=== UPDATE ===
I wanted to provide a quick update on this project so others coming upon this thread can make some use of my experience.
The project breaking and removal is almost complete and on the whole it turned out quite well.
To begin the project I took out the paving slabs that covered the area. I did this using a wrecking bar, a rotary hammer drill in chisel mode and lots of patience. Taking off all the paving slabs from a 20-25 meter square area took me 4 hours. I was taking it slow and easy since this is the first time I have done something like this and I was also enjoying the use of my first ever SDS drill. I suspect that next time I do something like this it will be much faster.
Beneath the layer of paving slabs was a 2-3 cm thick layer of screed. I did not take this out thinking that it would anyway come out when the concrete was broken. In retrospect I should have spent a few hours taking this layer off with a long prying bar. This layer seriously messes up visibility when breaking concrete so if I had to do it all over again I would spend some time taking this layer off so that the top of the concrete was exposed and relatively clean. The trick to breaking concrete is doing it in the rightsized chunks depending on the power of the tool and the thickness and strength of the concrete. To this efficiently it is important to be able to see the concrete while using the tool without it being obstructed by dirt or soil.
I hired a Hilti TE 3000-AVR concrete breaker (and a transformer) from HSS hire. This tool is electricity-powered so there is no need for a compressor. It weighs 30 kg so I did not have to put much downwards force while breaking the concrete, I only had to hold it stable. It also has handles that move up and down like shock absorbers so that very little of the vibration is transferred to the arms, shoulders or torso. I highly recommend this breaker for its simplicity, power and ease of use.
I discovered that what I thought was a single layer of 10 cm concrete was in reality 2 layers of about 5 cm each. Over the years the occupants of the house kept on adding to the layers without taking the previous layer out.
Breaking the concrete was very easy. The breaker would do its job in 2 seconds when placed on a specific spot. I got tired not from the vibration itself but from having to lift the heavy tool a few cm every few seconds. After breaking about a meter square or so I figured out the correct distance from the edge for placing the breaker chisel. This ensured that large enough chunks broke off without the chisel bit getting stuck in the concrete (which happened exactly once when I started using the tool).
Breaking the concrete was very easy. It was collecting the broken rubble in flexi-tub buckets and taking them to the front of the house via the narrow hallway that proved to be time-consuming, tiring and frustrating. My partner helped me in carrying the rubble and we used Gorilla tubs, Faithful tubs from Amazon and B&Q cheap red tubs - all proved to be of good enough quality for this project.
If I had to do it again I would construct a small railways like contraption using MDF, think long pieces of wood (not sure what they are called but they are in the same area as joists in my local B&Q), castor wheels etc. from the rear to the front of the house on which the buckets could be placed and pulled along tracks.
If you have to do this project I recommend hiring a good breaker, figuring out an efficient way of disposing off the rubble and doing it yourself. It will take about 2 days, consume lots of calories but it will be quite satisfying and will also save a few hundred quid.
Feel free to ask questions and I will do my best to answer.
I wanted to provide a quick update on this project so others coming upon this thread can make some use of my experience.
The project breaking and removal is almost complete and on the whole it turned out quite well.
To begin the project I took out the paving slabs that covered the area. I did this using a wrecking bar, a rotary hammer drill in chisel mode and lots of patience. Taking off all the paving slabs from a 20-25 meter square area took me 4 hours. I was taking it slow and easy since this is the first time I have done something like this and I was also enjoying the use of my first ever SDS drill. I suspect that next time I do something like this it will be much faster.
Beneath the layer of paving slabs was a 2-3 cm thick layer of screed. I did not take this out thinking that it would anyway come out when the concrete was broken. In retrospect I should have spent a few hours taking this layer off with a long prying bar. This layer seriously messes up visibility when breaking concrete so if I had to do it all over again I would spend some time taking this layer off so that the top of the concrete was exposed and relatively clean. The trick to breaking concrete is doing it in the rightsized chunks depending on the power of the tool and the thickness and strength of the concrete. To this efficiently it is important to be able to see the concrete while using the tool without it being obstructed by dirt or soil.
I hired a Hilti TE 3000-AVR concrete breaker (and a transformer) from HSS hire. This tool is electricity-powered so there is no need for a compressor. It weighs 30 kg so I did not have to put much downwards force while breaking the concrete, I only had to hold it stable. It also has handles that move up and down like shock absorbers so that very little of the vibration is transferred to the arms, shoulders or torso. I highly recommend this breaker for its simplicity, power and ease of use.
I discovered that what I thought was a single layer of 10 cm concrete was in reality 2 layers of about 5 cm each. Over the years the occupants of the house kept on adding to the layers without taking the previous layer out.
Breaking the concrete was very easy. The breaker would do its job in 2 seconds when placed on a specific spot. I got tired not from the vibration itself but from having to lift the heavy tool a few cm every few seconds. After breaking about a meter square or so I figured out the correct distance from the edge for placing the breaker chisel. This ensured that large enough chunks broke off without the chisel bit getting stuck in the concrete (which happened exactly once when I started using the tool).
Breaking the concrete was very easy. It was collecting the broken rubble in flexi-tub buckets and taking them to the front of the house via the narrow hallway that proved to be time-consuming, tiring and frustrating. My partner helped me in carrying the rubble and we used Gorilla tubs, Faithful tubs from Amazon and B&Q cheap red tubs - all proved to be of good enough quality for this project.
If I had to do it again I would construct a small railways like contraption using MDF, think long pieces of wood (not sure what they are called but they are in the same area as joists in my local B&Q), castor wheels etc. from the rear to the front of the house on which the buckets could be placed and pulled along tracks.
If you have to do this project I recommend hiring a good breaker, figuring out an efficient way of disposing off the rubble and doing it yourself. It will take about 2 days, consume lots of calories but it will be quite satisfying and will also save a few hundred quid.
Feel free to ask questions and I will do my best to answer.
