After around 18 months of planning things have finally been moving a lot faster over the last couple of weeks which is great!  I'll try to summarise the interesting bits:   Type 2 vs. Type 3 Our EPS was installed on a sub-base of 150mm MOT Type 2 and 50mm sharp sand for blinding.  Structurally this is absolutely fine, but there was an awful lot of and fro with the foundation designers about if permeable type 3 + grit should actually have been used as specified in the system certif