Is it possible to cut down a PCC IC section if it is enclosed in concrete per this diagram?
A recessed tray is to be installed but the crown is already level with the finished paving level, this would appear to be the easiest method to lower the chamber level prior to reseating the crown and adding a recessed tray. Unless anyone has prior experience that PCC won't cut nicely using a grinder.
Or from the inside with a small cutter, wash it down with disinfectant first, especially if foul I C. I never concrete around those plassy I C s, i back fill with decent as dug, shingle, or mot. The only concrete you should use is if taking vehicles and then only a 150 thick plinth. The top 150 should be wrapped to stop the concrete filling the fins so keeps the concrete separate from the I C, That will enable the cover to take the load off the chamber.
