HI,

I have a 15 year old house. I've done all the home improvements including
new double glazing (3 years ago) and 12 inches of loft insulation. Only
thing left now is cavity insulation.

Now I was plagued by black mould and condensation in all of the upstairs
windows when I had the old windows. These were hardwood frames with sealed
double glazing units inserted like a single pane of glass.

There are three windows in total upstairs, front bedroom, back bedroom and
landing.

I had specified trickle vents and grade A energy rating glass for the new
double glazing due to the condensation problems I had.

I am still plagued by condensation when the outside is cold even with the
new double glazing.

Its so bad that there are pools of water on the window shelves. I of course
ended up with black mould again on the emulsioned plasterboard where it
meets the wooden window shelf.

I've scraped off the mould and painted benzalkonium chloride on in an effort
to kill the mould and prevent regrowth.

Last year I invested in a dehumidifer thinking that it was the moisture from
sleeping peoples breath that was the cause as the downstairs windows did not
suffer from condensation

Now that the outside is colder, I had it running all the time to dry out the
air and it did reduce the condensation significantly.

But the other half is complaining she is waking up with a headache due to
dehydration and is gasping for water all day whilst at work.

I've changed the humidistat to 30% humidity on the dehumidifier. This is on
the landing
..
The other half's headaches have improved but the condensation has come back
somewhat, with a thin smearing at the bootom of the window panes

I am keen to avoid a return of the black mould as I have asthma. I have
noticed that the plasterboard in the two corners where wood window shelf
meets the UPVC window feels cold to the touch. Although there is no mould
(yet) the benzalkonium chloride I painted on seems to have become tacky.

How can I banish this condensation once and for all?

Stephen.

"Stephen" wrote in message
o.uk...
HI,

I have a 15 year old house. I've done all the home improvements including
new double glazing (3 years ago) and 12 inches of loft insulation. Only
thing left now is cavity insulation.

Now I was plagued by black mould and condensation in all of the upstairs
windows when I had the old windows. These were hardwood frames with sealed
double glazing units inserted like a single pane of glass.

There are three windows in total upstairs, front bedroom, back bedroom and
landing.

I had specified trickle vents and grade A energy rating glass for the new
double glazing due to the condensation problems I had.

I am still plagued by condensation when the outside is cold even with the
new double glazing.

Its so bad that there are pools of water on the window shelves. I of
course ended up with black mould again on the emulsioned plasterboard
where it meets the wooden window shelf.

I've scraped off the mould and painted benzalkonium chloride on in an
effort to kill the mould and prevent regrowth.

Last year I invested in a dehumidifer thinking that it was the moisture
from sleeping peoples breath that was the cause as the downstairs windows
did not suffer from condensation

Now that the outside is colder, I had it running all the time to dry out
the air and it did reduce the condensation significantly.

But the other half is complaining she is waking up with a headache due to
dehydration and is gasping for water all day whilst at work.

I've changed the humidistat to 30% humidity on the dehumidifier. This is
on the landing

Bloody hell, mines set to 70%.

.
The other half's headaches have improved but the condensation has come
back somewhat, with a thin smearing at the bootom of the window panes

I am keen to avoid a return of the black mould as I have asthma. I have
noticed that the plasterboard in the two corners where wood window shelf
meets the UPVC window feels cold to the touch. Although there is no mould
(yet) the benzalkonium chloride I painted on seems to have become tacky.

How can I banish this condensation once and for all?


What you need is to open the windows a bit.

Then you may need to have a little more heat.

On Mon, 7 Nov 2011 21:44:12 -0000, Stephen wrote:

I have noticed that the plasterboard in the two corners where wood
window shelf meets the UPVC window feels cold to the touch.

When you did the windows did you ensure there was no cold bridge or a
void with a draft from the outside in it?

How can I banish this condensation once and for all?

Reduce the moisture content of the air inside. Where is this mositure
coming from? One assumes that the bathroom and kitchen have
extractors and they are used during and after bathing/cooking. Do you
dry clothes indoors? Try to remove/eliminate the moisture at source.

After that reduce the vapour in the air either by ventilation or by a
dehumdifier. Ventilation is the prefered option as that brings fresh
air into the house.

--
Cheers
Dave.

On 07/11/2011 22:54, Dave Liquorice wrote:
On Mon, 7 Nov 2011 21:44:12 -0000, Stephen wrote:

I have noticed that the plasterboard in the two corners where wood
window shelf meets the UPVC window feels cold to the touch.

