Overview of the acoustic quality of dwellings in Ukraine and CIS

countries Yevhen Fridlib 1 Acoustic Consulting LLC Mayakovski 49a st, 98, Kyiv, Ukraine

ABSTRACT At least 10 million square meters of dwellings have been built in Ukraine per year. Most of them are residential complexes in cities. What is the level of acoustic comfort in these buildings? What are the main complaints of residents? We will answer these questions in this report. The most popular partitions and floors types, their main problems and methods how to improve sound insulation will also be shown. We will analyze the requirements of national standards and assess how modern houses meet these requirements.

This article shows the acoustics characteristics of many structures measured on site, taking into account various flanking transmission pathways. Particular attention is paid to additional insulation structures that are used in apartments, to the differences between laboratory meas- urements and field measurements. 1. INTRODUCTION

More than 75% of the population of Ukraine lives in cities, at least that was the case as of 2021. The vast majority of residential assignments in cities are apartment buildings of different eras. In terms of structures, buildings can be divided into 3 groups.

1.1 Built before 1955. About 15% of residential buildings

Mostly low-rise buildings up to 5 floors. Thick brick walls in most cases. But sometimes there are thin partitions that appeared in the process of reconstruction and the division of large apartments into several separate ones. Ceiling and floor types can be varied - wooden, vaulted, made of concrete slabs and monolith concrete on a metal frame. For this type of building, the main problem is vertical sound insulation - airborne and impact sound.

1.2 Built between 1955 and 2000 year. The vast majority of housing - about 65 %.

In the early period, there was an active construction of "Khrushchevka" - prefabricated 5-storey buildings. Floor is a thin concrete slab 50-60 mm, the walls are plaster blocks or thin bricks. Sound- proofing in such houses is disgusting. Now, there are still many such houses, but they are gradually being demolished and reconstructed.

Panel (prefab) houses of 9-16 stores are the solutions necessary for a quick recovery after the Second World War. Such buildings make up the majority of apartments in almost any city in the post- soviet area. Walls between apartments - concrete panel 140-180 mm thick. According to the results of field measurements, the sound insulation of such structures is 𝑅` 𝑤 = 47 … 52 dB. The value of sound insulation depends both on the thickness of the panel and on the quality of the work on sealing the seams and joints between the panels.

The most common flooring is a multi-hollow slab with a thickness of 220 mm - Fig. 1. During construction, a leveling screed 40-50 was carried out over the slab, laid on a layer of sand or small

1 eugen.acoustic@gmail.com

worm 2022

construction debris. This design could achieve airborne noise isolation up to 𝑅` 𝑤 = 52 dB, but impact sound isolation has always been a problem. To reduce impact noise, it was proposed to use linoleum on an elastic substrate or wooden floors with substrates (in fact, substrates were almost never used). After the collapse of the USSR and the growth in the welfare of the people, during renovations in apartments, the screeds were dismantled in order to increase the height by 4-5 cm (before that, the average height in houses was 2.4-2.5 m) and as a result, the sound insulation of airborne and impact noise decreased. For such a floor slab with a thin screed 𝐿` 𝑛𝑤 = 72…76 dB.

Figure 1. Hollow core slab

In addition to panel houses, houses up to 9 floors with load-bearing brick walls were also built, but the key difference from the first group is the predominant use of lightweight concrete floor slabs.

Soundproofing requirements according to the standard that was valid from 1977 until the end of the 2000s: 𝑅 𝑤 > 52 𝑑𝐵 , 𝐿 𝑛𝑤 < 60 dB [1]. Both of these criteria were rarely met in reality.

1.3 Modern construction after the 2000s

The predominant use of frame-monolithic technology. Apartment buildings with a height of 5-30 floors. The floor slab is monolith concrete with a thickness of 160-220 mm, which basically provides sufficient airborne sound insulation. Partitions between apartments - filling with various blocks. The use of heavy and lightweight bricks, hollow ceramic blocks and expanded clay concrete blocks, aer- ated concrete blocks and heavy concrete blocks is approximately equally popular. Less popular are three-layer partitions with a double contour and an air gap (sometimes filled with a sound absorber). Plasterboard frame partitions have begun to gain popularity only in recent years.

