Hi John,
Usually on a slope grade a foundation is roughly the depth of.....
level out 5 feet from the grade and measure the distance to the ground at 5
feet.
The footing should be this depth plus 18 inches.....
So if I leveled out from grade 5 feet and measured down to grade and had 2
feet I would build a footing that was 3 feet 6 inches deep.
This is rule of thumb and not necessarily engineered for your soil type.
A person could build a retaining wall out at a distance and backfill this to
support the existing faulty condition also.....
Good wishes.
jloomis
"John" wrote in message
. ..
Hi,

Our N.Z. timber house is on a slope. The side of the house facing the
valley has concrete foundations that are very, very shallow (probably no
more than 8-10 inches deep). My guess is that when it is raining very very
hard, and for a long time, the foundations can move a little bit. Another
issue is when kids are playing with the garden hose... (ouch!)

We've had to replace one foundation that was kind of going down the valley
actually.
Four other concrete foundations could be replaced.

The inside of the house is quite new, I'm scared that the repiling process
may damage the nice work that been done inside.
Is the repiling process safe? Is the house likely to move when repiling?

The house is on clay.

Any opinions?

Thanks for any advice.