Damp spots on interior wall

[elchanco]

Hi,

We have a problem with damp spots on the gable end of our house. recently, we decided to have the hall/landing painted & noticed how bad the damp spots are.

I was advised they could be condensation spots? The damp spots start half way up the wall, parallel with upstairs & are spread across the upstairs wall.

We have a drain pipe running across the exterior of the wall. I pur in this pipe because two houses were sharing the same down pipe & the gutters frequently over flowed.

What can be causing these damp spots? I cant see any wall vents along the side of the house (condensation).

Any help appreciated

[andertonj]

Hi Elchanco, I would like to tell you that damping in roof arises due to low water resistant capability of roof and existing walls. Damped condition for a prolonged period affects the overall sustainability of your roof and paint quoted on roof will break into pieces and will gradually fall on the floor. what I think now after reading your post that these condensation problem could be due to water tank on your roof as I guess you are living in a apartment where two flats share a common guttering pipe (as you told in your post that you and other house have shared guttering pipe) and in apartments you will find water tank installed on the roof surface most probably which should not be there actually. It should be installed ideally at a fair high position from the roof's surface.