Redering over waterproof slurry


New Member
I have applied water proof slurry to a large patch of exposed brick on a basement wall. I now need to render and top coat. Can I add some of the slurry (Sika) to the render mix (sand and cement) to add to its waterproof quality and do I need to damp the dried out slurry surface before applying the render?
I would not use waterproofer on wall, it slows down the setting time forever and a day, dump it, plastering sand, cement, hydrated lime, 6.1.1.