hello chaps got to price a Gable up .it s a old place with ashlar which is covered up badly with high build which is blowing . i want to hack off and stat again . he s had a few course s of bricks replaced and the old bricks that are exposed are poor . he want s to get high build off and if existing render is sound I'm thinking rendaid followed by thin coat or through coloured textured . I'm a bit worried about the latter failing ,or should i just go for it maybe key it with a grinder before rendaid . can thincoat go over rendaid thinking of trying sas stuff or do Weber do one or is there a better one to use?