I paid my contractor for a couple of progress payments and received a prelim lien from the supplier. The contractor has not paid either the sub or supplier. Do I need unconditional waiver and release on progress payments from both the sub and supplier or just the supplier? Also would I need to issue a conditional final payment release to just the supplier?
Your primary concern would be to resolve the possible claim from the supplier which is preserved by the supplier's service of the preliminary notice. But since a subcontractor (or any claimant) can still serve a preliminary notice and pursue a lien claim for all future labor and materials in addition to the labor and materials furnished in the 20 day period prior to serving the preliminary notice, ideally you would get an appropriate conditional waiver and release from both the subcontractor and supplier. I suggest consulting with an experienced construction attorney to make sure you get the right advice for your particular situation.
Likely, but you would need to refer to your contract with the contractor and consult with an experienced construction attorney about your specific situation. Every project is different!