To insulate our floor we decided to use 180 mm Isolena Sheep Wool. This was slightly larger then the height of our inner frame (155 mm) since we first planned on building our entire floor with a height of 175mm. But the insulation ended up fitting perfectly inside the structure since the sheep wool was very flexible. The sheep wool came in rolls with a width of 600mm. We decided to cut them crosswise into pieces of 400x600mm instead of cutting them lengthwise into long narrow pieces because we would otherwise end up with lots of small bits.
To do this we measured the length of one roll and marked this onto a wooden board. We then placed another mark every 400mm onto the board. Next we placed on roll evenly onto the board. This way we knew exactly where we had to cut the sheep wool. We started with a bread knife but ended up gently ripping the wool with our hands since this was more effective.