Water ingress

[pateli]

Hi from a newbie in Ireland. My problem is with a concrete shed which was built several years ago,
It is built with 4 inch solid blocks. 3 sides on my property was plastered the side in my neighbours garden is not and during heavy rain I get a mini flood in the shed this only started in last few months. I coated the wall with Black Aqua sealer but no good.I then put more sealer on wall and covered it with plastic and more sealer but the water is still getting in. I would appreciate any suggestions as to what I should do next, Should I ask my Neighbour to let me have wall plastered on his property.

[HayZee518]

not too clear on what you mean

your shed I guess is built on a slab. if the floor was poured concrete, was there a provision to provide a "key" for anything going on top of the slab? by a key , an angled 2x4 stud is pressed into the wet concrete until the concrete cures, then the 2x4 is pulled out leaving a V notched recess. A future pour or concrete blocks are [is] installed with mortar in this V groove to make a water tight seal. if I'm getting you correctly, you have a block constructed shed. the joints should have a slow cure mortar joint either placed directly or "back-buttered" one on top of each other. a better sealer like "THOROSEAL" is a portland cement product will make the surface water proof. If you wish more sealer then an asphalt based sealer can be sprayed or brushed onto the surface.