Leaking Garage

[andyr30]

I have a garage that is part of a block.

Everytime it rains the floor of the garage gets soaked...There's no obvious signs of where the water is coming in, however due to lots of heavy work benches etc I've not managed to have a proper inspection (it's definitley not the roof as that has just been replaced.)

The rear wall backs onto a neighbours garden. The garden looks to come quite high up the wall and also a row of conifer trees stops at the wall.

I am guessing this is probably run off from the garden seeping through the wall into my garage?

What's the best way of dealing with this?

Can I just use some sort of sealant painted onto the brickwork inside the garage?

Thanks