Nowadays, frame-monolithic technology is predominantly on the market and it will be going on further. Panel houses and other buildings construction types are also being built, but in very small numbers.

2. Sound insulation in modern construction in Ukraine

Consider the main solutions that are used in new construction and to solve soundproofing prob- lems in existing houses.

2.1 Impact noise insulation

A monolithic floor slab with a thickness of 200 mm usually provides airborne sound insulation within 𝑅` 𝑤 = 51. .54 dB . The differences are caused primarily by flanking noise transmission and re- radiation by partitions and facades. Impact sound insulation with bare slab 𝑳` 𝒏𝒘 = 𝟕𝟎… 𝟕𝟑 dB.

According to the current standard in Ukraine, the required isolation between dwellings is 𝑹` 𝒘 > 𝟓𝟐 𝒅𝑩 , 𝑳` 𝒏𝒘 < 𝟓𝟓 [2] . For airborne sound insulation they are in most cases met by such slab, but additional solutions are needed to achieve impact sound insulation requirements. The most pop- ular is the implementation of a "floating floor"- screed on a thin elastic layer. Let's give an example for two common types - rolled fibrous material and chemically cross-linked foamed polyethylene material (PE foam). The use of these materials is justified by the low price and ease of installation.

In real field conditions, impact noise insulation was measured in a residential complex, where, under equal conditions, a screed was made: over a layer of fibrous material 4 mm and PE foam 10 mm. Base floor slab - 160 mm. Table 1 shows field insulation improvement results and laboratory characteristics for these materials.

Table 1. Compare of lab and field effectiveness of different materials

Lab impact sound insula-

Field impact sound insula-

tion improvement index,

tion improvement in-

Material

Deviation, dB

∆𝑳𝒏𝒘 , dB

dex, ∆𝑳`𝒏𝒘 , dB

Fiber 4 мм 27 25 2 PE foam, 10 мм 31 21 10

The main reason for such serious deviations between laboratory and field measurements is the condition of the slab. In the laboratory, the slab is perfectly smooth, but in real conditions, the building culture is such that as a result of pouring concrete, many inhomogeneities of 2-10 mm remain on the surface of the slab - Fig. 2. As a result, air-filled materials are subject to greater local deformation and compression than fibrous materials, even with greater thickness.

Figure 2. Surface of the slab

In addition, mineral wool, XPS and EPS are also used in housing under the screed. Our experience with XPS and EPS are extremely negative. Such solutions make up no more than 5-7% of the total volume of new construction.

2.2 Airborne noise insulation

The designs of partitions between apartments are very diverse. Table 2 shows the results of field measurements for the most popular structures. The results were obtained for the conditions of instal- lation of partitions from column to column, without pronounced weak points in flanking paths. These structures are distributed in approximately equal proportions in modern residential buildings.

Table 2. Comparison of acoustics characteristics of common materials

Material type 𝑹` 𝒘 , dB Description

Aerated concrete 200 mm, density 500 kg/m3. In addition to its own low insulation, it has a property to re-emit sound, which worsens the overall insulation.

41…43

100 mm aerated concrete + 50 mm mineral wool + 100 mm aerated concrete. Even more sonorous compared to 200 mm thickness.

45…46

Ceramic block 250 mm, density 800-1200 kg/m3. There are many modifications with varying degrees of voidness. Some are close to regulatory requirements for sound insulation.

47…51

51…52 Brick 250 mm, density 1500-1700 kg/m3.

Hollow blocks made of lightweight concrete 190-200 mm, density 800-1100 kg/m2. There are many modi- fications, but almost they don`t meet the requirements.

