Preventing damp and condensation

Albermarle

GrubbyGirl_2 said:

Many many years ago when I lived in a house that was especially damp in the bathroom I found that using a squeegee (like you do the windows with) to go over all the tiles and shower screens and the shower tray itself to push as much water down the plughole as possible made a huge difference to the amount humidity in the bathroom after using it. we also made sure the toilet seat was always down.  The theory being to reduce the amount of water in the bathroom reduces the amount that can evaporate.  It improved things for us so might be worth a try

Or even smaller ones like you use on car windows.
Also you can buy nicer looking ones that you can keep in the bathroom, with a small wall fitting to hang it one ( or a magnetic fitting) .

ThisIsWeird

CurlySue2017 said:

(1) Ventilation is all well and good, but you don't want your windows open when it's this cold outside and personally, I find it doesn't actually help that much when the air outside is so cold!  There's actually condensation on the outside of the windows so that theory is, in my opinion, questionable.

My suggestions would be:
(2) Make sure the trickle vents on the windows are open and leave them open.
Use extractors wherever possible and leave them running after you have finished, so say ten or fifteen minutes after taking a shower, the same after cooking. 
I use a dehumidifier when drying washing indoors - left in the same room as the drying, door closed, run overnight (we are on Economy 7 so cheaper overnight).  The dehumidifier also kicks out a bit of heat itself, so that takes the edge off the cold.

There is some condensation of course, but a quick daily wipe of all windows with a squeegee gets rid of it and we don't get any mould.

Good advice.

For (1), I certainly wouldn't suggest having a window even on 'vent' setting if it's a room you are trying to heat and are actually using; as you say, this would be wasted heat (unless you can see condensation problems forming). However, once you leave that room and turn off the heating in it, you should crack open some element of ventilation. If you don't, then almost certainly the moisture that was held in that warmed air will condense out on the coldest surfaces - usually the windows - when the heating goes off and the temp drops - typically overnight. Next morn you'll have running windows.

Again in (2) - any room you are not using, and are not heating, make sure it's thoroughly ventilated, and closed off to the rest of the house. Ma wee boy (standing at 6'2", but hey) is away for a few months, so his bedroom rad is fully off, and a window is open to 'vent'. It's bludy cold in there, but completely dry. If I shut that window - as it was a couple of weeks ago - there is condensation on the window in the morning, even tho' the door is closed; enough moist air seeps in from the rest of the house to condense out in what is one of the coldest areas. Window on vent, problem solved.

There is no need to be uncomfortably cold. Just heat the room and keep it draught-free when it's being used, and ventilate it when not.

Even bedrooms. Nuts having the rads on in them except for a half-hour before bed, and a half-hour before getup (or however long it takes to get the room pleasant for you). For the rest of the time, rads off, and vents open. Doors shut. When you turn on the rad before bedtime, by all means close the vents for that duration too. Then vice-versa when you actually go to bed - rad off, windows on 'vent'. Wake up to a dry room.

For drying clothes, if you have the luxury of a spare room, then clothes horse, door closed, and windows as wide open as they go! That won't cost anything, except perhaps a small draught into the rest of the house, but you can reduce that quite easily. Your clothes might not/ likely won't! get completely dry, but they will 80+%. Finish off either by using a dehumidifier in there (folk say this works) in which case you shut the windows, or else bring the 'orse into the warm living area to finish off slowly near a rad. The small amount of remaining moisture given out shouldn't cause a problem - and don't forget to vent that room overnight anyway.

CurlySue2017

ThisIsWeird said:

CurlySue2017 said:

(1) Ventilation is all well and good, but you don't want your windows open when it's this cold outside and personally, I find it doesn't actually help that much when the air outside is so cold!  There's actually condensation on the outside of the windows so that theory is, in my opinion, questionable.

My suggestions would be:
(2) Make sure the trickle vents on the windows are open and leave them open.
Use extractors wherever possible and leave them running after you have finished, so say ten or fifteen minutes after taking a shower, the same after cooking. 
I use a dehumidifier when drying washing indoors - left in the same room as the drying, door closed, run overnight (we are on Economy 7 so cheaper overnight).  The dehumidifier also kicks out a bit of heat itself, so that takes the edge off the cold.

