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Moisture build up in corner of outer walls - help

Posted by Kay Percival, on
I have two outer walls that corner in the main bedroom of my first floor flat. The corner gets extremely cold in the winter and due to a build up of condensation in the room can lead to mould. I've treated it with anti-mould spray prior to painting and I have damp traps and dehumidify on a regular basis. Both outer walls are brick and have no current cavity wall insulation as the gap between is too small. Is there anything I can do?
Michael Tucker

Michael Tucker

Hello Kay, I'm guessing you don't have much air flow, I would recommend trickle vents to the windows or an air brick to the wall Regards Michael
Chris Plastow

Chris Plastow

It is a problem with corners, they build up condensation and they are colder than mid sections of walls. Black spot mould will only grow if the relative humidity is above 65% , so each time the mould grows , its because of the low temperature in that wall corner. Look on google for a fan, HRV150-12 hour, this is what you need. alternatively you can glue some polystyrene board to the wall to insulate it . lastly google a company , Minster, look for a 50mm insulated plasterboard and get a contractor to fit it .
Paul Collins

Paul Collins

Obviously check for outside problems like gutters etc. Other than that, lack of ventilation is the problem almost certainly, all that moisture produced by cooking, breathing etc. has to escape or black mould will result. Air bricks, vents, opening the trickle vents will all help.
Andrew Smith

Andrew Smith

Hi Kay, firstly . check you don't have a leaking pipe or gutter problem that is making the brickwork wet, if so as it is solid brick construction in time the water will penetrate through. If not then i would clean the mould with a bleach solution and hang a polystyrene type wallpaper about 5mm thick and hung like wallpaper to the walls. This wiill insulate the walls and create a barrier for the mould. You can then hang lining paper over the top and decorate to you taste. A.L.SMITH DECORATING SERVICES, Est 1980
Louis De Courcey

Louis De Courcey

Ventilate the room with a air vent system , check no moisture is getting through the brickwork , and then you could possibly put some insulation up against these walls within a stud wall . Hope that helps

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