Footings for conservatory - on solid rock?

[dave-g]

I am considering building a conservatory (which will not require building regs) To reach floor level, it would need a 2 foot wall building at the highest point, to 6 inches where it meets the external house wall. (stone on rock) This would then be topped with a 2 foot dwarf wall.

The proposed area is completely made up from an outcrop of solid rock. I have read on the footings projects page of this site that the footings should be as wide as the wall, but that the LA control the depth. As this project does not come under building control, I do not want to bother them!

so, to the question... do I have to excavate a trench into this rock, or, can I get away with disc cutting/jack hammering a roughly flat surface, and then building a stone faced, block wall on top of this?

thoughts?
Dave

[stoneyboy]

dave-g,
If the rock surface is sound build straight onto it.
end