How humid is your house?

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98elise

Original Poster:

28,183 posts

168 months

Saturday 19th October
quotequote all
In the past couple of years we've had a problem with damp/mould etc in winter. We get condensation on the windows, and you can feel it in the air. Humidity is never less than 65%.

Earlier in the year we discovered (and replaced) a leaking pipe under the kitchen floor, so was expecting things to be better as winter approaches.

Unfortunately nothing has changed, and were back to condensation on the windows. RH has been in the 70's in the past week and we're already getting mould. We vent the house as much as we can, anything over 16 I open the windows. We avoid drying clothes on radiators. We have extractors in the kitchen and bathrooms.

My mothers house is around 55% and she dries clothes on rack in the house, and her bathroom doesn’t have an extractor.

We've just bought a Meaco dehumidifier and it's been running all night taking about 2 litres of water out of the air. RH is still 67% (down from 72% last night). We have no condensation though, and the air is noticeably less humid.

What sort of humidity are you getting this time of year?


RoadToad84

767 posts

41 months

Saturday 19th October
quotequote all
60% is about where mine sits left to its own devices. I run a dehumidifier overnight in the bedroom and when drying laundry inside.

There's a good thread on here about positive internal ventilation systems (nuaire drimaster I think) which goes into quite a lot of detail on just this issue

craig1912

3,694 posts

119 months

Saturday 19th October
quotequote all
RoadToad84 said:
There's a good thread on here about positive internal ventilation systems (nuaire drimaster I think) which goes into quite a lot of detail on just this issue
Yep that will in all probability solve the issue and then no need for a dehumidifier

98elise

Original Poster:

28,183 posts

168 months

Saturday 19th October
quotequote all
craig1912 said:
RoadToad84 said:
There's a good thread on here about positive internal ventilation systems (nuaire drimaster I think) which goes into quite a lot of detail on just this issue
Yep that will in all probability solve the issue and then no need for a dehumidifier
I'll probably look at that as a long term solution.

What I can't fathom is why it's started in the past few years. I was convinced the leaking pipe was the culprit. We had a constant flow of water under the floor.

megaphone

10,933 posts

258 months

Saturday 19th October
quotequote all
When was the house built? I find 'new builds' have more issues than older properties. My 1930's house sits around 50%, no extractor fans, often leave washing drying on rads etc.

Metal or plastic window frames? I find metal suffer far more with condensation.

How many people live in the property? Breathing exhales moisture, any dogs?

paul.deitch

2,152 posts

264 months

Saturday 19th October
quotequote all
Try opening the windows for 10 minutes.

x404

44 posts

146 months

Saturday 19th October
quotequote all
We get a similar issue. Over the past few weeks with all the rain, our RH upstairs has been in the 70s% - and like you, we always have the windows open, or vented when temp/weather allows. Several days I've had to mop windows in the morning (always the case on cold winter mornings). The upstairs bathrooms have fans and we always open the windows. We never, ever dry clothes upstairs. Definetly no leaks either, we complete re-plumbed the place, I know where every pipe and cable is located!

This issue only happens in the old 1970s part of the house (all upstairs and half downstairs). We built a large new build section (including kitchen) about 10 years ago, which is obviously up to modern standards, and it never suffers in this way - there is never any condensation on the acres of glass we have in it (aluminium windows and bi-folds, and uPVC skylights), even after cooking or if we dry a few towels on radiators in the freezing depths of winter, yet windows upstairs in the winter mornings always have condensation inside. We have a large north facing non-windowed wall which I think often contributes to the issues.

Our neighbour thinks some of the properties didn't have their window cavity closures installed, so this add to the problem, especially with window condensation (I'm not a builder, so it's not my area of expertise, so I've no idea if this could cause, or exacerbate the issue).

Edited by x404 on Saturday 19th October 13:44

98elise

Original Poster:

28,183 posts

168 months

Saturday 19th October
quotequote all
megaphone said:
When was the house built? I find 'new builds' have more issues than older properties. My 1930's house sits around 50%, no extractor fans, often leave washing drying on rads etc.

Metal or plastic window frames? I find metal suffer far more with condensation.

How many people live in the property? Breathing exhales moisture, any dogs?
Original house 1960's, extended in 2005. UPVC double glazed.

