Pre-certified and poor construction... Countermeasures against floor noise?

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Continuous report on the interfloor noise problem Today (26th) In the second order, we will examine why our apartment is so vulnerable to interfloor noise.

We looked at the problems of construction companies' unsuccessful construction and even the structural part of the building from various angles and considered alternatives.

Reporter Park Chan-geun and Im Sang-beom will deliver.

<Reporter Park Chan-geun> The

noise from the wall makes couples sleep and their children often startle.

"It's an interfloor noise", "No." The cause of the noise was finally caught in the ears of the couple who had quarreled with the upper and lower houses and went to the police station.

[Daegu City Apartment Residents: I heard the sound from a place I didn't really think of, so I looked for the cause all night and it was the sound of the elevator.] I

protested several times to the contractor through the management office, but nothing improved.

[Daegu City Apartment Residents: Will all households tolerate elevator replacement after 3 years?]

This is not the only place in poor construction.

Let’s look at the audit report from the Audit Office in May 2019.

We selected 191 units of completed apartments to measure the inter-floor noise, and 96% of them had a lower grade than the pre-approved test before building, and 60% did not meet the standard at all.

To reduce inter-floor noise, concrete slabs, cushioning materials, lightweight aerated concrete, and finished mortar should be laid with proper materials in accordance with the prescribed thickness.

However, 88% of the apartments were poorly constructed, aiming to not be able to open the floor of the apartment.

If only pre-certification passes by gimmick, there is no way to prevent it even if it is roughly built with cheap materials during the actual construction process.

[Floor construction company president: The laboratory compresses 10 times, but at the site, compresses 3 times.

Then it will cost less, just lay it down and cover it.] The same

goes for public apartments built with taxes.

This is an internal document of Korea Land and Housing Corporation LH obtained by SBS.

Inexpensive floor cushioning materials are being used with the lowest bidding and dumping orders, there is no way to sanction them, and it is said that reconstruction is difficult.

There is also a point that residents may request damage compensation for failure to meet standards.

LH clarified this as "a document written to improve the problem, not to neglect it."

The bigger problem is that it is not easy for residents to conduct class action lawsuits against construction companies even under these circumstances.

[Min Dong-hwan/Attorney: Litigation costs will not be high enough for some households to bear.

If it is rumored that there is an inter-floor noise problem, it seems that many people think it is a bigger problem.]

<Reporter Sang-beom Lim>

There are also attempts to change the structure of the apartment altogether to prevent the inter-

floor

noise.

In Korea, wall-type structures are the most popular.

It is easy to construct and inexpensive, so most apartments have been built this way for over 30 years.

On the other hand, in Japan and Europe, there are many columnar structures without bearing walls.

In Korea, there were many pillar structures before the mid-1980s, and construction companies avoided that the business feasibility was poor due to the high floor height, but this pillar structure produced less noise between floors.

[Gimsuam / Korea Institute of Construction Technology: Now 35 layers, 50 layers so up do to the variability and the thought that goes into pillar approach that is preferable, and more than the noise side is also Wall advantageous]

Sejong City, the old columnar structure We built a'Jang Life Apartment', which means an apartment to go.

Built in a so-called'ramen structure' with columns and beams supporting the floor, this long-life apartment has a floor noise measurement of more than 5 decibels lower than that of a conventional wall-type apartment.

This is enough for residents to fully experience the noise reduction effect.

[Jin Mantaek/'Long Life Apartment' residents: Do not people live? It is very good as far as inter-floor noise is concerned.]

Plumbing is important in inter-floor noise.

When using the ceiling as a standard, the noise is reduced by replacing the pipe attached to the ceiling of the lower house with a layered pipe raised to the floor of the upper house.

[Park Ji-young/LH Land and Housing Institute: Because there are pipes inside our house, these pipe noises are less transmitted to the lower floors when using such water or when flushing the toilet.]

Construction companies are competitively introducing new technologies to reduce

floor noise.

It is time to consider not only possible incentives, but also strong penalties such as punitive damages for insolvent construction.

(Video coverage: Kim Tae-hoon, Video editor: Park Ki-deok, VJ: Jung Young-sam·Jeong Han-wook, CG: Hong Seong-yong, Choi Jae-young, Lee Ye-jeong, Seong Jae-eun, Jeong Si-won)