Warm air vapour condenses on cold lintel

[earnshaw]

Please see diagram below:

This is basically what is happening in my house - I have a brick lintel which is both inside and outside the house - so it is exposed to the cold air outside and when you touch the brick inside the house it is also freezing.

The annoying thing is - whenever it is warmer in the kitchen - or you cook something, the vapour in the air condenses straight away on this lintel because it is so cold - and it gets really wet - even dripping, this is staining the paintwork around it and making an unsightly mess.

Bear in mind this is Yorkstone - very old house - what is the best way to stop water condensing on the lintel? Are the some repelling treatments available? Should I insulate it with polystyrene - and plasterboard - and box it in and plaster over it? Or will I still get problems? Any experts out there who can help - reallly, really, really appreciated - as I have no idea what I can do to stop it!

 

[regsmyth]

Nice picture!
If you don't mind covering it up, then this would be the best thing to do.
It will always be cold if it's cold outside. As you correctly point out, it's only a problem when there's moist air next to it, so stop the moist air getting to it.
The best solution will depend on what would look best in the situation, but fundamentally, you would apply an insulating and damp proof layer, then plasterboard. Problem sorted.
Rigid PU foam, polystyrene, or even just an air gap would suffice. Just make sure you stop the damp in the room getting through by using foil backed plasterboard, polythene, or the foil side of rigid foam.
An alternative would be to ensure a good (forced) air flow around the lintel to keep it dry, but this might not be too easy.
Or if you want to keep it visible, box it in with clear acrylic. (I think this would be a stupid idea - but I can't help myself).

 

[Alastairreid]

or install a trickle vent on your window if you dont already have one.