Damp under bedroom bay window

[rushdentillidie]

We recently purchased a 1950's ex-council house. Before we moved into the house we painted and touched up all the rooms. Until we are able to save some money to tackle the big jobs (new windows and doors all around ect)

Over the last month or so i have started to noticed damp in the upstairs bedroom, under the bay window. I have attached some photos to try and show the issue. Looking at the double glazed window this will require replacing in time (mist in-between panes), but I am not able to see any obvious leaks from out. This is the only room in the house that we have any damp issues.

Given the damp patches and the black module forming on the window frames, i am thinking that this could be due to condensation. But we try to leave the window open during the day and have the heating on at night. We have even an aero 360 (small humidifier) but with little effect.

Does anyone have any ideas as to what this might be or how to rectify the problem in the medium term, until we can have the windows replaced.

Thanks

 

[ree]

Yes, you have condensation issues - three sorts:

1. condensation is forming on the cold frames and glazing and attracting mould.

2. pools of condensation (from 1.) moisture are forming on the cill and penetrating thro the mitres to enter the plaster just below the cill, and there show as damp.

3. room condensation is forming against the cold bay wall/partition.

Research on here about condensation in general, & on bay windows - there's lots of suggested remedies, & explanations of bay construction.

Note: the head/soffit trim (just below the bottom tile course) of the lower frames appear to be sagging with dark patches of something irregular showing.

 

[DIYedboy]

Condensation is your problem.............you must not use a humidifier, a DEhumidifier will help a little, keep the bathroom door closed when showering/ in bath then open bathroom window or fit an extractor fan to get the wet air out. If those windows are UPVC double glazed replacing them will be a waste of time.
Your wall beneath the window is single skin brickwork therefore it'll get very cold and attract all the water in the air. To cure this you'll need to install thermal plasterboard

 

[theprinceofdarkness]

I think the round area in pic 6 is penetrating damp. I suspect that the tile hung area has not got enough insulation. The penetrating damp could be from under the outside window sill. Have a detailed look at the top of the lead and window sill joint, it might need a squirt of silicone in here. Or it could be that the drip groove is missing or blocked up with paint and dead flies.
Could be worth investigating the insulation within the "roof" part of the bay.
Frank