Sound insulation of Swedish Wooden floors Delphine Bard

Transcription

1 Sound insulation of Swedish Wooden floors Delphine Bard Division of Engineering Acoustics University of Lund, Sweden Building regulation in Sweden The requirements for dwellings are fulfilled if (sound class C according to SS 25267): R w + C db L n,w 56 L n,w + C I, No certain requirement regarding annoying vibrations

2 Building regulations need an immediate update due to. Two buildings, one wooden one concrete, what will the end consumer choose? OBJECT 01 (wood) Do you have any specific demands? I want a dwelling with good sound climate The building fulfil sound class A Can you verify? I have measurement minutes from an accredited measurement company OBJECT 02 (concrete) Do you have any specific demands? I want a dwelling with good sound climate The building fulfil sound class A Can you verify? I have measurement minutes from an accredited measurement company L n,w = 35 db ( 48 db) L n,w +C I, = 48 ( 48 db) R w +C = 61 db ( 61 db) L n,w = 48 db ( 48 db) L n,w +C I, = 48 ( 48 db) R w +C = 61 db ( 61 db) Perfect Perfect

3 The measured curve? OBJECT 01 (wood) OBJECT 02 (concrete) db L'n L'nw+Ci = 48 db db k 2k 4k Hz General experiences in Sweden Wooden structures used for multifamily houses comprise nothing but wooden building parts or a combination of wooden building parts and gypsum plaster boards. No concrete or anhydride is normally used in the structural system A typical trend is also that the system becomes more and more light One typical application for light system is to build additional floors on existing heavy structures.

4 General experiences in Sweden Furthermore, Industries prefer to use wood solely since mixed material is something in between wood and concrete, Wooden industry really prefer to promote pure wooden constructions, not least due to the fact that the structure is kept dry during the erection. General experiences in Sweden Today, there exist some various types of building systems I. Volume elements a) Based on beams (most common) b) Based on homogeneous wood II. Flat elements connected in many different ways a) Based on light I-beams or normal wooden beams b) Based on homogeneous wood

5 Building systems examples volume elements (Maximum seven storeys so far) a) Based on beams (most common) i. BoKlok (SKANSKA and IKEA) ii. Lindbäcks bygg iii. Lelånghus AB b) Based on homogeneous wood i. Setra Group ii. Moelven Byggmodul Building systems examples flat elements (Maximum eight storeys so far) a) Based on beams i. Masonite Beams AB ii. Masonite Light element AB iii. And some others.. b) Based on homogeneous wood i. Martinsons Byggsystem ii. Moelven Töreboda

6 Volume elements Implies that the final results are more predictable due to some important reasons The volumes have all a maximum span due to transport limitations The joists are all similar, no special adaptations are needed and there is a minimum risk of failure on site (if the pads to prevent flanking transmission are carefully designed and mounted in factory on the prefabricated module) Volume elements Risks especially if the elastic layers between the elements are not adapted to the load All systems currently on the market uses (in Sweden) Sylomer Sylodyn Well documented characteristics, which also includes information that they will keep their characteristics in the long term

7 Cassette systems / Cassette elements The most common cassette element system. few measurements indicate expected values in vertical direction, L n,w + CI, = db, L n,w = db and R w + C = db. Cassette systems / Cassette elements Another cassette system, MFB ( available in different technical levels, MFB XL and MFB Light open system and still developing. expected values in vertical direction, L n,w + CI, = db, L n,w = db and R w + C = db

8 Volume based system with beams and Sylomer Floor Construction from above; Linoleum floor covering 22 mm particle board 45*225 wooden beams (145 mineral wool) [appr. 50 mm air between volumes] 45*145 wooden beams (95 mm mineral wool) mm gypsum board Wall mm gypsum / 45 * 145 mm wooden beams (145 mineral wool) / 30 mm air / 45 * 145 wooden beams (145 mm mineral wool) / mm gypsum R w + C appr. 60 db (both floors and walls) L n,w + C I, appr db (floors) Volume based system with Massive wood and Sylomer Floor Construction from above; 14 mm parquet on foam 12 mm Huntonit or 13 mm gypsum 140 mm massive wood [appr. 110 mm air between volumes filled with mineral wool] 45*145 wooden beams (145 mm mineral wool) 22 * 70 laths / mm gypsum board Wall (13 mm gypsum in some cases) / 90 mm massive wood (18 mm massive wood / 18 mm laths and air / 18 mm massive wood / 18 mm laths and air / 18 mm massive wood) / 45 mm mineral wool / 20 mm air / 45 mm mineral wool / 90 mm massive wood (13 mm gypsum in some cases)

9 Volume based system Stegljudsnivåkurva L n,w + CI, = 51 (Sound Class B) (Limit (SE) 52 db) R w + C appr. 55 to 60 db (both floors and walls) Fre kve ns, Hz Thank you Delphine.bard@construction.lth.se