Sika-Trocal®/Sikaplan® Type S-Vap 500E Vapour Control Layer provides an effective solution for applications below humidity class 4. Where a higher performance is required, such as swimming pools and green roofs, suitable solutions should be sourced from 3rd party suppliers. Where a bitumen based solution is chosen this must not come into contact with the Sika-Trocal®/Sikaplan® membrane.