Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

"Grimly Curmudgeon" wrote in message
...
Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."

Seems clear enough to me.
Do you need some help with the explanation?

dennis@home wrote:


"Grimly Curmudgeon" wrote in message
...
Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."

Seems clear enough to me.
Do you need some help with the explanation?

But did you see that there were TWO patches on the ceiling?

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

On Jun 4, 9:58 pm, "dennis@home"
wrote:
"Grimly Curmudgeon" wrote in message

...

Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."

Seems clear enough to me.
Do you need some help with the explanation?

Yes. I would expect the heat to cause any moisture to evaporate - not
condense!

"Rod" wrote in message
...
dennis@home wrote:


"Grimly Curmudgeon" wrote in message
...
Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."

Seems clear enough to me.
Do you need some help with the explanation?

But did you see that there were TWO patches on the ceiling?

I didn't see it at all, however I would expect one either side.

dennis@home wrote:

I didn't see it at all, however I would expect one either side.

One round the ceiling light fitting - the other to one side - almost a
figure-of-eight. IMHO there must be two drips (or something) to cause
that pattern.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

"Rod" wrote in message
...
dennis@home wrote:

I didn't see it at all, however I would expect one either side.

One round the ceiling light fitting - the other to one side - almost a
figure-of-eight. IMHO there must be two drips (or something) to cause
that pattern.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Yes but what were the chances of water drips droppig on/around the light?
million to one chance.

I reckon it was bathroom at one time?

"George" wrote in message
...

"Rod" wrote in message
...
dennis@home wrote:

I didn't see it at all, however I would expect one either side.

One round the ceiling light fitting - the other to one side - almost a
figure-of-eight. IMHO there must be two drips (or something) to cause
that pattern.

--

Yes but what were the chances of water drips droppig on/around the light?
million to one chance.

I reckon it was bathroom at one time?



Far more likely that the slight heat from the lamp causes convection
currents and something is making cold spots.. condensation.
Condensation causes most damp problems. Made worse when the unknowing add
heat in the form of bottled gas heaters.

dennis@home wrote:

Far more likely that the slight heat from the lamp causes convection
currents and something is making cold spots.. condensation.
Condensation causes most damp problems. Made worse when the unknowing
add heat in the form of bottled gas heaters.


But it must have fitted properly with one of those fire resistant
upside-down plantpot things. And that would inhibit any such convection.
Surely... :-)

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

"Martin Bonner" wrote in message
...
On Jun 4, 9:58 pm, "dennis@home"
wrote:
"Grimly Curmudgeon" wrote in message

...

Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."

Seems clear enough to me.
Do you need some help with the explanation?

Yes. I would expect the heat to cause any moisture to evaporate - not
condense!

I didn't see the show, so this is pure supposition. If, as implied in the
statement, the ceiling is colder than the room air temperature then a warm
light could draw up moist air and that impinging on the cold ceiling surface
could result in condensation.

Colin Bignell

nightjar cpb@ wrote:
"Martin Bonner" wrote in message
...
On Jun 4, 9:58 pm, "dennis@home"
wrote:
"Grimly Curmudgeon" wrote in message

...

Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
Seems clear enough to me.
Do you need some help with the explanation?
Yes. I would expect the heat to cause any moisture to evaporate - not
condense!

I didn't see the show, so this is pure supposition. If, as implied in the
statement, the ceiling is colder than the room air temperature then a warm
light could draw up moist air and that impinging on the cold ceiling surface
could result in condensation.

How does a warm light draw up cold air? I would expect a source of heat
at the ceiling to create a layer of warmer air next to the ceiling
(remember that heating a gas causes it to expand).

nightjar cpb@ wrote:
"Martin Bonner" wrote in message
...
On Jun 4, 9:58 pm, "dennis@home"
wrote:
"Grimly Curmudgeon" wrote in message

...

Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
Seems clear enough to me.
Do you need some help with the explanation?
Yes. I would expect the heat to cause any moisture to evaporate - not
condense!

I didn't see the show, so this is pure supposition. If, as implied in the
statement, the ceiling is colder than the room air temperature then a warm
light could draw up moist air and that impinging on the cold ceiling surface
could result in condensation.

