Damp question

Hi,

I recently moved into a house and am confused over a damp issue.
Due to only recently moving in and it being an old house which has been extended I'm trying to establish the construction methods. The bedroom is cavity wall.
In the main bedroom there is a chimney breast in one corner which is showing signs of damp as the wallpaper is bubbling, I have removed this and given it a wipe over. It doesn't feel very damp but the top foot or so is clearly is a different colour.
The room does have a damp feel and one morning I woke up and the double glazed windows were completely wet with condensation.
The chimney has been removed below roof level and not capped as the clay liner can be seen under the loft insulation. There are no signs of water entering the loft.
I'm struggling to find whether the bottom is vented as its behind a lot of cupboards/panelling which will eventually be removed with the refurb. A part of the chimney breast is visible in the garage below the bedroom with no signs of damp but it appears to have has a hole created in side? I'm still unsure why this would be and will try and upload some pics.

I suppose I want to know:
1. Does the exposed chimney liner need to be capped/insulated?
2. If not, do I cover with insulation as found or leave it breathe?
3. Is the amount of condensation and damp feel in room directly linked to uncapped chimney breast in loft?
Chimney does run from garage below through to loft
There is probably no insulation between garage and room above(will be rectified)

Thanks in advance

Not sure if photos are uploaded but this is chimney

Hole created in ground floor of chimney side

If it's condensation, then you are producing it and you need to deal with that.

Use of ventilation, extraction at source from kitchen and bathroom, and heating patterns.

OP, why not post photos of the bedroom including the c/breast and the window?

there's no signs of condensation or water penetration in the loft. so, as above, presumably you are producing any condensation in the bedroom.

leave the loft flue alone - as it is in the pic.

the "hole in the g/f chimney" could be where a previous boiler flue had entered the brick chimney breast?
the yellow staining could be leaked condensate?
or it might have been an ashes clean-out hole for any solid fuel fire above?
looking up the hole, i can see strands of fibre or wisps of insulation - what is it?

is there a blocked up fireplace in the bedroom?

does the house have cavity walls and are the walls rendered?

Thanks for replies.

I managed to speak with previous home owner who said that hole in ground floor chimney was flue for an Aga.

I was stripping wallpaper in the room yesterday and noticed as soon as steamer started working the plaster in question became dark immediately. I assume this confirms condensation as the issue

The room has 3 external walls all cavity but no insulation. The room below is an integral garage which we are converting soon so insulation will be added between the joists

I have left the old chimney uncovered.

I will wait and see if this improves as now the wallpaper has been removed I can monitor it.

Also, another quick question. I have an original welsh slate roof with no felt (approx 150 years old) in the other part of the house. I noticed on one of the disused chimney breasts in the loft there is a lot of salt visible on the brickwork. Almost covering a whole face of it. Do I need to treat this or as it's not affecting anything should I just keep an eye on it?

Thank again.
J