Do I Need an Additional Underlayment or Vapor Barrier for Arista Laminate?
Arista comes with pre-attached underlayment, so no additional underlayment is needed. A vapor barrier is required when installing on a concrete slab.
No Additional Underlayment
The pre-attached underlayment handles cushion, sound dampening, and minor subfloor smoothing. Adding more underneath weakens the floor, a softer base lets planks flex under foot traffic, stressing the click-lock joints and leading to gaps over time.
The one exception: If your HOA requires a higher sound rating, you can add up to 1 mm of firm, rated acoustic underlayment to stay within the 3 mm total underlayment cap. Avoid anything soft or spongy.
Don't use foam to match an adjacent floor height. Level the subfloor itself with plywood, luan, or self-leveling concrete.
Vapor Barrier Over Concrete
A vapor barrier is required any time Arista goes over a concrete slab, on-grade, above-grade, or below-grade. Without it, slab moisture can migrate into the HDF core and cause mold or pressure buildup underneath.
Use a 6 mil polyethylene vapor barrier sheet run continuously across the slab with seams overlapped and taped (2" minimum, outdoor-rated or packing tape).
New concrete must cure for at least 60 days. Moisture emissions should be below 5.0 lbs per 1,000 sq ft over 24 hours. Slab RH below 75%.
For full installation documentation, visit our Technical Resources page.
Common Questions
Can I install over existing tile, vinyl, or laminate?
In most cases, as long as it's flat (within 3/16" over 10 ft) and firmly attached. See Can I Install Over an Existing Floor?
Do I need a vapor barrier if my slab is sealed?
Yes, a vapor barrier is still required. A slab sealer doesn't replace a dedicated 6 mil moisture barrier.
Do I need a vapor barrier over radiant heat?
Yes. Keep the system below 85°F at the floor surface and run it before installation to drive off residual moisture.
Will extra underlayment fix an uneven subfloor?
It will not, and should not be used to do so. Cushion compresses in low spots and creates flex under load. Level the subfloor first. See How Flat Does My Subfloor Need to Be?
Questions? Email support@flooret.com or call 1-800-700-8122.