4 adults no pets.

98elise

Original Poster:

28,183 posts

168 months

Saturday 19th October
quotequote all
paul.deitch said:
Try opening the windows for 10 minutes.
We open them for much longer than that. Yesterday (before the dehumidifier arrived) they were open for most of the day.

What's annoying is when I look at other houses in the area none have condensation in the mornings, and hardly anyone else is venting their house. I have to use a window vac to see out of mine!

It was nice to get up this morning and not have to vac every window in the house. RH hasn't moved below 67% though.

Edited by 98elise on Saturday 19th October 14:01

Sheepshanks

34,970 posts

126 months

Saturday 19th October
quotequote all
x404 said:
We get a similar issue. Over the past few weeks with all the rain, our RH upstairs has been in the 70s% - and like you, we always have the windows open, or vented when temp/weather allows. Several days I've had to mop windows in the morning (always the case on cold winter mornings). The upstairs bathrooms have fans and we always open the windows. We never, ever dry clothes upstairs. Definetly no leaks either, we complete re-plumbed the place, I know where every pipe and cable is located!

This issue only happens in the old 1970s part of the house (all upstairs and half downstairs). We built a large new build section (including kitchen) about 10 years ago, which is obviously up to modern standards, and it never suffers in this way - there is never any condensation on the acres of glass we have in it (aluminium windows and bi-folds, and uPVC skylights), even after cooking or if we dry a few towels on radiators in the freezing depths of winter, yet windows upstairs in the winter mornings always have condensation inside. We have a large north facing non-windowed wall which I think often contributes to the issues.

Our neighbour thinks some of the properties didn't have their window cavity closures installed, so this add to the problem, especially with window condensation (I'm not a builder, so it's not my area of expertise, so I've no idea if this could cause, or exacerbate the issue).
We live in a crap built 60’s house and used to have bad condensation - windows and window reveals would be soaking in the morning. Had old 12mm uPVC windows.

We had a big extension and refurb and as part of that had all the windows changed. Nothing fancy, just 20mm uPVC, and now it doesn’t happen at all. Indeed on Wed and Thurs nights this week we had tremendous condensation on the outside of all the windows. Oddly nothing last night so the conditions that cause that must be very marginal.

x404

44 posts

146 months

Saturday 19th October
quotequote all
98elise said:
We open them for much longer than that. Yesterday (before the dehumidifier arrived) they were open for most of the day.

What's annoying is when I look at other houses in the area none have condensation in the mornings, and hardly anyone else is venting their house. I have to use a window vac to see out of mine!

It was nice to get up this morning and not have to vac every window in the house.

Edited by 98elise on Saturday 19th October 13:59
That is exactly our experience too, including opening the windows for decent periods. A couple of neighbours have similar issues, but most others don't, which is why I think it is a fault with the existing build/cavity.

Sheepshanks

34,970 posts

126 months

Saturday 19th October
quotequote all
x404 said:
98elise said:
We open them for much longer than that. Yesterday (before the dehumidifier arrived) they were open for most of the day.

What's annoying is when I look at other houses in the area none have condensation in the mornings, and hardly anyone else is venting their house. I have to use a window vac to see out of mine!

It was nice to get up this morning and not have to vac every window in the house.

Edited by 98elise on Saturday 19th October 13:59
That is exactly our experience too, including opening the windows for decent periods. A couple of neighbours have similar issues, but most others don't, which is why I think it is a fault with the existing build/cavity.
Ideally you’re supposed to open everything up for 5 mins every hour - so you change the air but don’t drop the temp of the fabric of the building. Not very practical though.

SlimJim16v

6,098 posts

150 months

Saturday 19th October
quotequote all
You also need to heat the house. Autumn and spring are the worst. Not cold enough to have the heating on fully.

FMOB

1,994 posts

19 months

Saturday 19th October
quotequote all
Try Positive Input Ventilation as per the linked thread.

I have such a system and it just sorted out the issues, no fuss, no drama or huge electricity bills.

The biggest issue will be cutting a suitable hole in the ceiling, I have no concerns drilling/cutting holes in walls but the ceiling just felt wrong, no idea why.

