Lateral damp problem

[bottle top]

I live in a mid terrace victorian property built around 1890.

The rear yard is enclosed with brick walls approx. 6ft high that join onto the rear of the house.

Where the walls join onto the rear of the house I have damp patches on the internal walls that run inline with the garden wall.

The damp is not rising from the floor and is not coming from above. There is no gutters,CH pipes, vents, etc close enough to be causing this damp.

I have been advised by a reputable damp company that the problem is caused by damp from the garden walls being drawn into the house and the amount of damp in the house will fluctuate depending on the weather.

This Iam told is a not an unusual situation for this type of house.

His advice was to remove the plaster back to the brick on the internal wall with the damp patch from skirting board to picture rail. Then coat wall with Sika slurry and ensure the first coat of mortar has a damp repellent in it.



My impression is the damp will still come in to the house but remain in the brick and not spoil paintwork.

I have two questions: Firstly is this approach to hide damp problem normal and what can I do to external garden walls to stop damp coming into house.

I have hopefully attached two photographs.

Cheers for looking.

 

[Wilco79]

I have the exact same problem in my 1907 mid terraced house. Lived there for 10 years without any problems. Damp started in the last 12 months but being temporarily out of work until recently meant I could not treat the problem sooner than I had liked.

The damp starts at the exact height of the external wall and tapers down getting wider to about 10ft into the room just as Bottle Tops images show.

My neighbour who shares this wall with me has no problems at all?

I have re pointed the brickwork on the external wall (both sides) the mortar had basically turned to soil it had perrished so badly (neighbours husband build the wall about 15 years ago) I have also added coping stones to the top of the wall.
But when it rains the internal damp gets darker and wetter to the touch.

The back of the house does not have a damp proof course so I am planning to use DryZone and do this myself. I don't know weather it is worth running this vertically drilling diagonally into the corner where the wall meets the house?

Hopefully once this is done I plan to remove the damp plaster and run a dehumidifier to dry out walls before re plastering.

I am interested to hear how the experts/others think myself and Bottle Top should handle this problem?

 

[gregers]

if the walls are cavity then i would say there either blocked or been bridged somewhere,hence the lateral damp.
open up cavities and clear out all/any crud.
if its solid then a vertical dpc needs to be injected.well thats what the damp firms will recommend and replastering.