When you did the windows did you ensure there was no cold bridge or a
void with a draft from the outside in it?

How can I banish this condensation once and for all?

Reduce the moisture content of the air inside. Where is this mositure
coming from? One assumes that the bathroom and kitchen have
extractors and they are used during and after bathing/cooking. Do you
dry clothes indoors? Try to remove/eliminate the moisture at source.

After that reduce the vapour in the air either by ventilation or by a
dehumdifier. Ventilation is the prefered option as that brings fresh
air into the house.

Good advice.

Cooking, showering, washing, breathing etc all put dampness in to the air.

You can extract it via extractors, windows or dehumidifiers. Otherwise
it will simply condense on the coolest surfaces in the area.

On Nov 7, 9:44*pm, "Stephen" wrote:
HI,

I have a 15 year old house. I've done all the home improvements including
new double glazing (3 years ago) and 12 inches of loft insulation. Only
thing left now is cavity insulation.

Now I was plagued by black mould and condensation in all of the upstairs
windows when I had the old windows. These were hardwood frames with sealed
double glazing units inserted like a single pane of glass.

There are three windows in total upstairs, front bedroom, back bedroom and
landing.

I had specified trickle vents and grade A energy rating glass for the new
double glazing due to the condensation problems I had.

I am still plagued by condensation when the outside is cold even with the
new double glazing.

Its so bad that there are pools of water on the window shelves. I of course
ended up with black mould again on the emulsioned plasterboard where it
meets the wooden window shelf.

I've scraped off the mould and painted benzalkonium chloride on in an effort
to kill the mould and prevent regrowth.

Last year I invested in a dehumidifer thinking that it was the moisture from
sleeping peoples breath that was the cause as the downstairs windows did not
suffer from condensation

Now that the outside is colder, I had it running all the time to dry out the
air and it did reduce the condensation significantly.

But the other half is complaining she is waking up with a headache due to
dehydration and is gasping for water all day whilst at work.

I've changed the humidistat to 30% humidity on the dehumidifier. This is on
the landing
.
The other half's headaches have improved but the condensation has come back
somewhat, with a thin smearing at the bootom of the window panes

I am keen to avoid a return of the black mould as I have asthma. I have
noticed that the plasterboard in the two corners where wood window shelf
meets the UPVC window feels cold to the touch. Although there is no mould
(yet) the benzalkonium chloride I painted on seems to have become tacky.

How can I banish this condensation once and for all?

Stephen.

You need to tackle humidity at source. Cooker hoods, extractor fans in
shower/bathrooms.

How can I banish this condensation once and for all?


Turn the heating on

In message , Hugh - Was Invisible
writes
On 07/11/2011 22:54, Dave Liquorice wrote:
On Mon, 7 Nov 2011 21:44:12 -0000, Stephen wrote:

I have noticed that the plasterboard in the two corners where wood
window shelf meets the UPVC window feels cold to the touch.

When you did the windows did you ensure there was no cold bridge or a
void with a draft from the outside in it?

How can I banish this condensation once and for all?

Reduce the moisture content of the air inside. Where is this mositure
coming from? One assumes that the bathroom and kitchen have
extractors and they are used during and after bathing/cooking. Do you
dry clothes indoors? Try to remove/eliminate the moisture at source.

After that reduce the vapour in the air either by ventilation or by a
dehumdifier. Ventilation is the prefered option as that brings fresh
air into the house.

Good advice.

Cooking, showering, washing, breathing etc all put dampness in to the air.

You can extract it via extractors, windows or dehumidifiers. Otherwise
it will simply condense on the coolest surfaces in the area.

It rather sounds as though the cavity closure at the window opening is
brick/block allowing cold to bridge from the wall outer leaf.

Last year, I fitted a heat recovery extractor unit to my wife's flat
which had suffered from condensation and mould on North facing outside
walls. So far, so good! No mould to be seen.

It is difficult to judge the effectiveness as tenants change and may
have totally different life styles: eat out/cook in, lots of
showers/prefer the bath etc. We don't have access to the heating bills
either so running costs are not measurable.

regards

--
Tim Lamb

On Mon, 07 Nov 2011 23:36:25 +0000, Hugh - Was Invisible
wrote:

On 07/11/2011 22:54, Dave Liquorice wrote:
On Mon, 7 Nov 2011 21:44:12 -0000, Stephen wrote:

I have noticed that the plasterboard in the two corners where wood
window shelf meets the UPVC window feels cold to the touch.

