Some good answers here. Freeflo or anything of the kind does not belong in lime render. By lime render I mean lime based- nhl or putty. In both cases will stop the lime curing and will be total failure. The lime in this mixes won’t have contact with the water nor the air , which you can thank the plasticiser for. In sand / cement /lime mix it’s role is completely different because the amount of lime is compensated by the amount of cement. Every job has to be assessed before you make your decision. Not while ago I had to render over painted surface with s&c . Had to do harl coat with sbr first and used sbr in the mix too. I usually always use lime in the mix instead of any other additives . I think my mix is good , just like everyone on here thinks there is nothing wrong with his mix and that’s based on how we have been thought and shown. Since that time thinks have evolved, bagged render has become more reliable and better than ever and that’s because manufacturers have developing teams to move the companies forward.
So in short, I really doubt plasticiser can do any harm in this case, it will however reduce the lime effect in the mix , not the other way as was suggested before.
