How to remove & remedy a failed chemical DPC v2

[theprinceofdarkness]

Good drawing cAtLeYx, I am hoping that there is a cavity between the two walls that could be cleaned out.
Frank

 

[cAtLeYx]

(in the 'understair' picture above, you can see the wooden frame to some shelves built into the party wall which used to be a window to the outside).

Could this be removed to inpect the structure behind / reveals etc?

 

[drpepe]

Good drawing cAtLeYx, I am hoping that there is a cavity between the two walls that could be cleaned out.
Frank

If I am to investigate this - would you suggest removing a brick or 2 from the wall under the floorboards?

Could this be removed to inpect the structure behind / reveals etc?

Good idea. I will broach this with the wife - she might be resistant to yet more destructive investigation!

 

[drpepe]

What I find odd is this picture:

I find it odd as it would indicate to me that your DPC is working as the wall only gets damp from 1.2m upwards...so seeing that I would be wondering if water is coming down the wall then being stopped by your DPC? Is it a continuous damp or does it get noticeably worse in wet weather or any other time?

If you have an old style boiler with a gravity fed system with header tanks etc. up in the loft it may be worth checking that none of the ballcocks are continuously slow'drip filling their tank - if they are it could indicate a pinhole leak in your pipework?? (although why it would go near what was your external wall is another matter but having a house of the same age I wouldn't discount anything without checking it!)

Hi - interesting comments, and definitely another avenue to investigate.

No water tanks up in the loft - we have a combi. The staining does seem to vary over time, but i don;t think it gets noticeably worse during rainy periods (this week for example).

Given that the damp appears along the whole length of the party wall (front to back), i thought it would be worth considering how next door's roof is detailed (see pic below). ANy thoughts on this - does it appear to be sufficient to stop water travelling down the party wall or cavity (if it exists?)

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