When you did the windows did you ensure there was no cold bridge or a
void with a draft from the outside in it?

How can I banish this condensation once and for all?

Reduce the moisture content of the air inside. Where is this mositure
coming from? One assumes that the bathroom and kitchen have
extractors and they are used during and after bathing/cooking. Do you
dry clothes indoors? Try to remove/eliminate the moisture at source.

After that reduce the vapour in the air either by ventilation or by a
dehumdifier. Ventilation is the prefered option as that brings fresh
air into the house.

Good advice.

Cooking, showering, washing, breathing etc all put dampness in to the air.

You can extract it via extractors, windows or dehumidifiers. Otherwise
it will simply condense on the coolest surfaces in the area.

Moisture can condense on any surface that is cooler than the ambient
temperature.

I would recommed more ventilation too. Trickle vents are very poor
IMHO.
--
(\__/) M.
(='.'=) Due to the amount of spam posted via googlegroups and
(")_(") their inaction to the problem. I am blocking some articles
posted from there. If you wish your postings to be seen by
everyone you will need use a different method of posting.

What you need to do is buy a half dozen humidity meters from Amazon
(they are only a few quid each) and scatter them around to get a
picture of what is happening. If you have readings above 70% then you
are going to have condensation problems. But beware, whereas digital
meters tend (I think) to be accurate, the analogue ones need to be
calibrated. (Buy a digital one to calibrate them with).

Good luck.

Brendan.

On Nov 7, 9:44*pm, "Stephen" wrote:
HI,

I have a 15 year old house. I've done all the home improvements including
new double glazing (3 years ago) and 12 inches of loft insulation. Only
thing left now is cavity insulation.

Now I was plagued by black mould and condensation in all of the upstairs
windows when I had the old windows. These were hardwood frames with sealed
double glazing units inserted like a single pane of glass.

There are three windows in total upstairs, front bedroom, back bedroom and
landing.

I had specified trickle vents and grade A energy rating glass for the new
double glazing due to the condensation problems I had.

I am still plagued by condensation when the outside is cold even with the
new double glazing.

Its so bad that there are pools of water on the window shelves. I of course
ended up with black mould again on the emulsioned plasterboard where it
meets the wooden window shelf.

I've scraped off the mould and painted benzalkonium chloride on in an effort
to kill the mould and prevent regrowth.

Last year I invested in a dehumidifer thinking that it was the moisture from
sleeping peoples breath that was the cause as the downstairs windows did not
suffer from condensation

Now that the outside is colder, I had it running all the time to dry out the
air and it did reduce the condensation significantly.

But the other half is complaining she is waking up with a headache due to
dehydration and is gasping for water all day whilst at work.

I've changed the humidistat to 30% humidity on the dehumidifier. This is on
the landing
.
The other half's headaches have improved but the condensation has come back
somewhat, with a thin smearing at the bootom of the window panes

I am keen to avoid a return of the black mould as I have asthma. I have
noticed that the plasterboard in the two corners where wood window shelf
meets the UPVC window feels cold to the touch. Although there is no mould
(yet) the benzalkonium chloride I painted on seems to have become tacky.

How can I banish this condensation once and for all?

Stephen.

a) determine where excess moisture is coming from, and sort it out
b) run the dehumidifier
Ventilation is good in summer, this time of year its a lot more
practical to use the dehumidifier.


NT

On Tue, 08 Nov 2011 11:00:35 +0000, Terry Fields wrote:

Stephen wrote:

I have a 15 year old house. I've done all the home improvements including
new double glazing (3 years ago) and 12 inches of loft insulation. Only
thing left now is cavity insulation.

Now I was plagued by black mould and condensation in all of the upstairs
windows when I had the old windows. These were hardwood frames with sealed
double glazing units inserted like a single pane of glass.

There are three windows in total upstairs, front bedroom, back bedroom and
landing.

I had specified trickle vents and grade A energy rating glass for the new
double glazing due to the condensation problems I had.

I am still plagued by condensation when the outside is cold even with the
new double glazing.

Condensation occurs when the temperature of a surface drops below the
dew point.

For example, if your house is run at 20 degC, and it is 60 percent
humid, there will be (very nearly) 20 x 0.6 = 12 grams of water per
cubic metre. This represents 100 percent humidity at 12 degC, so if
your windows drop below 12 degC on the inside, condensation can form.

