The underlayment has a plastic strip on one finish that goes alongside the wall and up the wall that will likely be lined by the baseboard, and the opposite finish has a strip of adhesive tape. As you unroll every roll, the clear plastic finish lies on prime of the top with adhesive strip and two white items of froth will likely be butted up in opposition to one another.
Tip: Make certain the 2 white sides are as shut as they are often and lay one over the opposite and tack it down. That is how you’ll know if it is on the other way up — if the tape strip is down, it’s backwards. It is essential that the underlayment run the identical path because the flooring.