Does it need underlayment?

Hello Leslie - thank you for your inquiry. The Style Selections Sisal Oak 4.4mm LVP comes with a pre-attached underlayment already. The use of additional underlayment is not required or recommended. If you're installing on top of a concrete slab subfloor or basement, then you would need to use a 6mil black polyethylene plastic sheeting for a vapor barrier. Hope this helps answer your question. Thank You -