Hi


What do you reckon the cause of this mouldy damp patch is?

http://www.wiki.diyfaq.org.uk/index....e=Mould_Basics

The rest of the room is perfectly dry. Its a bedroom, and the window
gets left open right by the damp patch. The window itself is also
mouldy, but the wooden cill between the 2 mouldy thing in the picture
is totally free of it.

If it were due to rain splash, I'd expect
a) the window frame and cill would be affected. Yet neither is
b) the window itself would not be affected, yet it is, equally badly.

I've checked outside, and no visible source of water.


NT

NT wrote:
Hi


What do you reckon the cause of this mouldy damp patch is?

http://www.wiki.diyfaq.org.uk/index....e=Mould_Basics

The rest of the room is perfectly dry. Its a bedroom, and the window
gets left open right by the damp patch. The window itself is also
mouldy, but the wooden cill between the 2 mouldy thing in the picture
is totally free of it.

If it were due to rain splash, I'd expect
a) the window frame and cill would be affected. Yet neither is
b) the window itself would not be affected, yet it is, equally badly.

I've checked outside, and no visible source of water.

What is the wall construction? Is it insulated?

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

NT wrote:
Hi


What do you reckon the cause of this mouldy damp patch is?

http://www.wiki.diyfaq.org.uk/index....e=Mould_Basics

The rest of the room is perfectly dry. Its a bedroom, and the window
gets left open right by the damp patch. The window itself is also
mouldy, but the wooden cill between the 2 mouldy thing in the picture
is totally free of it.

If it were due to rain splash, I'd expect
a) the window frame and cill would be affected. Yet neither is
b) the window itself would not be affected, yet it is, equally badly.

I've checked outside, and no visible source of water.

I can't make out what the widow frame is made of, but my initial
thoughts were that the window is chilling the wall just underneath and
the damp is caused by condensation on the wall. No water ingress at all,
in my oppinion.

Dave

Dave wrote:
NT wrote:
Hi


What do you reckon the cause of this mouldy damp patch is?

http://www.wiki.diyfaq.org.uk/index....e=Mould_Basics

The rest of the room is perfectly dry. Its a bedroom, and the window
gets left open right by the damp patch. The window itself is also
mouldy, but the wooden cill between the 2 mouldy thing in the picture
is totally free of it.

If it were due to rain splash, I'd expect
a) the window frame and cill would be affected. Yet neither is
b) the window itself would not be affected, yet it is, equally badly.

I've checked outside, and no visible source of water.

I can't make out what the widow frame is made of, but my initial
thoughts were that the window is chilling the wall just underneath and
the damp is caused by condensation on the wall. No water ingress at all,
in my oppinion.

Yep. Thats my take too.

Cavity wall, but bridged under the window hence cold. Frames also cold=
mould. But cill is not conductive, so a bit warmer.

Another possibility is plant pots on the cill at some time.


Dave

The Natural Philosopher wrote:
Dave wrote:

Yep. Thats my take too.

Cavity wall, but bridged under the window hence cold. Frames also cold=
mould. But cill is not conductive, so a bit warmer.

Another possibility is plant pots on the cill at some time.


Dave

I wondered whether there is just space under the cill - allowing cold
air onto the back of the plaster(-board?) wall?

--
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

The Natural Philosopher wrote:
Dave wrote:
NT wrote:
Hi


What do you reckon the cause of this mouldy damp patch is?

http://www.wiki.diyfaq.org.uk/index....e=Mould_Basics

The rest of the room is perfectly dry. Its a bedroom, and the window
gets left open right by the damp patch. The window itself is also
mouldy, but the wooden cill between the 2 mouldy thing in the
picture is totally free of it.

If it were due to rain splash, I'd expect
a) the window frame and cill would be affected. Yet neither is
b) the window itself would not be affected, yet it is, equally
badly. I've checked outside, and no visible source of water.

