Laminate flooring’s versatility allows it to be laid directly over concrete but necessitates using an underlay between the concrete and the laminate. A thin cork, rubber or foam membrane is laid over the concrete to create a barrier between the floor and subfloor. While certain brands of laminate flooring come with a built-in underlay, if you're laying the laminate over concrete, you must install a moisture-proof membrane. In addition to providing noise protection, an underlay also helps keep the room warm.
Properties of Concrete
Once poured, a concrete subfloor maintains a moisture level from the ground beneath. The concrete must be completely dry before laminate flooring can be installed. Add the moisture barrier on top of the concrete to create a wall between the laminate and the concrete.
Acclimatizing the Laminate
Like natural or engineered wood, laminate flooring must cure to the temperature of the room for several days before being installed. This prevents the laminate from expanding or contracting after installation, prevents warping and ensures a tighter fit, all of which help add warmth to the room.
Cork, rubber or foam, the most frequently used underlays, even out a concrete subfloor and facilitate installation of the laminate. The underlay also acts as insulation, keeping the room warm in winter and cool in summer. An underlay plus a damp-proofing membrane must be laid when installing laminate over concrete.
A separate damp-proofing membrane must be purchased separately from the foam underlay. A combination of foam and rubber consists of a rubber barrier with compressed foam chips. Cork, the most expensive underlay, is thin and excellent for soundproofing but requires a separate damp-proofing membrane. If warmth is the goal of your underlay, select a mid-range combination underlay that has a moisture barrier on the bottom or lay a separate moisture-reducing membrane.
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