| 摘要 |
Protective sheet, in particular for a foundation wall or a floor on the ground, said sheet (1) being made of a relatively stiff plastics material. A large number of spaced knobs (2) protrude from one side (1A) of the sheet, whereby the other side (1B) obtains a corresponding number of recesses (2A). The knobs (2) have a centrally disposed crater-like portion (3), the narrowest end (3A) of which is flush with the other side (1B) of the sheet. Between adjacent recesses (2A) there is arranged an open channel (4) provided through forming such that on the said one side of the sheet there appears a corresponding ridge between the knobs. Externally of the other side of the sheet there may be arranged a filtrating canvas co-acting with said channels (4). |
