Damp external wall on the inside

[dulciepreston]

Hi,
I have a damp first floor external bedroom wall which is showing signs of damp on the inside. This is a gable end and very exposed to the elements and my question is, is it likely to be penetrating damp or condensation? There is a large double galazed window in this wall and a ventilation brick in the lower corner and the damp appears in localised patches around the window. The wall is sand cement rendered on the outside and painted with weathershield. There is no evidence of water getting into the structure around the window.

Any assistance will be most appreciated.

 

[dishman]

Read the recent posts re:damp there are many

Ask yourself:

Do you have extractor fans in the kitchen/bathroom
Do you dry clothes on radiators or in a Vented (not condensing) dryer
How do you heat the house currently
What insulation does your house have

If it is appearing mostly in winter and depending on your answers to the above. It is very likley to be internally generated damp.

 

[nebjamin]

We have had a similar problem due to cracked render on the outside. In our case it's very obvious that it's come from the outside because it's made big yellow stains on the wall from all the crud it's seeped through.