MrSlope
wibbled on Sunday 25 April 2010 08:31

Hello -

My house is built on higher ground than my neighbour's. There's currently
a 1 metre height difference between my garden and my neighbours, retained
only by a wooden fence which is beginning to fail. It looks something like
this: http://i40.tinypic.com/4rqb11.png

I'd like to avoid the cost, possible damage to trees, and disruption of
having a block retaining wall built, and a structural engineer has
suggested excavating the part of my garden next to the fence, to restore
something similar to the original slope, and then putting in decking over
the resulting sloping ground.

Does this sound like a good idea?
What sort of slope angle might the engineer suggest, given that the soil
is clay (this will determine the area of decking) ?

45 degrees. I have slopes like that in my garden on clay. I've got a bank at
about 2' high with a slope of about 30 degrees off vertical that is stable,
so you can get away with more.

Is this likely to be cheaper than a block retaining wall, given that less
excavation is required?
What might the cost of the decking per square metre be?
Would planning permission be required?

Check the "planning portal" but I doubt it as your decking would not be
above the original ground level - but you should read it yourself.

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.