When it comes to using acoustic underlay in outdoor areas such as patios and decks, there are certain considerations that must be taken into account. The lower layer of the floor covering must be acoustically tested to determine how much impact noise it reduces. This is because not all underlays are created the same way, so you can't assume that a 5mm underlay will work the same as another. The primary purpose of an acoustic floor base is to reduce the amount of impact noise that crosses the floor, which is caused by falling objects, footsteps, and the movement of furniture over hard surface finishes of any type of building.
In some places, there are no requirements or local legislation, so it's good to have an acoustic base for floors. In these situations, it is almost always necessary to use an acoustic floor layer to meet these standards. When selecting an acoustic underlay for outdoor areas, it is important to consider the type of flooring that will be used. For example, if you are using a wooden decking, then you should choose an underlay that is specifically designed for this type of flooring.
Additionally, you should also consider the environment in which the underlay will be used. If the area is exposed to extreme temperatures or moisture, then you should choose an underlay that is designed to withstand these conditions. Finally, it is important to ensure that the acoustic underlay is installed correctly. This means that it should be laid flat and securely fastened to the subfloor.
Additionally, any gaps between the underlay and the subfloor should be filled with a suitable sealant or adhesive.