There are at least two things you can do, apart from re-engineering
the windows:

Lower the humidity in the house (this will lower the temperature at
which condensation takes place)(this can he helped by keeping moist
air from the kitchen and bathroom out of the rest of the house by
keeping the internal doors closed)

Draw curtains over the windows (this stops the humid air reaching the
window in significant amounts if done properly (no gaps at top,
bottom, or sides).

Terry Fields

Just over a year ago I put up various curtains etc. The front door, which is
fully glazed, gets far more condensation with double net on the door and
curtain over the recess than it ever did when 'naked'; the same applies to
other glazing.
I run the downstairs rooms at ~16 - 18C and upstairs at ~14 - 16C and
there's only me in the house and v. little cooking. I assume that the extra
condesation is due to the glazing (20-yo double) being much colder.
The advantage is that the moisture can be mopped up and got rid of and that
the other surfaces are a bit warmer than they were and so get less
condensation.
--
Peter.
The gods will stay away
whilst religions hold sway

NT wrote:
On Nov 7, 9:44 pm, "Stephen" wrote:
HI,

I have a 15 year old house. I've done all the home improvements
including new double glazing (3 years ago) and 12 inches of loft
insulation. Only thing left now is cavity insulation.

Now I was plagued by black mould and condensation in all of the
upstairs windows when I had the old windows. These were hardwood
frames with sealed double glazing units inserted like a single pane
of glass.

There are three windows in total upstairs, front bedroom, back
bedroom and landing.

I had specified trickle vents and grade A energy rating glass for
the new double glazing due to the condensation problems I had.

I am still plagued by condensation when the outside is cold even
with the new double glazing.

Its so bad that there are pools of water on the window shelves. I of
course ended up with black mould again on the emulsioned
plasterboard where it meets the wooden window shelf.

I've scraped off the mould and painted benzalkonium chloride on in
an effort to kill the mould and prevent regrowth.

Last year I invested in a dehumidifer thinking that it was the
moisture from sleeping peoples breath that was the cause as the
downstairs windows did not suffer from condensation

Now that the outside is colder, I had it running all the time to dry
out the air and it did reduce the condensation significantly.

But the other half is complaining she is waking up with a headache
due to dehydration and is gasping for water all day whilst at work.

I've changed the humidistat to 30% humidity on the dehumidifier.
This is on the landing
.
The other half's headaches have improved but the condensation has
come back somewhat, with a thin smearing at the bootom of the window
panes

I am keen to avoid a return of the black mould as I have asthma. I
have noticed that the plasterboard in the two corners where wood
window shelf meets the UPVC window feels cold to the touch. Although
there is no mould (yet) the benzalkonium chloride I painted on seems
to have become tacky.

How can I banish this condensation once and for all?

Stephen.

a) determine where excess moisture is coming from, and sort it out
b) run the dehumidifier


Ventilation is good in summer, this time of year its a lot more
practical to use the dehumidifier.

Why is that if you are removing at source?

--
Adam

On 07/11/2011 21:44, Stephen wrote:
HI,

I have a 15 year old house. I've done all the home improvements including
new double glazing (3 years ago) and 12 inches of loft insulation. Only
thing left now is cavity insulation.

Now I was plagued by black mould and condensation in all of the upstairs
windows when I had the old windows. These were hardwood frames with sealed
double glazing units inserted like a single pane of glass.

There are three windows in total upstairs, front bedroom, back bedroom and
landing.

I had specified trickle vents and grade A energy rating glass for the new
double glazing due to the condensation problems I had.

I am still plagued by condensation when the outside is cold even with the
new double glazing.

Its so bad that there are pools of water on the window shelves. I of course
ended up with black mould again on the emulsioned plasterboard where it
meets the wooden window shelf.

I've scraped off the mould and painted benzalkonium chloride on in an effort
to kill the mould and prevent regrowth.

Last year I invested in a dehumidifer thinking that it was the moisture from
sleeping peoples breath that was the cause as the downstairs windows did not
suffer from condensation

Now that the outside is colder, I had it running all the time to dry out the
air and it did reduce the condensation significantly.

But the other half is complaining she is waking up with a headache due to
dehydration and is gasping for water all day whilst at work.

I've changed the humidistat to 30% humidity on the dehumidifier. This is on
the landing
.
The other half's headaches have improved but the condensation has come back
somewhat, with a thin smearing at the bootom of the window panes

I am keen to avoid a return of the black mould as I have asthma. I have
noticed that the plasterboard in the two corners where wood window shelf
meets the UPVC window feels cold to the touch. Although there is no mould
(yet) the benzalkonium chloride I painted on seems to have become tacky.

