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After diggers have cleared out the rock around my back wall, I can see that in some spots the foundation appears to have gaps underneath. I assume if I kept digging it would eventually hit rock again.

The plan is to put recycled tarmac around the back as a foundation for a patio, and perhaps French drainage around the edge after the roof is done.

I'm curious if anything else, like concrete, should be poured under the foundation where these gaps are, or all the way around the edge to protect against water ingress into the gaps? Or is there anything else I should know about before doing further work?

foundation of stone wall

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SingularityFuture
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1 Answers1

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It is more likely that the act of digging has dislodged the dirt from under the foundations. You should fill it in with concrete or gravel/scoria. And then ram it tight. Not for the water, but to support the foundation.

Rohit Gupta
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