I can't make out what the widow frame is made of, but my initial
thoughts were that the window is chilling the wall just underneath
and the damp is caused by condensation on the wall. No water ingress
at all, in my oppinion.

Yep. Thats my take too.

And mine. Classic condensation scenario.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Natural Philosopher wrote:
Dave wrote:
NT wrote:
Hi


What do you reckon the cause of this mouldy damp patch is?

http://www.wiki.diyfaq.org.uk/index....e=Mould_Basics

The rest of the room is perfectly dry. Its a bedroom, and the window
gets left open right by the damp patch. The window itself is also
mouldy, but the wooden cill between the 2 mouldy thing in the
picture is totally free of it.

If it were due to rain splash, I'd expect
a) the window frame and cill would be affected. Yet neither is
b) the window itself would not be affected, yet it is, equally
badly. I've checked outside, and no visible source of water.

I can't make out what the widow frame is made of, but my initial
thoughts were that the window is chilling the wall just underneath
and the damp is caused by condensation on the wall. No water ingress
at all, in my oppinion.

Yep. Thats my take too.

Cavity wall, but bridged under the window hence cold. Frames also
cold= mould. But cill is not conductive, so a bit warmer.

Another possibility is plant pots on the cill at some time.


Dave

My money's on the exterior cill being sandstone, which is one solid block
about 12 inches wide and 6 inches thick, to cover two complete courses of
brick in height and to cover the entire thickness of the wall plus a few
inches overhang. This is plastered inside, but instead of using render, they
have used browning or bonding, neither of which is suitable for this
application.

To the OP; stick a screwdriver or similar in the wall where it's mouldy - if
it's like damp chalk, you'll need to take it off where the sandstone cill
is, allow to dry for a week or two, then render and skim.

As far as the rest of your post goes WRT the frame being mouldy, I can't
understand it, you say the window itself is mouldy, then a second later say
that neither the cill nor the window are mouldy.

--
Phil L
RSRL Tipster Of The Year 2008

On Jun 24, 10:03*pm, NT wrote:
Hi

What do you reckon the cause of this mouldy damp patch is?

http://www.wiki.diyfaq.org.uk/index....e=Mould_Basics

The rest of the room is perfectly dry. Its a bedroom, and the window
gets left open right by the damp patch. The window itself is also
mouldy, but the wooden cill between the 2 mouldy thing in the picture
is totally free of it.

If it were due to rain splash, I'd expect
a) the window frame and cill would be affected. Yet neither is
b) the window itself would not be affected, yet it is, equally badly.

I've checked outside, and no visible source of water.

NT



The wall is 9" brick & plaster, no insulation. Whether it has a cavity
is currently unknown.
The window sash, window frame and interior cill are timber. The
exterior cill is concrete.
I'm reasonably confident there havent been any plants there.


Rod wrote:
I wondered whether there is just space under the cill - allowing cold
air onto the back of the plaster(-board?) wall?

Fraid I don't understand what you mean there. There's no PB and no gap
that shouldnt exist.


Phil L wrote:

My money's on the exterior cill being sandstone, which is one solid block
about 12 inches wide and 6 inches thick, to cover two complete courses of
brick in height and to cover the entire thickness of the wall plus a few
inches overhang.

spot on, though concrete.


This is plastered inside, but instead of using render, they
have used browning or bonding, neither of which is suitable for this
application.

I believe the interior plastering, bar the final layer, is cement
mortar, for some reason.


To the OP; stick a screwdriver or similar in the wall where it's mouldy - if
it's like damp chalk, you'll need to take it off where the sandstone cill
is, allow to dry for a week or two, then render and skim.

Its solid, no deterioration.


As far as the rest of your post goes WRT the frame being mouldy, I can't
understand it, you say the window itself is mouldy, then a second later say
that neither the cill nor the window are mouldy.

Window is very mouldy, frame is clean, cill is clean, then the wall is
very mouldy.

I have to agree its condensation, but not sure the best way to tackle
the problem yet.


NT