Second Underlayment for Coretec Pro LVP?

3 years ago

What material do you recommend for a second underlayment under Coretec Pro lvp? These are going in a basement over a concrete subfloor in the Pacific Northwest. House is 80 years old, and knock wood, water has never been an issue. Insulation from the concrete is a consideration. The Coretec has a thin cork underlayment attached.
I've talked to the manufacturer and extensively researched different options, but hoping to get some firsthand feedback on plastic sheeting vs. cork as a second underlayment. Open to recommendations on specific products.

Sort by:Oldest

Comments (6)

SJ McCarthy
3 years ago
NOTHING. Sigh. You have purchased a CoreTec product with a backing. That means you are done. You can purchase a CoreTec product WITHOUT the backing. That leaves you free to use 3mm cork underlayment. You are not allowed to work with underpad with 97% of all vinyl products.

If you want insulation you need to work with a floor that allows it = LAMINATE. A HIGH END laminate ($5/sf) can handle 12mm cork underlay (1/2"). That is serious insulation! All for $1.49/sf.

If you insist on the CoreTec Plus AND insulation then you MUST work with a rigid subfloor system like DriCore. It offers a floor raise of 3/4" (19mm) Then the thickness of the CoreTec 8.5mm. This will cause a 1" floor raise.

Do you have the ceiling clearance for this? How about the stairs?

Personally I would go with 6mm cork underlay (1/4") and a 12mm (1/2") European laminate (Lico, Kahrs, etc) and be done.

If your basement has moisture issues (either from above or below...it doesn't matter) you will loose whatever floor you put down. That includes the CoreTec. Yah. No one tells a purchaser that is the cost of a 'little flood' in the basement.
lafala
Original Author
3 years ago
Coretec allows a second underlayment up to 3mm on this particular flooring. We don't need the heavy duty insulation of Dricore (though we have the ceiling height to accommodate if we did). Moisture is not an issue.

I've researched extensively and spoken with Coretec customer service multiple times. Using a second underlayment may not be standard practice but it is fairly common and within warranty. Curious to hear directly from people who have gone this route.
Related Professionals
Cedar Rapids Flooring Contractors · Faribault Flooring Contractors · Panama City Beach Flooring Contractors · Scottsboro Flooring Contractors · Four Corners General Contractors · Bay Shore General Contractors · Greenville General Contractors · Pocatello General Contractors · Shorewood General Contractors · Morton Grove Interior Designers & Decorators · Plainfield Architects & Building Designers · Oswego Flooring Contractors · Panama City Beach Flooring Contractors · St. Johns Flooring Contractors · Trenton Flooring Contractors
Jenn A
2 years ago
Hi Lafala - I am in the middle of basement reno and considering to purchase Coretec vinyl plank with attached underlayment which is pretty thin. I wanted to put another underlayment on top of the concrete to really keep the cold out. Did you end up going this route and are you happy with your decision? Which underlayment did you go with? I was also considering Dricore with Coretec on top but not sure if I need to do that.
ezcamins
last year
Same boat as you Jenn. Not sure if we'll do just 6mil poly moisture barrier, and then the coretec which has cork backing or if we'll add an additional underlayment. What are you doing?
Scotty D
last year
I put 2mm rubber under my cortec vinyl floor, it made it much more solid and deadens the sound. I bought it at the isostore. If you have moisture issues, you might not be able to use it.
ezcamins
last year
Thanks Scotty! Do you have any issues with the cork squeaking against the rubber? How about the locking mechanism?