PAGE UNDER CONSTRUCTION
Often the suppliers will sell a "standard" stock underlay with minimum reference to the sub-strate floor in the room. The sub-strates are
- solid concrete
- screed concrete on Styrofoam
- wooden floor boards
- chipboard (wayrock)
Concrete floors are either resting directly on the earth below the ground floor or poured onto a PVC damp-proof membrane, Styrofoam blocks or free flow Styrofoam depending on the building regulations in force at the time of construction (and decision of the builder). The condition of the damp-proof membrane below the ground floor is not easy to access so for laminate, engineered board and LVT (Luxury Vinyl Tiles) the underlay must include a damp-proof membrane. Personal opinion is that if you have rising damp in your home is better to know about it
Damp-proof membrane underlays for Laminate and Engineered wood flooring.
A range of dpm products are available which can be categorised by weight and thickness, together with the inclusion of a reflective silver or gold layer. The reflective layer should be fitted facing the earth to bounce back the cold? My understanding of physcis is that light is reflected but cold in the dark will pass through the reflective layer by conduction, so reflective layers are of limited value. However, the best quality dmps include the reflective element at very little additional cost compared with the basic products.
Which dpm to fit depends on how level the concrete screed is. A slightly imperfect concrete can normally be corrected with underlay. Really wonky floors will need self-levelling compound.