I have a rather unfortunate problem, rats got into my crawlspace and managed to tunnel directly underneath one of the internal piers(there are quite a few down there, maybe every 8 ft square?
I am in the process of collapsing their tunnels but this will need to be fixed, the pier isn't very deep(maybe 6 inches in ground?).
How would you recommend fixing this issue?
If I could build a form around the pier and inject concrete into the tunnel I suspect this would be sufficient but I don't know. I don't know of any mini concrete pumps though.
Suggestions?
I should also say this is a 1 story house built in the 70s, pretty low load.
Best Answer
Don’t collapse the hole under the pier fill it with sand use water to flush the sand and pack it, I have found adding lime to the mix keeps them from tunneling.