There is some condensation of course, but a quick daily wipe of all windows with a squeegee gets rid of it and we don't get any mould.

Good advice.

For (1), I certainly wouldn't suggest having a window even on 'vent' setting if it's a room you are trying to heat and are actually using; as you say, this would be wasted heat (unless you can see condensation problems forming). However, once you leave that room and turn off the heating in it, you should crack open some element of ventilation. If you don't, then almost certainly the moisture that was held in that warmed air will condense out on the coldest surfaces - usually the windows - when the heating goes off and the temp drops - typically overnight. Next morn you'll have running windows.

Again in (2) - any room you are not using, and are not heating, make sure it's thoroughly ventilated, and closed off to the rest of the house. Ma wee boy (standing at 6'2", but hey) is away for a few months, so his bedroom rad is fully off, and a window is open to 'vent'. It's bludy cold in there, but completely dry. If I shut that window - as it was a couple of weeks ago - there is condensation on the window in the morning, even tho' the door is closed; enough moist air seeps in from the rest of the house to condense out in what is one of the coldest areas. Window on vent, problem solved.

There is no need to be uncomfortably cold. Just heat the room and keep it draught-free when it's being used, and ventilate it when not.

Even bedrooms. Nuts having the rads on in them except for a half-hour before bed, and a half-hour before getup. For the rest of the time, rads off, and vents open. Doors shut. When you turn on the rad before bedtime, by all means close the vents too. Then vice-versa when you actually go to bed - rad off, windows on 'vent'. Wake up to a dry room.

For drying clothes, if you have the luxury of a spare room, then clothes horse, door closed, and windows as wide open as they go! That won't cost anything, except perhaps a small draught into the rest of the house, but you can reduce that quite easily. Your clothes might not get completely dry, but they will 80+%. Finish off either by using a dehumidifier in there (folk say this works) in which case you shut the windows, or else bring the 'orse into the warm living area to finish off slowly near a rad. The small amount of remaining moisture given out shouldn't cause a problem - and don't forget to vent that room overnight anyway.

Totally agree, there's lots of things that are very simple but make a big difference.  We use a combined thermometer and humidity monitor and when ventilating, you can clearly see the difference it makes - the temp can be so low, but the humidity is super low, meaning the room is cold but dry.

This may be controversial but I think a lot of problems to do with moisture indoors is simply down to inaction.  Taking a little time each day to manage things generally means that you can control moisture and therefore avoid any problems with damp and mould.  Some people just don't want to bother taking that time.
OP is obviously trying to be proactive looking for suggestions, but I suspect lots of people don't bother 

Swipe

In any unheated rooms I just run a dehumidifier for an hour overnight and that keeps any condensation at bay. Even at -4C right now, the window only has a tiny 1cm band of condensation at the bottom of the window.

ThisIsWeird

Swipe said:

In any unheated rooms I just run a dehumidifier for an hour overnight and that keeps any condensation at bay. Even at -4C right now, the window only has a tiny 1cm band of condensation at the bottom of the window.

Have you tried simply ventilating these rooms instead? 

I'll happily bet you a non-existent £iver that simply having the windows on 'vent' overnight will mean not even a 1cm band of condie in the morning.

If you haven't tried this, please do. If it doesn't work, then go back to the de-humid.

Albermarle

ThisIsWeird said:

CurlySue2017 said:

(1) Ventilation is all well and good, but you don't want your windows open when it's this cold outside and personally, I find it doesn't actually help that much when the air outside is so cold!  There's actually condensation on the outside of the windows so that theory is, in my opinion, questionable.

My suggestions would be:
(2) Make sure the trickle vents on the windows are open and leave them open.
Use extractors wherever possible and leave them running after you have finished, so say ten or fifteen minutes after taking a shower, the same after cooking. 
I use a dehumidifier when drying washing indoors - left in the same room as the drying, door closed, run overnight (we are on Economy 7 so cheaper overnight).  The dehumidifier also kicks out a bit of heat itself, so that takes the edge off the cold.

