity of 71%

Thanks for everyone's help and advice. I really appreciate it.

teaselMay

For reassurance put one of the meters outside (when it's not raining) for half an hour. It's very humid at the moment, in the 90s most days here, condensation on the outside of the windows some nights.

My heating hasn't been on yet and the humidity in the living room varies from low 50s to low 80s. No damp and no mould.

Plenty of ventilation windows open front and back of house for some of each day