I saw Diz Disley perform this song several times, in pubs around Amersham and High Wycombe. This would be 1970/71. The only lines I remember specifically are:

   Half a ton of broken bricks
   Buy a load of Readymix (* a well-known brand in those days)
   Pour it and watch it har - ar - den ...

What a man. Liked a pint, too.