I need to know if you use a different mix when cement rendering fibro or blueboard? I want to clad around the underneath of my deck and want a 'continuous' look from where the wall stops which means cement render (Block walls with a thick render).
Which is better Blueboard or Fibro?
What prep work needs to be done? I've seen fibro hold a thick render when chicken wire was attached to it. Is that the way to go?
Most of the 'just add water' render mixes state 'not for use on fibre cement so I guess there has to be a different mix?
i did my brickie's training yonks ago well before blueboard but when we rendered the old AC sheet we'd use chicken wire. nowadays blueboard has more absorbent qualities and doesn't "harden" and become brittle the way AC sheet did. i have rendered blueboard a few times and use a 6:1 mix with white washed sand and white cement (and add oxides for colour). to lengthen it i use bondcrete and a handful of Omo washing powder to a wheelbarrow load. the bondcrete gives bite when the mud goes off and the Omo (full of borax) keeps the mud smooth and "penetrating" when it is trowelled. there are commercial lengtheners out there but i just default to old ways. haven't seen a crack in nearly twenty years on the wall of the shed near the garden and i'm about to do a new addition the same way. and no chicken wire. use a good wide open mesh tape for the joins. i'm sure there are other techniques out there, too. goose and gander.
Fibre Cement or Blueboard render 
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