What is the difference between QA and QC in construction?

Quality assurance is the planned system that prevents problems: the quality plan, material approvals and the inspection schedule. Quality control is checking the actual work against the drawings and specifications, which is where checklists, inspection requests and test reports come in.

When should a quality control checklist be completed?

Complete it at each hold point, before the work is covered up or the next trade starts. Typical examples are before a concrete pour, before drywall closes a wall and before flooring goes down. The project specifications usually list the required inspections and tests.

Can I adapt the checklists to my project specification?

Yes, that is the intent. Edit the items to match your drawings, specifications and manufacturer instructions, and add the acceptance criteria your project requires. Each product page lists its file type so you can check it before downloading.

How should work that fails inspection be handled?

Record it on a non-conformance report with the location, a description and photos, agree the corrective action, then re-inspect and close it out. Keeping a log of open items makes it far easier to clear deficiencies before handover.