The Turf Roof is a roof you can build (the Hearth kit).
In-game description
Grass turf laid on the boards, a log along the eave, a stone chimney on one corner. In the tundra the snow lies deep on it.SHOWN IN THE BUILD RING
Building it
It costs 2 
Cotton Grass, 2 Any Grass, 1 Water spirit. Take it down with DISMANTLE to get its cost back (see Building).