Colin Bignell


Attic room.
Ceiling goes across below the apex of the roof. At a guess about four
feet wide and ten feet long. (Even if not accurate it gives a working idea.)
Somewhere near middle of ceiling, downlighter. Not sure if LV or mains.
One ring of damp around the hole where the light fitting is inserted
into the ceiling. A second to one side - I'd guess 45 degrees to
direction of rafters away from first ring.
There is a Velux (or similar).
Roof apparently good condition concrete tiles.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

"Rod" wrote in message
...
nightjar cpb@ wrote:
"Martin Bonner" wrote in message
...
On Jun 4, 9:58 pm, "dennis@home"
wrote:
"Grimly Curmudgeon" wrote in message

...

Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
Seems clear enough to me.
Do you need some help with the explanation?
Yes. I would expect the heat to cause any moisture to evaporate - not
condense!

I didn't see the show, so this is pure supposition. If, as implied in the
statement, the ceiling is colder than the room air temperature then a
warm light could draw up moist air and that impinging on the cold ceiling
surface could result in condensation.

Colin Bignell
Attic room.
Ceiling goes across below the apex of the roof. At a guess about four feet
wide and ten feet long. (Even if not accurate it gives a working idea.)
Somewhere near middle of ceiling, downlighter.

Ah. Given that the downlighter probably allows air flow through to the apex
space, I would imagine then that hot air is rising into the apex drawing
colder air from the room below.

Tim

"Rod" wrote in message
Attic room.
Ceiling goes across below the apex of the roof. At a guess about four
feet wide and ten feet long. (Even if not accurate it gives a working
idea.)
Somewhere near middle of ceiling, downlighter. Not sure if LV or mains.
One ring of damp around the hole where the light fitting is inserted
into the ceiling. A second to one side - I'd guess 45 degrees to
direction of rafters away from first ring.
There is a Velux (or similar).
Roof apparently good condition concrete tiles.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Concrete tiles?

Lets just Kirsty was right because she'd have looked rather stupid if she
was talking ********.
These progrs are recorded and then aired are they not? so therefore she'd
have got an opinion on the damp also.

George wrote:
"Rod" wrote in message
Attic room.
Ceiling goes across below the apex of the roof. At a guess about four
feet wide and ten feet long. (Even if not accurate it gives a working
idea.)
Somewhere near middle of ceiling, downlighter. Not sure if LV or mains.
One ring of damp around the hole where the light fitting is inserted
into the ceiling. A second to one side - I'd guess 45 degrees to
direction of rafters away from first ring.
There is a Velux (or similar).
Roof apparently good condition concrete tiles.

--
Rod
Concrete tiles?

Lets just Kirsty was right because she'd have looked rather stupid if she
was talking ********.
These progrs are recorded and then aired are they not? so therefore she'd
have got an opinion on the damp also.



hmmmm I think you may be giving the program makers way to much credit.

Someone may indeed have got an opinion but it does not mean that the
presenter understands it or presents a good explanation.

OP
/Quote
Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
/end quote

This is indeed ********. The lights getting hot in themselves does not
cause the moisture to condense. It being cold and having hot lights does
not necessarily cause moisture to condense.

Having a localised increase in water vapour, and a route into a cold space
(with no ventilation) will result in condensation forming in the cold space.

It does sound like someone has said the patches are due to A, B and C... but
her interpretation and communication of this is lacking.
However having not seen the program I do not know exactly what she is
referring to in the context of the OP's quote so some of this is conjecture.

cheers

David

"Gib Bogle" wrote in message
...


How does a warm light draw up cold air? I would expect a source of heat
at the ceiling to create a layer of warmer air next to the ceiling
(remember that heating a gas causes it to expand).

The hot air then hits the cold roof and cools and falls to be replaced by
more air drawn up.
If it were *well* insulated what you said might be true.

On Jun 5, 10:50 am, "Tim Downie"
wrote:
"Rod" wrote in message

...



nightjar cpb@ wrote:
"Martin Bonner" wrote in message
...
On Jun 4, 9:58 pm, "dennis@home"
wrote:
"Grimly Curmudgeon" wrote in message

. ..

Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
Seems clear enough to me.
Do you need some help with the explanation?
Yes. I would expect the heat to cause any moisture to evaporate - not
condense!

I didn't see the show, so this is pure supposition. If, as implied in the
statement, the ceiling is colder than the room air temperature then a
warm light could draw up moist air and that impinging on the cold ceiling
surface could result in condensation.

Colin Bignell
Attic room.
Ceiling goes across below the apex of the roof. At a guess about four feet
wide and ten feet long. (Even if not accurate it gives a working idea.)
Somewhere near middle of ceiling, downlighter.

Ah. Given that the downlighter probably allows air flow through to the apex
space, I would imagine then that hot air is rising into the apex drawing
colder air from the room below.

Tim

Or hot air is rising into the apex and then condensing on a cold
surface and dripping back onto the ceiling.

MBQ

On 5 Jun, 12:13, "dennis@home" wrote:
"Gib Bogle" wrote in message

...

How does a warm light draw up cold air? I would expect a source of heat
at the ceiling to create a layer of warmer air next to the ceiling
(remember that heating a gas causes it to expand).

The hot air then hits the cold roof

How does the light (up high) heat the air (low down) sufficiently to
cause the temperature inversion necessary for convection to start? If
the light heats anything, it will be the air up high near the light,
thus creating a layer of warm stagnant air at the top.

"Andy Dingley" wrote in message
...
On 5 Jun, 12:13, "dennis@home" wrote:
"Gib Bogle" wrote in message

...

How does a warm light draw up cold air? I would expect a source of
heat
at the ceiling to create a layer of warmer air next to the ceiling
(remember that heating a gas causes it to expand).

The hot air then hits the cold roof

How does the light (up high) heat the air (low down) sufficiently to
cause the temperature inversion necessary for convection to start? If
the light heats anything, it will be the air up high near the light,
thus creating a layer of warm stagnant air at the top.

chaos theory?
Are there no draughts, or any other irregularity to start it off?

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "dennis@home"
saying something like:



"Grimly Curmudgeon" wrote in message
...
Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."

Seems clear enough to me.
Do you need some help with the explanation?

Not from you I don't. I'd like some more explanation from the lovely
Kirstie. Could you put a dress and fake boobs on and pretend to be her?
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember DM saying
something like:

hmmmm I think you may be giving the program makers way to much credit.

Someone may indeed have got an opinion but it does not mean that the
presenter understands it or presents a good explanation.

OP
/Quote
Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
/end quote

This is indeed ********. The lights getting hot in themselves does not
cause the moisture to condense. It being cold and having hot lights does
not necessarily cause moisture to condense.

Having a localised increase in water vapour, and a route into a cold space
(with no ventilation) will result in condensation forming in the cold space.

It does sound like someone has said the patches are due to A, B and C... but
her interpretation and communication of this is lacking.
However having not seen the program I do not know exactly what she is
referring to in the context of the OP's quote so some of this is conjecture.

That's pretty much exactly it, I believe. It's possible that drips were
forming on the rafter above the light, but who knows.

It just sounded like so much ******** when she spouted it - now we'll
have a whole generation of TV property programme viewers and/or dodgy
builders who will nod knowledgeably and say something like, "It's the
ceiling light that's condensing the damp, luv", whenever they spot a
patch on the ceiling.
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

"Rod" wrote in message
...
nightjar cpb@ wrote:
"Martin Bonner" wrote in message
...
On Jun 4, 9:58 pm, "dennis@home"
wrote:
"Grimly Curmudgeon" wrote in message

...

Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
Seems clear enough to me.
Do you need some help with the explanation?
Yes. I would expect the heat to cause any moisture to evaporate - not
condense!

I didn't see the show, so this is pure supposition. If, as implied in the
statement, the ceiling is colder than the room air temperature then a
warm light could draw up moist air and that impinging on the cold ceiling
surface could result in condensation.

Colin Bignell
Attic room.
Ceiling goes across below the apex of the roof. At a guess about four feet
wide and ten feet long. (Even if not accurate it gives a working idea.)
Somewhere near middle of ceiling, downlighter. Not sure if LV or mains.
One ring of damp around the hole where the light fitting is inserted into
the ceiling.

