To provide a waste coating capping sheet reduced in a variation of a water intrusion amount even if a laying condition such as a rainfall amount and a slope gradient is varied, and to provide the capping sheet by which a water permeation amount suitable for a site can easily be obtained by changing its front and rear surfaces.
A waste coating water-permeable capping sheet has a laminated structure of at least two layers composed of a first fiber sheet and a porous sheet. The capping sheet is the waste coating capping sheet whose unit weight is 80 to 1,200 g/m2, in which respective water permeation factors of both faces of the capping sheet measured by a JIS A1218 (1998) 5 method (constant water level water permeation test) are 1×10-7 to 1×10-3cm/s, respectively, and a value at the face higher in water permeation factor out of both the respective faces of the capping sheet is larger than a value at the face lower in water permeation factor by 50% or more.
KOIDA TAKASHI
Hisahiko Ueki
Tadashi Sugakawa
Hiroaki Ito