You do realize that you are asking how to stop water from running downhill?

You need to divert the water to the side before it ever reaches your skirting. A small dam, if you would, curving around the uphill side of the house. Ideally, your concrete pad, if you had one, would be raised a couple inches above ground level to prevent that from happening.

First sentence - very good point. I was thinking if there were a barrier behind the skirting water couldn't run under. The skirting sits on dirt. Thank you for your answer.

Also, nice forum.

The water would just eventually go under whatever barrier you put behind the skirting. Landscaping in a semi-buried wall of wood or stone or concrete, with a flower bed in it, could solve your problem.

Thanks again. May look into putting stone outside