There is some condensation of course, but a quick daily wipe of all windows with a squeegee gets rid of it and we don't get any mould.

Good advice.

For (1), I certainly wouldn't suggest having a window even on 'vent' setting if it's a room you are trying to heat and are actually using; as you say, this would be wasted heat (unless you can see condensation problems forming). However, once you leave that room and turn off the heating in it, you should crack open some element of ventilation. If you don't, then almost certainly the moisture that was held in that warmed air will condense out on the coldest surfaces - usually the windows - when the heating goes off and the temp drops - typically overnight. Next morn you'll have running windows.

Again in (2) - any room you are not using, and are not heating, make sure it's thoroughly ventilated, and closed off to the rest of the house. Ma wee boy (standing at 6'2", but hey) is away for a few months, so his bedroom rad is fully off, and a window is open to 'vent'. It's bludy cold in there, but completely dry. If I shut that window - as it was a couple of weeks ago - there is condensation on the window in the morning, even tho' the door is closed; enough moist air seeps in from the rest of the house to condense out in what is one of the coldest areas. Window on vent, problem solved.

There is no need to be uncomfortably cold. Just heat the room and keep it draught-free when it's being used, and ventilate it when not.

Even bedrooms. Nuts having the rads on in them except for a half-hour before bed, and a half-hour before getup (or however long it takes to get the room pleasant for you). For the rest of the time, rads off, and vents open. Doors shut. When you turn on the rad before bedtime, by all means close the vents for that duration too. Then vice-versa when you actually go to bed - rad off, windows on 'vent'. Wake up to a dry room.

For drying clothes, if you have the luxury of a spare room, then clothes horse, door closed, and windows as wide open as they go! That won't cost anything, except perhaps a small draught into the rest of the house, but you can reduce that quite easily. Your clothes might not/ likely won't! get completely dry, but they will 80+%. Finish off either by using a dehumidifier in there (folk say this works) in which case you shut the windows, or else bring the 'orse into the warm living area to finish off slowly near a rad. The small amount of remaining moisture given out shouldn't cause a problem - and don't forget to vent that room overnight anyway.

I think it  depends quite a lot on the actual property. I have found living in an older house ( mainly high ceilings, floorboards ( as opposed to a solid floor)  one open fire, largish hallway and wide stairs all the way up to the loft) that whatever you do, even drying clothes on radiators, baths, showers etc we never have any significant condensation and no mould problems at all. Except in the smallest bathroom when the weather is freezing like now.
I presume despite double glazing and draughtproofing, there is still enough air circulating naturally to avoid humidity problems.

Effician

My approach to condensation & damp is different to most now as in i  start with the RH that i feel comfortable with, using a dew point calculator i can get the temp that i need to keep internal surfaces above in order to avoid condensation forming, for me that's 6c at 16c RH52% or 20c RH40% or anything in between.

I've tried in the past all the methods above ie leaving windows open in closed rooms , trickle vents, dehumidifiers, extra heating etc but it either ended in a colder house still with condensation or higher heating or dehumidifer running costs.

Long story short, blocked all trickle vents, keep windows closed 99% of the time in winter ( warm days excluded), sold the dehumidifier & bought some low energy stand fans that run 24/7, keep all doors open to every room including unused ones. It's an old Victorian terrace with plenty of solar gain so great for opening front lounge window now on days like today ( not above freezing yet) & expell the warm moistish air through the back bedrrom window NNE facing, 10 mins is enough to change most of the air in the house ( with the fans running ) without losing the core heat from any room.

A single log burner with direct air feed is all we have for heating but it's enough as the house has no discernible draughts & the solar gain means 6hrs of free heat on sunny winter days.

I guess it's not all about ventilation & keeping rooms freezing cold , circulation works best for us as this keeps all the susceptible surfaces above dew point for our chosen RH while keeping the whole house at a reasonable temp for minimal running costs.

outtatune

Whatever you do, don't combine ventilation with a dehumidifier! Or you'll be paying electric costs to pull damp air in from outside.

Right now I have a dehumidifier running as I'm at home and really don't want to be opening the windows or my bits will start freezing, and it's currently pulling about a litre every 5 hours out of the air.

