Damp in new garage walls

[fredster]

Hi there, I hope someone can give me some advice about our garage.
We had the garage built last summer with the rear wall and one side wall covered almost their whole height with earth (the lawn). The walls are made of single layer breezeblock filled with concrete, with a plastic sheet covering the outer wall up to to the level of the lawn. A layer of clay "pebbles" was also used adjacent to the walls to aid drainage.
Fairly large patches of damp are now appearing inside on the walls mainly towards the corner of the walls.
I am not really concerned about it if it is to be expected, in which case i can get DIYing with some paint on remedy.
The question is, is it to be expected when the wall was built by a professional builder? Will it affect the structural integrity of the wall or will it just cause the contents of the garage to get damp?
Any thoughts would be very welcome.

 

[Burnerman]

For a semi underground garage, the tanking has to be properly and completely done without any short cuts.
I would have expected the new wall to be completely coated in bitumen first, followed by an unbroken layer of vapour barrier such as a Visqueen which should be fully stuck to the wall.
Another layer of bitumen is applied, followed by another plastic membrane that is 'pocked' - i.e it doesn't fully contact the wall. (Sorry its name escapes me - it was years ago when I did this.)
If possible, drainage chippings should be laid at the base of the wall and lead to a water course (I know this isn't always possible).
I assume that the garage floor had a vapour barrier in, and the blockwork had a DPC too.
Anyway - your tanking isn't good enough, unfortunately. The wall is unlikely to be damaged but salts will soak through. The garage humidity level will be high.
Can you thoroughly ventilate this structure to help things?
As you may have gathered, I know nowt about the building regs that may apply to this - but the theory's there anyway!
Just my opinion, naturally.
John

 

[fredster]

A seems short cuts were taken when the walls were put up! It isn't a disaster so long as the wall doesn't get damaged by the damp. I could try some at damp treatment on the inside of the wall, which may help (and leave the door open!)

 

[foxhole]

No paint on damp remedy is of any use.