Slabs can also be made of wood ( timber ) .
Slabs can also be need to be treated with preservatives , such as paint or linoleum , to prevent rotting and to enable thorough cleaning of the squatting slab .
Slabs can also be made of wood ( timber ) , but need to be treated with preservatives , such as paint or linoleum , to prevent rotting and to enable thorough cleaning of the squatting slab .