I'm planning to build a deck on sloping ground, and want to create concrete foundations which raise up above ground level. In order to do this, I think I need something called a former - a thick cardboard (or something) tube or box which I set into the ground and pour my concrete into. The cardboard (or something) has to be thick and dense enough, not to go soggy I presume???
Can anyone help me source these formers? I have looked in most of the local DIY shops and have drawn a blank! I think what I need is a tube or box former of around 8 inches in diameter.