Damp Proofing

Wall in between 2 pitched roof garages causing damp inside garage

Anonymous user 01/03/2024 - 2.51 PM

Hi, I have searched for an answer to this but could not find one so here goes. I recently bought a house built in 2004 with detached garage so just over 10 years old, the neighbours house and garage was built more recently about 5 years ago. There is a brick wall next to my garage which is now sandwiched between the 2 garages so 3 walls in total. The neighbours garage has some sort of membrane coming out about a few inches above the wall, down and part way onto the brick wall in the middle and any water that gets on the wall is penetrating the masonry on my side. Inside the garage the walls can feel wet, are darker in colour and efflorescence is coming out. This starts about 3 ft off the ground as it is dry from the floor, and continues to the line where the top of the wall is. What are my options? I am looking for a long term fix so will I need to retrofit some sort of guttering to get the water away or apply cement, sand and waterproofing mix to where the walls meet and spray with water proofing? I haven't come across this before so the above are just ideas, any professional advice would be greatly appreciated. Thanks, Simon