Will this require underlayment and vapor barrier?

Hi Coachman and thank you for your inquiry. The Style Selections Penny Oak Luxury Vinyl Plank does not require additional Underlayment as it already has an attached underlayment on the back. We do not require a vapor Barrier if you are installing on a wooden substrate but would recommend a vapor Barrier if you are installing on a concrete substrate. Again we thank you for your inquiry and hope this helps answer your question.