How can I banish this condensation once and for all?

Stephen.



Leave the internal doors open and a window or two so air can circulate
and remove the moisture. The problem could be steam from a shower?
Something somewhere is generating moisture.

On Nov 8, 8:19*pm, "ARWadsworth"
wrote:
NT wrote:
On Nov 7, 9:44 pm, "Stephen" wrote:
HI,

I have a 15 year old house. I've done all the home improvements
including new double glazing (3 years ago) and 12 inches of loft
insulation. Only thing left now is cavity insulation.

Now I was plagued by black mould and condensation in all of the
upstairs windows when I had the old windows. These were hardwood
frames with sealed double glazing units inserted like a single pane
of glass.

There are three windows in total upstairs, front bedroom, back
bedroom and landing.

I had specified trickle vents and grade A energy rating glass for
the new double glazing due to the condensation problems I had.

I am still plagued by condensation when the outside is cold even
with the new double glazing.

Its so bad that there are pools of water on the window shelves. I of
course ended up with black mould again on the emulsioned
plasterboard where it meets the wooden window shelf.

I've scraped off the mould and painted benzalkonium chloride on in
an effort to kill the mould and prevent regrowth.

Last year I invested in a dehumidifer thinking that it was the
moisture from sleeping peoples breath that was the cause as the
downstairs windows did not suffer from condensation

Now that the outside is colder, I had it running all the time to dry
out the air and it did reduce the condensation significantly.

But the other half is complaining she is waking up with a headache
due to dehydration and is gasping for water all day whilst at work.

I've changed the humidistat to 30% humidity on the dehumidifier.
This is on the landing
.
The other half's headaches have improved but the condensation has
come back somewhat, with a thin smearing at the bootom of the window
panes

I am keen to avoid a return of the black mould as I have asthma. I
have noticed that the plasterboard in the two corners where wood
window shelf meets the UPVC window feels cold to the touch. Although
there is no mould (yet) the benzalkonium chloride I painted on seems
to have become tacky.

How can I banish this condensation once and for all?

Stephen.

a) determine where excess moisture is coming from, and sort it out
b) run the dehumidifier
Ventilation is good in summer, this time of year its a lot more
practical to use the dehumidifier.

Why is that if you are removing at source?

If you can reduce damp enough without a dh, fine, but often thats not
the case.


NT

On Tue, 08 Nov 2011 16:40:34 +0000, Terry Fields wrote:

PeterC wrote:

Just over a year ago I put up various curtains etc. The front door, which is
fully glazed, gets far more condensation with double net on the door and
curtain over the recess than it ever did when 'naked'; the same applies to
other glazing.

I'm convinced that this sort of thing is due to a chimney-like effect,
but in reverse.

When the curtains are pulled across, warm air behind them cools due to
the heat loss through the door/window/frame. This sinks down, cooling
as it goes, to emerge as cold air at the bottom.

Meanwhile, warm moist house air enters at the top, cools, and sinks to
the bottom.

The bottom of the door/window/frame is the coolest part as the top is
heated by the room air, and if it falls below the dew point, moisture
will condense out. The colder the outside temperature, the further up
the window etc the condensation starts.

However, heat is also lost by conduction through the frame, and as a
consequence the nearer the frame, the cooler the glass and the greater
likelyhood of condensation. When the curtains are pulled back, the
condensation is typically in a U-shape.

That's why I suggested to the OP that ensuring there are no air gaps
at the sides and bottom (and at the top too, if that can be arranged)
in order to stop this happening by cutting off the airflow.

Terry Fields

Yes, it will work like that to some extent but no where near as fast as a
bare window. Many times on here we've had mention of needing sufficient gap
behind a radiator (and in front, e.g. not putting furniture close) to allow
the air to circulate. The flow is weak over a rad. with up to 60C
difference; a window at max. 30C most of the time would be far less. Adding
even an ill-fitting net curtain will slow that enormously.

I decided to add layers when I noticed the difference made by possibly the
worst addition: vertical blinds. They're loosely mated and have gaps on 3
sides but the difference on a cold morning between inside and windowside was
striking.
Last Winter there was far more ice on the windows than I'd seen in the
previous 19 years; as the glass is obviously much colder than it was without
the extra layers there is less loss of heat. The chimney effect is slowed
and is less than a bare panel, although it still adds some heat to the
window of course.
--
Peter.
The gods will stay away
whilst religions hold sway