ThisIsWeird

Albermarle said:

ThisIsWeird said:

CurlySue2017 said:

(1) Ventilation is all well and good, but you don't want your windows open when it's this cold outside and personally, I find it doesn't actually help that much when the air outside is so cold!  There's actually condensation on the outside of the windows so that theory is, in my opinion, questionable.

My suggestions would be:
(2) Make sure the trickle vents on the windows are open and leave them open.
Use extractors wherever possible and leave them running after you have finished, so say ten or fifteen minutes after taking a shower, the same after cooking. 
I use a dehumidifier when drying washing indoors - left in the same room as the drying, door closed, run overnight (we are on Economy 7 so cheaper overnight).  The dehumidifier also kicks out a bit of heat itself, so that takes the edge off the cold.

There is some condensation of course, but a quick daily wipe of all windows with a squeegee gets rid of it and we don't get any mould.

Good advice.

For (1), I certainly wouldn't suggest having a window even on 'vent' setting if it's a room you are trying to heat and are actually using; as you say, this would be wasted heat (unless you can see condensation problems forming). However, once you leave that room and turn off the heating in it, you should crack open some element of ventilation. If you don't, then almost certainly the moisture that was held in that warmed air will condense out on the coldest surfaces - usually the windows - when the heating goes off and the temp drops - typically overnight. Next morn you'll have running windows.

Again in (2) - any room you are not using, and are not heating, make sure it's thoroughly ventilated, and closed off to the rest of the house. Ma wee boy (standing at 6'2", but hey) is away for a few months, so his bedroom rad is fully off, and a window is open to 'vent'. It's bludy cold in there, but completely dry. If I shut that window - as it was a couple of weeks ago - there is condensation on the window in the morning, even tho' the door is closed; enough moist air seeps in from the rest of the house to condense out in what is one of the coldest areas. Window on vent, problem solved.

There is no need to be uncomfortably cold. Just heat the room and keep it draught-free when it's being used, and ventilate it when not.

Even bedrooms. Nuts having the rads on in them except for a half-hour before bed, and a half-hour before getup (or however long it takes to get the room pleasant for you). For the rest of the time, rads off, and vents open. Doors shut. When you turn on the rad before bedtime, by all means close the vents for that duration too. Then vice-versa when you actually go to bed - rad off, windows on 'vent'. Wake up to a dry room.

For drying clothes, if you have the luxury of a spare room, then clothes horse, door closed, and windows as wide open as they go! That won't cost anything, except perhaps a small draught into the rest of the house, but you can reduce that quite easily. Your clothes might not/ likely won't! get completely dry, but they will 80+%. Finish off either by using a dehumidifier in there (folk say this works) in which case you shut the windows, or else bring the 'orse into the warm living area to finish off slowly near a rad. The small amount of remaining moisture given out shouldn't cause a problem - and don't forget to vent that room overnight anyway.

I think it  depends quite a lot on the actual property. I have found living in an older house ( mainly high ceilings, floorboards ( as opposed to a solid floor)  one open fire, largish hallway and wide stairs all the way up to the loft) that whatever you do, even drying clothes on radiators, baths, showers etc we never have any significant condensation and no mould problems at all. Except in the smallest bathroom when the weather is freezing like now.
I presume despite double glazing and draughtproofing, there is still enough air circulating naturally to avoid humidity problems.

You are absolutely correct.

We have a '30s bungalow (now lofted), and we have zero condie issues in the front downstairs sitting room. Why? 'cos there's a fireplace (even tho' stove now added), and T&G floorboards throughout the whole downstairs. It's as draughty as my botty after a beanstew. Hardly ever do we find any condie on the windows, even with the clothes 'orse in the room, so that's the 'plus'.

BUT, the living area is a bar steward to heat! CH running overtime, and stove on too - the temp is creeeeping up to above thawing :-) It's TOO bludy ventilated.

Albermarle

ThisIsWeird said:

Albermarle said:

ThisIsWeird said:

CurlySue2017 said:

(1) Ventilation is all well and good, but you don't want your windows open when it's this cold outside and personally, I find it doesn't actually help that much when the air outside is so cold!  There's actually condensation on the outside of the windows so that theory is, in my opinion, questionable.

