Damp Garage

[aeyres]

I have a problem of seeping water coming into my garage around the line of my DPC along 1 wall.
I've figured this is mainly due to my neighbour having built the base slab of his garage approx. 1 foot above mine, and any water collects in the gap between the garages, fills up, and seeps into my garage. Main problem is, the gap between the garages is about 6-7 inches & is impossible to squeeze between to remove all the accumulated soil & debris (now above my DPC).
I have an idea to remove a course of brick from my garage, above the line of neighbours slab & introduce a DPC at this level, whilst at the same time lining the gully area with a plastic sheet & infilling it with concrete upto his slab level along the length of the garage wall. Essentially creating a 'higher' level DPC. Is this likely to work or will i still have seepage below the concrete infill??

Any alternative suggestions would also be appreciated as it is becoming a big problem.

[stoneyboy]

aeyres,
You need to stop rainwater getting into the gap between the garages see if one of the roofs can be extended to close the gap.
end