Question about blue grit … have already preped block wall with blue grit ready to skim. But will now use lime to match in with other walls. Will the lime render be OK on the blue grit? Any other prep recommended? I will be using Cornerstone Dry Mix CLD30 NHL 2 (9mm) with 2 coats of lime putty to finish (2 x 1.5mm). Blue grit specifies 12mm max total plaster thickness.