Originally Posted by
Slab Junkie
You don't have to put any screws or nails through the PVC to get the concrete to hold. Just rough the pipe up with 60 grit sand paper and push down into the concrete and leave it to dry for a few days. Once dry you will not pull the PVC out of the concrete. Don't get too anxious about getting the concrete out of the forms it needs to set for a few days. The moisture has nowhere to go since it's in a plastic tub so it needs longer to cure. You probably don't have to, but coating the plastic tub with non-stick cooking spray before adding the concrete works as a great release agent.