The invention relates to a sound-damping partition, especially for the internal equipment of buildings. The partition consists essentially of a timer sub-frame (10) and two sets of planting (18, 20) on either wide side (12, 14) of the sub-frame (10) leaving a hollow space (16) filled with air and damping materials (36). To obtain improved airborne sound damping suing simple means, the invention proposes that one of the sets of planking (20) be secured to the sub-frame (10) by means of thick-walled, soft elastic beads of adhesive (32) while the other set of planting (18) is rigidly clamped to said sub-frame (10).

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention is related to a sound-damping partition wall, especially for 
interior structures in buildings, comprising a sub-frame preferably 
designed to be a wooden frame or post construction, and two sets of 
planking on either broad side of the sub-frame, leaving therebetween a 
hollow space filled with air and/or damping material. 
2. Description of the Related Art 
In known partition walls of this type the planking is connected by 
mechanical means such as staples, nails, or screws to the wooden 
sub-frame. The acoustic damping values of such partition walls is not 
satisfactory, though, even when using thick-walled multiple planking. The 
sound attenuation that can be achieved therewith is in the order of 46 dB. 
An improvement of the damping values was in the past only possible with 
sub-frames in which the posts were replaced by profiled posts made of 
metal. The sound damping is therein improved by the internal elasticity of 
the profiled posts, which dampens the flexural vibrations, which are 
mainly responsible for the transmission of sound, when the planking is 
rigidly coupled to the posts. In the metal sub-frames it is found to be 
disadvantageous, though, that these, as opposed to the wooden sub-frames, 
cannot be used as load bearing walls. Therefore metal sub-frames are not 
liked to be used especially in the construction of pre-fabricated houses, 
more so since it would not fit into the production process of the building 
company which is usually equipped to work with wood. 
Based on this it is the object of the invention to improve a partition wall 
of the type described above such that an increased sound-damping can be 
achieved with simple means. 
SUMMARY OF THE INVENTION 
The solution according to the invention is based on the idea that the sound 
decoupling between the two plankings and the sub-frame can be improved 
when the two plankings can vibrate independently from each other. In order 
to achieve this, it is proposed according to the invention that at least 
one set of the planking is connected to the sub-frame by means of thick, 
softly elastic adhesive beads. The other planking is expediently connected 
rigidly to the sub-frame, preferably by means of staples, nails or screws, 
and thereby serves as a reinforcement plane for the static calculation. 
An adhesive which has a shear modulus of 0.1 to 0.3 N/mm.sup.2 at room 
temperature has proven to be especially advantageous. This value as well 
as the hardness according to the invention of 10 to 30 Shore (A) is very 
low compared to the adhesives usually used in wood connections and 
corresponds more to the values of elastic sealant materials. Due to the 
fact that the wall thickness of the adhesive beads corresponds to 
approximately 0.3 to 1.2 times their width and is about 3 to 10 mm in 
actual application cases, a certain amount of shear deformation within the 
adhesive beads has to be taken into account due to the weight of the 
planking. 
In order to keep the shear deformation within acceptable limits, it is 
proposed according to a preferred embodiment of the invention that the 
adhesive surface areas A of the adhesive beads are dimensioned such that 
under the influence of the weight of the planking a shear deformation of 
the adhesive beads of 5 to 25% of the bead thickness results. In other 
words, the adhesive surface area of the adhesive beads as a function of a 
unit area of the planking is advantageously 
EQU A=1/.mu..times.F/G 
with .mu.=0.05 to 0.25, 
wherein F denotes the weight per unit area of the planking, G the shear 
modulus of the adhesive and .mu. the shear deformation of the adhesive 
beads as a function of the bead thickness at room temperature. 
For a given bead size having an adhesive surface area A' per bead the 
number of beads per surface unit can be determined to be 
EQU n=1/.mu.A'.times.F/G 
with .mu.=0.05 to 0.25. 
The adhesive beads have on both contact sides essentially rectangular 
adhesive surfaces, wherein the aspect ratio between the long and the short 
side is expediently chosen to lie between 4:1 and 16:1. Advantageously, 
the long sides of the adhesive beads are vertically aligned with respect 
to the sub-frame and disposed vertically spaced with respect to each other 
on the vertical posts of the sub-frame. Two laterally spaced rows of 
adhesive beads may be disposed on each post of the sub-frame, wherein 
adjacent adhesive beads of the two rows of adhesive beads can be staggered 
in a zig-zag fashion with respect to each other. 
Double-sided foam adhesive strips disposed vertically on the posts of the 
sub-frame and acting as an aid during assembly may be provided in addition 
to the adhesive beads, which has a spacer function apart from keeping the 
planking in place until the adhesive beads have set. The adhesive beads 
are applied to the sub-frame in the form of triangular beads with the tip 
protruding over the adhesive foam strips, and are deformed to the wall 
thickness of the adhesive foam strips when the planking is mounted, 
wherein the adhesive surface at the tip side is broadened. 
