Sanded panels are not pre-primed. Calcium silicate boards must be primed before processing. If you would like to save yourself a work step, choose our pre-primed boards. These can usually be glued on directly as long as your substrate is not freshly plastered or highly absorbent for other reasons. Highly absorbent or freshly plastered substrates should be treated with a silicate primer beforehand. If you are unsure, you can also prime the substrate as a preventative measure without hesitation.
