I have recently broke up my old concrete shed base which was 100mm thick, I also have quite a lot of gravel. The broke up shed base is quite large chunks of concrete so could I use that a long with the gravel as a sub base for the new concrete base I am about to lay? The chunks are a range of sizes from 20mm to about 90mm. Would it be ok for me to whack it down? Or should I just buy some proper stuff. The new base is for our new summerhouse.
Thanks for looking.