That is more or less what I assumed from the comment, although I did not
know the downlighter was in a ceiling void directly below the roof. I also
made the assumption that the downlighter can vent freely to the space above
the ceiling. In that case, the lamp heats the air above it, which rises.
That draws more air in from the room, creating a rising column of air. The
column will be wider than the fitting, so some of the rising air will hit
the ceiling around the fitting. If that is cooler than the dew point of the
rising air, you will get condensation around the fitting. If insulation has
been cut back to avoid it impinging on the fitting, the ceiling around the
fitting might well be cold enough.

A second to one side - I'd guess 45 degrees to direction of rafters away
from first ring.

I would not expect that to be a direct result of the lamp, although there
could be some secondary effects from drawing moist air into the ceiling
void. Fitting a fire resistant enclosure above the fitting ought to cure the
first problem and might sort the second.

Colin Bignell

"Gib Bogle" wrote in message
...
nightjar cpb@ wrote:
"Martin Bonner" wrote in message
...
On Jun 4, 9:58 pm, "dennis@home"
wrote:
"Grimly Curmudgeon" wrote in message

...

Kirstie Allsopp, in Loc, loc, loc...
"It's cold up there and these ceiling lights get hot and are causing
moisture to condense around them on the ceiling..."
Seems clear enough to me.
Do you need some help with the explanation?
Yes. I would expect the heat to cause any moisture to evaporate - not
condense!

I didn't see the show, so this is pure supposition. If, as implied in the
statement, the ceiling is colder than the room air temperature then a
warm light could draw up moist air and that impinging on the cold ceiling
surface could result in condensation.

How does a warm light draw up cold air? I would expect a source of heat
at the ceiling to create a layer of warmer air next to the ceiling
(remember that heating a gas causes it to expand).

I'm not sure where you get the idea I said it would draw up cold air. I said
it could draw up moist air, which is more usually warm than cold. See my
other reply posting for a more detailed explanation of how I would expect it
to work.

Colin Bignell

nightjar cpb@ wrote:

I would not expect that to be a direct result of the lamp, although there
could be some secondary effects from drawing moist air into the ceiling
void. Fitting a fire resistant enclosure above the fitting ought to cure the
first problem and might sort the second.


I agree that the lamp should have a "plantpot", that if it had one and
the cause was as described (warm, moist air rising past the lamp and
condensing), that would fix it. But I actually think there is a minor
roof problem.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Rod wrote:
nightjar cpb@ wrote:

I would not expect that to be a direct result of the lamp, although
there could be some secondary effects from drawing moist air into the
ceiling void. Fitting a fire resistant enclosure above the fitting
ought to cure the first problem and might sort the second.


I agree that the lamp should have a "plantpot", that if it had one and
the cause was as described (warm, moist air rising past the lamp and
condensing), that would fix it. But I actually think there is a minor
roof problem.


That would not really fix anything if the light is not on you would just get
condensation inside the pot. However if the light is on , and is a nice LV
halogen then the pot might just get warm enough to prevent condensation
forming.

cheers

David

DM wrote:
Rod wrote:
nightjar cpb@ wrote:

I would not expect that to be a direct result of the lamp, although
there could be some secondary effects from drawing moist air into the
ceiling void. Fitting a fire resistant enclosure above the fitting
ought to cure the first problem and might sort the second.


I agree that the lamp should have a "plantpot", that if it had one and
the cause was as described (warm, moist air rising past the lamp and
condensing), that would fix it. But I actually think there is a minor
roof problem.


That would not really fix anything if the light is not on you would just
get condensation inside the pot. However if the light is on , and is a
nice LV halogen then the pot might just get warm enough to prevent
condensation forming.

cheers


Possibly. But I figured that without a significant airflow *through* the
fitting, any airflow up into (moist air) and down out of (air which has
been dried by condensing onto the plantpot) would be minimal - and would
certainly not spread across any the rest of the ceiling. (It is possible
that the airflow is caused almost entirely by wind over the roof sucking
air upwards. That too would be massively reduced by a plantpot.) Of
course, it all depends on the conductivity of the plantpot.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org