Due t o t he incr easing dem and for high quality residential dw elling s, w ood fr am e hou ses ar e being con struct ed in Korea at a rat e of over 1000 per y ear and t he num ber is expect ed t o r each ov er 5000 per year in the next four t o fiv e y ear s . In addition , if the proposed am endm ent t o t he law regarding w ood con struction building s is pas sed, the dem and for light - w eight mult i- family w ood construct ion building s w ill increa se, and as a result , there will be an incr eased need for r esearch and study int o variou s aspect s of qualit y enhancem ent and impr ovem ent of w ood con struction . In particular , in or der t o improv e the quality of r esidential surr ounding s, special
att ention w ill hav e t o be paid t o the issue of noise contr ol bet w een dw elling unit s .
T his report inv estigat es and ex am ines sound and noise isolation regulation s and docum ent s r elat ed t o w ood con struction in other countries and m easur es the perform ance of sound isolation relat ed t o w ood con struction in Korea . Based on the r esult s of t he inv estigat ion , t his r eport proposes a st ructur e for sound isolation applicable t o light - w eight w ood con struction in Kor ea .
1. F act or s that effect t he sound isolat ion perform ance of light - w eight multi- family w ood con struction dw elling s include type of m at erials and m ethod of a ssem bly u sed for w alls and flooring/ ceiling s, location , type, t hickness and air - tight ness of opening s (window s and door s ), and the qualit y of con st ruction, et c .
2. In order t o improve t he sound isolation perform ance of ext erior w alls , it is recom m ended that 2x6 w ood studs that pr ovide great er structural safety and lar ger air space be u sed in st ead of 2x4 w ood studs . In addition , sound isolation perform ance w as found t o be greatly influenced by the pr eservation of air - tightnes s when in st alling opening s such as w indow s and door s .
3. In case of int erior w alls , it is concluded that the u se of t w o layer s of gypsumboard, w hich w as found t o hav e similar sound isolation
perform ance and is r elatively cheaper , is m or e fav orable t han resilient channel u sed for soundproofing w hich is difficult t o w ork with and giv es rise t o high m at erial cost s and labor cost s . In particular , u sing fir e- resist ant gypsumboard on the out er layer of the t w o lay er of gy sum boar d is found t o hav e great er sound isolation perform ance and fir e safety .
4. It is confirm ed that 2x4 double w ood st uds w ith one inch air space is t he m ost appropriat e structur e for partition w alls bet w een dw elling unit s .
5. Since it is cu st om ary in Kor ea t o inst all a type of floating floor called on d ol in dw elling unit s, one m ay u se a sound isolat ion m at as a buffer t o incr ease sound isolation perform ance by u sing a leaving a space bet w een the on dol and the w all and inst alling the sound isolation m at in the gap and m aking it air - tight so as t o pr ev ent cont act bet w een the edge of the on dol and the w all and caulking . How ev er , ev en though the partition w alls and floor s/ ceiling s bet w een unit s pr ovide good sound isolation on their ow n , if there is no caulking at the struct ur al joint s , flanking transmission m ay occur r esulting in a rapid decrease in ov erall sound isolation perform ance. T herefor e, it is v ery import ant t o caulk and m ake air - t ight all gaps that m ay allow for the transmission of sound.
6. T he result s of the m ea surem ent s of sound isolation perform ance of dom estic w ood con struction building s indicat e that floor s hav e a rat ing of L- 65 for heavy w eight impact sound, L- 75 for light w eight im pact sound, and IIC 44, and partition w alls bet w een dw elling unit s r ecorded r ating s of D- 50 and F ST C 59. T he m easurem ent r esult s for floor s/ ceiling s w er e satisfact ory in com parison t o sound isolat ion r ating s for single- family dw elling s in other count ries ; how ev er , t he r ating s w ere not adequat e enough for application in m ulti- fam ily dw elling s . A ccordingly , if it is pr esum ed that dom estic con struction is sim ilar t o that of the subj ect specim en , light - w eight m ulti- family w ood con st ruction needs t o r einfor ce sound isolation perform ance for floor s/ ceiling s .
7. In conclu sion , w hen con structing light - w eight multi- family w ood con struction dw elling s , it is suggest ed that a structure similar t o F igur e 40 in Chapt er 6 be u sed t o r egulat e any noise that m ay arise bet w een dw elling unit s . T his is based on m inimum r ating s of L- 55 and IIC 55 for floor/ ceiling s bet w een dw elling unit s and D- 50 and ST C 60 for partition w alls bet w een dw elling unit s .
Keyw ords : Light - w eight mult i- family w ood con st ruction, noise, sound isolation perform ance, air - born sound tr an sm is sion , st ructur e- bone sound transmission , D, L, ST C (sound t ran smission class ), IIC (impact in sulation clas s ).