Hi, getting porcelain patio laid. As 1:80 fall must be considered the patio ends 4cm below the lawn. What are my options for this problem? 1) The patio is starting 12cm below DPC. Can I start a bit higher (starting 8cm below DPC) and leave 5 or 10cm gap between wall & patio start and fill the gap with gravel. 2) Do I have to remove soil from the lawn to make it level with patio? 3) Are there any other options for this problem? Appreciate your help. Thanks.