We can admire the beauty, the texture, the luster and the faithful reproduction of natural wood or stone because we can see it. But what you can’t see – the floor’s underlayment – is just as important and deserves just as much attention.What is laminate flooring underlayment?Underlayment, or “padding” as it’s often called, is the spongy, closed-cell plastic foam sheet that comes in rolls. It is rolled out between the actual laminate flooring planks and the subfloor.Very often, particularly in a below-grade installation on a concrete basement floor, a vapor barrier is recommended in addition to the underlayment. That vapor barrier would go between the subfloor and the underlayment. “Combination underlayments,” as described on learn.builddirect.com, include an attached vapor barrier. Some laminate flooring planks come with the underlayment attached to each plank. Underlayment is not optional. If your laminate planks don’t have it already attached, we recommend that you buy rolls of underlayment on which to install your laminate floor.Is laminate flooring underlayment important?Its importance can’t be overstated. INSTALLFloors.org says, “Underlayment and subfloors are, arguably, the most important aspect of any flooring project in both residential and commercial settings. Proper selection and installation of underlayments and subfloors is crucial to the proper wear and stability of any flooring.”How does laminate flooring underlayment work?Underlayment does two things that are critical to a successful laminate flooring installation:1. Underlayment takes out any minor deviations in the subfloor.2. Underlayment delivers superior acoustical performance.If your laminate flooring planks already have an underlayment pad attached do not use additional underlayment because doing so will void your Swiss Krono warranty.What sizes do laminate flooring underlayments come in?According to homerenovations.about.com, laminate underlayment is foam that comes in rolls that are usually about 3 feet wide and between 30 and 100 feet long. Thicknesses range from 6 mil to 8 mil.Vapor barriers and laminate flooring underlaymentIf your installation is over concrete, we recommend a 6-mil-poly vapor barrier – even if the underlayment you are installing already has a vapor barrier attached. Why? Unintended nicks or tears during the installation process can violate the integrity of the attached vapor barrier. Adding another vapor barrier is an extra level of protection.Will carpet or carpet padding work like a laminate flooring underlayment?No. Our product cannot be installed over carpet or carpet pad so these items must be removed prior to installation. This is for the same reason adding additional pad is not recommended.Is there a quality difference in laminate flooring underlayment?Yes. We recommend spending as much on underlayment as you can afford because performance generally follows price in underlayments. The white underlayments are usually the least expensive and don’t perform as well.