43…47

49…52 Hollow blocks made of heavy concrete, 190-200 mm, density 1600-1800 kg/m2

Looking on table 2, we can say that most of the structures do not meet the requirements for sound insulation. As a result, even in new houses, residents have to perform additional soundproofing. Typ- ical solutions for additional sound insulation are layered structures consisting of a sound absorbing layer inside (mineral wool), a massive layer on the outside (gypsum-based boards), which is fastened to the wall using elastic joints. The thickness of such structures is usually from 55 mm to 130 mm. Insulation improvement within 𝜟𝑹 𝒘 = 𝟗… 𝟏𝟕 𝒅𝑩 , depending on the insulation value of the base structure, thickness and elements of the additional insulation. One of the subjective requirements for partitions between apartments is their strength and protec- tion against burglary. Our people mentally don’t ready to live with a lightweight partitions. Therefore, frame structures are used mainly in offices and hotels. To ensure the implementation of such require- ments, typical plasterboard partition was tested with an additional sheet of metal between sheets of plasterboard - Fig. 3.

Heavy plasterboard Heavy plasterboard

Figure 3. Scheme and photo of partition Next, we show two examples of the use of such partitions and the significant difference caused by the flanking transmission of noise. This partition was evaluated under two different conditions - in- stallation from column to column (Fig. 4) and connection to a glass facade on one side (Fig. 5). The scheme of connection to the facade is shown in Fig. 6.

Fig 4. Partition Type A, 𝑅` 𝑤 = 55 (−1; −5)

Fig 5. Partition Type B, 𝑅` 𝑤 = 49 (−1; −4)

dB

dB

Fig 6. Scheme of partition connection to façade

The frequency characteristics of sound insulation are shown in Figure 7. Due to the significant influence of flanking paths, we can see reductions in insulation for the entire frequency range.

A aN

Figure 7. Graph of sound insulation

Else, the partition with the use of a metal sheet between two plasterboard layers showed a good result, sufficient to provide comfortable insulation in housing. In terms of thickness and ease of op- eration, this solution can be considered like one of the best in comparison with structures from various blocks.

3. CONCLUSIONS

There are problems with sound insulation in residential buildings of almost all ages. Such problems actual not only for Ukraine, in CIS countries general tendencies the same. Many citizens live in a state of passive dissatisfaction, many of them solve this issue with additional soundproofing.

eeePeeeeere 3 I

It is especially important to consider sound insulation when designing and building new housing. In Ukraine, there are rather strict standards for sound insulation, but there is no mechanism for mon- itoring their implementation. There are also problems with the correctness of the declared character- istics for many materials and the ability to use them from the side of the architects and civil engineers.

To increase airborne sound insulation in existing building, there are various solutions that are ac- tively used and don’t require significant costs. But the reduction of impact noise from upstairs neigh- bors is traditionally a problematic issue for finished housing. For a concrete floor, it can be solved either by installing a floating floor from above (usually the neighbors are not ready), or by complex insulation from below (it is costly and reduces the area). Therefore, the responsibility of the building developer to ensure regulatory and comfortable requirements is extremely important.

4. ACKNOWLEDGEMENTS

I write this paper in dark times during the war in Ukraine. So my acknowledges to INTER-NOISE 2022 committee for support and special conditions for participating the conference, to UK people and people of all other countries, who supports our defense against russian invasion. 5. REFERENCES

1. SNiP II-12-77 "Protection from noise" 2. DBN V.1.1 -31:2013. «Soundproofing in buildings and areas». 3. Livshin A., Fridlib Y., Elkin A., UDC 666.974 PROVISION OF NORMATIVE SOUND INSU-

LATION OF IMPACT NOISE IN RESIDENTIAL CONSTRUCTION. 4. ISO 16283-1:2014. Acoustics — Field measurement of sound insulation in buildings and of

building elements — Part 1: Airborne sound insulation 5. ISO 717-1:2013. Acoustics — Rating of sound insulation in buildings and of building elements

— Part 1: Airborne sound insulation 6. LUN Misto Analytics