Lumber Liq 4mm LVP - Underlayment choice

[Daria B.]

Hi all,

Help please!

At the home stretch of this rental rehab. Demo has begun and Lowe's will be delivering items next week.

Flooring has been the biggest difficulty to get locked down. Going with a LVP waterproof I looked at tons of options (mm, foam backing, no foam backing, rigid core) with every flooring "expert" that I spoke with having no consistency on what I should use as underlay or if I should use underlay. I was quite surprised, aren't they supposed to know??

Now, finally, decided on Lumber Liquidators 4mm product https://www.lumberliquidators.com/ll/c/Edgewater-O...

The question now is underlay that I got no real answers on when speaking with those working in the flooring section. Seems like they just want to sell me high end when it's not needed after telling them it's a rental and I want something that is not high end but that will still do the job. 

There are two different subfloors being covered: concrete (300 sq ft) and the remainder (>1200 sq ft) is wood never finished that used to be covered with carpet. It's a townhouse with 3 levels and it's a rental, it's a rental, it's a rental. :-)

LL suggested putting this down: https://www.lumberliquidators.com/ll/c/LVT-Underla...

At $45 per 100 sq ft roll this is a very expensive underlay. Part of the write up "Ultra-Fresh: anti-microbial protection which resists mold and mildew" that should be sufficient to cover both subfloor types, but I don't want to spend that much money.

I need some help from those who have used similar or same flooring and what you decided to do for underlay.

What have you done for underlay that would be for a waterproof LVP covering concrete or wood subfloor?

Thank you!