My suggestions would be:
(2) Make sure the trickle vents on the windows are open and leave them open.
Use extractors wherever possible and leave them running after you have finished, so say ten or fifteen minutes after taking a shower, the same after cooking. 
I use a dehumidifier when drying washing indoors - left in the same room as the drying, door closed, run overnight (we are on Economy 7 so cheaper overnight).  The dehumidifier also kicks out a bit of heat itself, so that takes the edge off the cold.

There is some condensation of course, but a quick daily wipe of all windows with a squeegee gets rid of it and we don't get any mould.

Good advice.

For (1), I certainly wouldn't suggest having a window even on 'vent' setting if it's a room you are trying to heat and are actually using; as you say, this would be wasted heat (unless you can see condensation problems forming). However, once you leave that room and turn off the heating in it, you should crack open some element of ventilation. If you don't, then almost certainly the moisture that was held in that warmed air will condense out on the coldest surfaces - usually the windows - when the heating goes off and the temp drops - typically overnight. Next morn you'll have running windows.

Again in (2) - any room you are not using, and are not heating, make sure it's thoroughly ventilated, and closed off to the rest of the house. Ma wee boy (standing at 6'2", but hey) is away for a few months, so his bedroom rad is fully off, and a window is open to 'vent'. It's bludy cold in there, but completely dry. If I shut that window - as it was a couple of weeks ago - there is condensation on the window in the morning, even tho' the door is closed; enough moist air seeps in from the rest of the house to condense out in what is one of the coldest areas. Window on vent, problem solved.

There is no need to be uncomfortably cold. Just heat the room and keep it draught-free when it's being used, and ventilate it when not.

Even bedrooms. Nuts having the rads on in them except for a half-hour before bed, and a half-hour before getup (or however long it takes to get the room pleasant for you). For the rest of the time, rads off, and vents open. Doors shut. When you turn on the rad before bedtime, by all means close the vents for that duration too. Then vice-versa when you actually go to bed - rad off, windows on 'vent'. Wake up to a dry room.

For drying clothes, if you have the luxury of a spare room, then clothes horse, door closed, and windows as wide open as they go! That won't cost anything, except perhaps a small draught into the rest of the house, but you can reduce that quite easily. Your clothes might not/ likely won't! get completely dry, but they will 80+%. Finish off either by using a dehumidifier in there (folk say this works) in which case you shut the windows, or else bring the 'orse into the warm living area to finish off slowly near a rad. The small amount of remaining moisture given out shouldn't cause a problem - and don't forget to vent that room overnight anyway.

I think it  depends quite a lot on the actual property. I have found living in an older house ( mainly high ceilings, floorboards ( as opposed to a solid floor)  one open fire, largish hallway and wide stairs all the way up to the loft) that whatever you do, even drying clothes on radiators, baths, showers etc we never have any significant condensation and no mould problems at all. Except in the smallest bathroom when the weather is freezing like now.
I presume despite double glazing and draughtproofing, there is still enough air circulating naturally to avoid humidity problems.

You are absolutely correct.

We have a '30s bungalow (now lofted), and we have zero condie issues in the front downstairs sitting room. Why? 'cos there's a fireplace (even tho' stove now added), and T&G floorboards throughout the whole downstairs. It's as draughty as my botty after a beanstew. Hardly ever do we find any condie on the windows, even with the clothes 'orse in the room, so that's the 'plus'.

BUT, the living area is a bar steward to heat! CH running overtime, and stove on too - the temp is creeeeping up to above thawing :-) It's TOO bludy ventilated.

It is trade off for sure. Good natural ventilation/ a bit draughty, means no condensation but higher heating bills.
In fact our house is not too bad to keep living areas warm as the rooms are not large, we have newish carpets, newish underlay and a liner underneath to stop the cold coming up through the floorboards. However it is necessary to keep warm rooms doors closed, or nearly closed, or all that heat is lost into the hallway and up the stairs. It is a point of domestic tension in the cold weather as not everybody is as good at remembering to close the doors as others....