I recently built a new sloped shower subfloor using latex-fortified portland cement. I spritzed it with water while it was curing for the first 36 hours. I found on day 4 of curing that the cement has 4 cracks from the edge of the drain to the screed strips. Do I need to start over or can I fill the cracks with hydraulic cement? Everything I have read on pan replacement only allows 24 hours before starting on the pan liner and curb. Are these cracks common?