Damp internal wall

My garage has two internal brick walls and the bricks suck up rain constantly during winter, then on days it clears up the entirety of the brick is soaked which has been a huge issue for the last few years of living here. It seems like the landlord has applied a sealer (the beige colour on the outside of the brick wall shown slide 2) but it’s a very thin layer and obviously not very effective. Boxes and any furniture stored grows mould even when kept away from the walls because of the moisture in the air, a dehumidifier works (sort of) but is expensive. Essentially I’m after a sealer to just fix the problem but what can I do if I can’t get down the side of the house because the gap is far too small? An extended paint roller could barely fit…Any suggestions hugely appreciated!!