Help - cause of damp?

[tompparker]

Hi,

My house, built c.1900, was treated for rising damp in 2010.

The downstairs bedroom now has damp appearing on the interior of the outside facing wall (which faces south west).

Please could you advise as to the cause of this damp (esp. zoom image 2)?

View media item 72392 View media item 72393

 

[Bodgeitandleggit]

pictures from the outside would help... is there a gutter broken /missing and water running down the wall?? it looks as though you have a cable coming through where the damp patch is.. is the brick damaged outside where the drilling was done.. ?? is the water running dwon the cable and hole no sealed..? is there something above the damp course?? pictures from outside would help

 

[Diyisfun]

Just had similar problems, I got the company back, they measured temp humidity etc & said it was condensation. Which I scrubbed off.
http://www.cleanipedia.co.uk/en/house-exterior2/how-to-remove-mould-and-mildew-from-walls

I have today just found some more, which is upstairs in an unused bedroom.
I have cleaned that off, now I cant make my mind up, as to turning the radiator in that room off, or leaving the door open.

(My house is circa 1800)

 

[dishman]

Read the many recent posts on damp. Eliminate yourself as the cause...however unlikely you think that to be, try to change you living habits first, however hard you may find it....as that is a free way to initially diagnose and possibly solve the problem.

http://www.diynot.com/forums/building/low-level-damp-patches-on-internal-walls.389770/

Read these:

http://www.bolton.gov.uk/sites/DocumentCentre/Documents/Condensation and Mould.pdf

http://www.scotland.gov.uk/Publications/2005/05/10103020/30217

 

[Diyisfun]

Just ordered a 55w t/static tubular heater, I will also put it on a timer to reduce running cost.

 

[jeds]

The black mould is due to condensation. First step is reduce water vapour; don't dry washing on radiators, make sure your tumble dryer is ventilated, remove excessive numbers of house plants, open trickle vents, use bath and kitchen fans and open windows occasionally. Second step is to increase temperature.

The patch near the cable - I wouldn't mind betting the cable runs down the wall externally and straight into the wall with no drip loop. Does it loop downwards and then back up into the wall? If not the cable is tracking water straight into the wall. So you need to alter the cable.

 

[Blagard]

You definitely need to follow Jeds and Dishman posts because you definitely have condensation.

As for your rising damp treatment - While a damp external wall will encourage condensation because it will usually be colder, in the vast majority of cases low level condensation is simply the result of the way we live. Because the cooler air in your room is more saturated with moisture and is low down, that is why condensation will often appear at skirting level on a wall that has no rising damp at all.

 

[Flyboytim]

Applying heat is a difficult task at skirting level. Heat rises by convection, away from near the floor where the problem is.

Better to use an ordinary unheated fan to direct air at ambient room temperature to the area where condensation is a problem. Once the skirting area reaches the same temperature as the rest of the room then it will not condense out there selectively.