Due to the fact that low-rise semi-detached buildings have a light construction, for the most part they usually do not meet the requirements for sound insulation, even those that apply to multi-storey block houses with massive walls.
To ensure effective sound insulation between adjacent (neighboring) sections, it is necessary during construction to perform a special deformation layer between them. In other words, every house should have its own walls. A special air gap about 3-5 cm wide is left between the walls of neighboring houses. The seam should be along the entire height of the house from the foundation to the roof ridge.
The gap is usually filled with mineral wool. A properly insulated wall between sections of houses provides a 50 dB noise reduction, which provides complete sound insulation from the airborne noise of neighboring premises.
Walls with a two-layer structure (made of brick or cellular concrete) with an air gap, with a thickness of each layer of at least 25 cm, also have high noise insulation characteristics. It is important that a high degree of accuracy is observed during the laying, so that there are no remains of dry mortar or pieces of wall material in the air gap, since debris between the layers can significantly impair the soundproofing properties of the wall. For semi-detached houses or twin houses, the required value of the sound insulation index should be in the region of 50 dB.
From the outer part of the wall, the expansion joint, as a rule, is closed with a special elastic bar, or sealed with an elastic tape. Despite the fact that in semi-detached houses the walls are separated from each other with the help of a deformation layer, you should still not forget about the sound insulation of the floors in order to protect yourself from impact noise from neighboring houses (blocks). In order to provide yourself with comfortable living conditions, it is necessary that the floors of the house absorb noise at least 41 dB. In this case, the value of the reduced level of impact noise under the ceiling should not exceed 67 dB. Soundproofing measures must be carried out using soundproofing materials that have sufficient elasticity and compressive strength.
In order to provide yourself and your family with a quiet and peaceful living in the house, it is necessary to take care of effective sound insulation even at the construction stage.