98elise

Original Poster:

28,183 posts

168 months

Saturday 19th October
quotequote all
FMOB said:
Try Positive Input Ventilation as per the linked thread.

I have such a system and it just sorted out the issues, no fuss, no drama or huge electricity bills.

The biggest issue will be cutting a suitable hole in the ceiling, I have no concerns drilling/cutting holes in walls but the ceiling just felt wrong, no idea why.
Our house is a chalet bungalow so I have the option of walls or ceilings.

FMOB

1,994 posts

19 months

Saturday 19th October
quotequote all
98elise said:
FMOB said:
Try Positive Input Ventilation as per the linked thread.

I have such a system and it just sorted out the issues, no fuss, no drama or huge electricity bills.

The biggest issue will be cutting a suitable hole in the ceiling, I have no concerns drilling/cutting holes in walls but the ceiling just felt wrong, no idea why.
Our house is a chalet bungalow so I have the option of walls or ceilings.
Then in the ceiling at the top of stairs is probably the best spot, these devices work by forcing air changes in the property i.e. air in the loft is forced into the living space and leaks away through the fabric of the house. You could go the whole hog with Mechanical Ventilation Heat Recovery (MVHR), plenty of scope for cutting holes in everything with that.

In your chalet bunglow, I would guess you have solid concrete floors downstairs rather than a suspended floor and air bricks.

98elise

Original Poster:

28,183 posts

168 months

Saturday 19th October
quotequote all
FMOB said:
98elise said:
FMOB said:
Try Positive Input Ventilation as per the linked thread.

I have such a system and it just sorted out the issues, no fuss, no drama or huge electricity bills.

The biggest issue will be cutting a suitable hole in the ceiling, I have no concerns drilling/cutting holes in walls but the ceiling just felt wrong, no idea why.
Our house is a chalet bungalow so I have the option of walls or ceilings.
Then in the ceiling at the top of stairs is probably the best spot, these devices work by forcing air changes in the property i.e. air in the loft is forced into the living space and leaks away through the fabric of the house. You could go the whole hog with Mechanical Ventilation Heat Recovery (MVHR), plenty of scope for cutting holes in everything with that.

In your chalet bunglow, I would guess you have solid concrete floors downstairs rather than a suspended floor and air bricks.
Yes solid floors downstairs.

ATG

21,319 posts

279 months

Saturday 19th October
quotequote all
Air's capacity to hold water varies very significantly over small temperature changes, so if you take air at, say, 70% RH and heat it by a couple of degrees C, you'd see its relative humidity drop to something like 63%.

And of course that works both ways. If your window glass's inner surface is cold and room air stays in contact with it long enough to cool down by several degrees, then that air's relative humidity can shoot up, reach saturation point, and then water starts condensing out.

98elise

Original Poster:

28,183 posts

168 months

Saturday 19th October
quotequote all
FMOB said:
98elise said:
FMOB said:
Try Positive Input Ventilation as per the linked thread.

I have such a system and it just sorted out the issues, no fuss, no drama or huge electricity bills.

The biggest issue will be cutting a suitable hole in the ceiling, I have no concerns drilling/cutting holes in walls but the ceiling just felt wrong, no idea why.
Our house is a chalet bungalow so I have the option of walls or ceilings.
Then in the ceiling at the top of stairs is probably the best spot, these devices work by forcing air changes in the property i.e. air in the loft is forced into the living space and leaks away through the fabric of the house. You could go the whole hog with Mechanical Ventilation Heat Recovery (MVHR), plenty of scope for cutting holes in everything with that.

In your chalet bunglow, I would guess you have solid concrete floors downstairs rather than a suspended floor and air bricks.
Yes solid floors downstairs.

The dehumidifier has been running nearly 24 hours now and is still showing about 70% humidity (and the "WET" indicator is on). If it carries on like this then there must be a bigger issue somewhere.

I'm going to let it run 24/7 for a few days and see if it gets any better, then start running it for shorter periods and see if it keeps the condensation down.





Jeremy-75qq8

1,177 posts

99 months

Saturday 19th October
quotequote all
We have an indoor pool and we run it at 65% in the summer and 60 % in winter.

I don't know the house humidity but it is always lower than the pool given how if feels when we enter.