Step 9 — Complete the EcoShell II with a 3/4" minimum cover over the rebar on the outside and 1/2" to 3/4" cover on the inside. EcoShell II should have a coating placed over its exterior surface. If the EcoShell II’s exterior is not coated, it’s considered unprotected concrete. Technically, there should be a concrete cover 2" over the rebar.