RJH wrote:

I need to break up about 5m x 5m of concrete, varies in depth, seems to
be about 4" max.

I intend to do it over a few weeks, once the weather improves. Would
this be up to the job:

https://www.aldi.co.uk/workzone-demo...96542269374000

I intend to buy it, then sell on ebay once it's done.

I got a very similar but slightly cheaper one on Ebay (?75GBP) and it
did a similar job without struggling. If the concrete is wholly
bounded by walls with no free edge and you have a big angle grinder it
migfht be worth cutting a coupl of parallel slots about 200mm apart and
im long just to get an edge to start with, concrete being much easier to
break if not in compression. Otherwise best to drill a hole with a big
masonry drill or the pointed breaker. Once you have a edge the
chiselling away 2-4" chunks seems to work best. Won't take more than a
few days, depending how far you have to move the bits.

--

Roger Hayter