Waterproofing Block Built Wall

[Skavenger]

Hi,

I have built a workshop in my garden, concrete block base with a timber framed upper. The structure is built up against an existing block built garden wall. Before building my workshop I repaired this existing wall on the inside (my side) but have not done any work on the opposite side.

The wall is the weather facing wall and is letting damp through. Initially I thought the water was coming in were it was seeping in between the wall plate and the wall but after covering this up with plastic it continued so I can only assume that the driving water is simply seeping through the wall.

What would the best course of action be to waterproof this wall after of course fixing all defects / pointing.

1. Should I render the wall with sharp sand / cement and plasticiser?
2. Do I need to paint the render to waterproof it further?

Here is the wall in question from the inside, the dark patches are damp.

Thanks for your advice

 

[cjf82]

I would use tanking slurry. Been looking into this recently myself. Used tanking slurry on concrete floor and a brick wall - cured the issue. Cheap too.

 

[Skavenger]

I would use tanking slurry. Been looking into this recently myself. Used tanking slurry on concrete floor and a brick wall - cured the issue. Cheap too.

On the outside or inside?

 

[cjf82]

On the inside. The slurry on the wall took a while to dry - about a week to completely dry. The floor was faster, a few days.
In a perfect world I'd have taken up the floor and installed new dpm as it had blown in places and the wall - I'd have stopped the water at source but that involves neighbors and their higher ground level and their water butts overfilling since they decided to catch all the water from their roof in it. The slurry is doing well though!