Hi, I was planting a couple of things in my garden and discovered a large piece of cement. I have managed to expose the majority of it, but I wanted someone's opinion on whether it would be safe to remove? My gut feel is that this was probably where the builders were mixing their cement, but apparently sometimes builders would pour concrete over pipes to protect them if they were close to the surface? This is about 1.5m away from the house. The concrete has various heights, ranging 5 to 15cm underneath the soil level. It also varies in thickness and width. Any recommendations to remove it would also be appreciated, I am thinking of using a hammer and chisel and break it off piece by piece (will obviously take a while) but that way I can at least see if I am going to damage something. Thanks!!
To be sure what is under the concrete you'd want to check plans which show stormwater and sewage lines. Plans would have been submitted to your local council when the build went ahead, and you should be able to acquire them.
I'd expect to see a slightly more uniform concrete encasement of the lines if it was one. This isn't necessarily a sign that it is not, though. You could keep following it along, and if it is just a chunk of concrete, it will stop at some point.
Once you are confident that there are no pipes underneath, then you could use a demolition hammer which would make quick work of the job. If you continue with a manual chisel, you'd want to swap that rubber mallet out for a Craftright 1.8kg Stoning Hammer. The rubber mallet absorbs too much of the stroke energy and will make it difficult to chip away the concrete.
Please let me know if you need further help or had questions.
Or try a fencing crowbar using a brick or lump of wood as a fulcrum, and see if you can lift the slab.
This is so annoying hey.... builders do like to hide stuff when finishing up. Looks a lot like what you said. Cleanup area from cement mixer. Them lil buggers.
Hope it came out ok.
Have you made any progress on removing your large piece of concrete? I'm interested to hear how you went and what it ended up being.