Since the shear modulus of the adhesive decreases with increasing 
temperature and the shear deformation increases accordingly due to the own 
weight, a stop shoulder 40 for the glued planking can be disposed on the 
sub-frame as a safety measure, which stop shoulder is either elastically 
resillient or which is disposed below the lower edge of the glued planking 
projecting a distance corresponding to at least the bead thickness. 
The adhesive is expediently chosen from the group of polyurethane 
adhesives, silicone adhesives, butylene adhesives or a mixture of these 
adhesives, while the plankings may consist of or are composed of gypsum 
plaster boards, gypsum fiber boards, particle boards or plywood boards.

DETAILED DESCRIPTION OF THE INVENTION 
The sound-damping partition wall shown in FIG. 1 is intended to be used for 
the interior construction of prefabricated houses. It consists essentially 
of a sub-frame 10 designed as a wooden frame and two plankings 18, 20 
mounted thereto at the broad sides 12, 14, with an air filled hollow space 
16 formed therebetween. The frame forming the sub-frame 10 comprises a 
lower beam 22, an upper beam 24 and a plurality of posts 26 extending 
between the lower and upper beams and rigidly connected thereto. The 
plankings 18 and 20 are each made of two gypsum plaster boards and/or 
plywood boards which lie plane against each other and which are rigidly 
connected to each other by staples 28, 30 or other mechanical fasteners. 
The planking 18 is rigidly connected to the sub-frame 10 by means of the 
sufficiently long staples 28, while the planking 20 is connected to the 
sub-frame 10 by means of soft-elastic, thick-walled adhesive beads 32. In 
order to make the assembly of the glued planking easier, double-sided 
adhesive foam strips 34 are additionally provided, which serve as spacers 
and immediate fixing of the planking 20 to the sub-frame 10 until the 
adhesive beads 32 have set. The adhesive beads 32, which preferably 
consist of a polyurethane adhesive, are applied to the horizontally 
positioned sub-frame in the form of triangular beads with their tips 
protruding over the adhesive foam strips 34 and are deformed to their 
rectangular cross section according to FIG. 2a when the planking 20 is put 
on. 
In the embodiment of FIG. 2a the hollow space 16 is partially filled with 
an insulating mat 36 consisting, for instance, of glass fiber material. 
EXAMPLE 
For the production of a sound-damping partition wall a frame construction 
made of wood with square wood posts having sides of 80 mm length and being 
arranged at distances of 62.5 cm from each other is rigidly stapled at one 
broad side 14 to a double planking made of 12.5 mm thick gypsum plaster 
boards and glued on the other side to a similarly constructed planking 
consisting of two 12.5 mm thick gypsum plaster boards by means of adhesive 
beads 32 and an adhesive foam strip 34. The 70 mm long and 8 mm wide 
adhesive beads are applied as triangular beads with a tip height of 12 mm 
to the post surfaces 14 in the zig-zag shape shown in FIG. 2b on the left 
and right side of the corresponding adhesive foam strip 34. The same 
procedure is carried out on the upper and lower beams 22, 24. A two 
component polyurethane adhesive (SikaBond VP200195)is used as the 
adhesive, which is applied in pasty form. When the planking 20 is mounted, 
the adhesive beads 32 are deformed to the thickness (6 mm) of the 
double-sided adhesive foam strip 34 which acts as a spacer. 
The shear modulus of the adhesive used was G=0.19 N/mm.sup.2 in the set 
state. The adhesive area A' of each bead was 70 mm.times.8 mm=560 
mm.sup.2. 
The breaking elongation of the adhesive used was more than 500%, while the 
breaking elongation of glued gypsum plaster boards is more than 150%. 
The admissible shear deformation by the own weight of the planking was 
assumed to be .mu.=0.1, which corresponds to an admissible shear 
deformation of 0.6 mm for a bead thickness of 6 mm. The admissible 
deformation depends on visual inspection (usability) and on the maximum 
deformability of the connections (in this case gypsum). Thus there is at 
worst a 15-fold breaking security. 
From these values the adhesive surface area of the adhesive beads amounts t 
o 
EQU A=F/(0.1 G) 
wherein A denotes the adhesive area in mm.sup.2 /m.sup.2, F the area eight 
of the planking in N/m.sup.2, and G the shear modulus of the adhesive 
(here G=0.19 N/mm.sup.2). 
The number of adhesive beads per square meter planking is calculated to be 
EQU n=A/A' 
wherein A' denotes the adhesive surface area of each bead (here 560 
mm.sup.2). 
The examined partition wall had a surface area of 12.1 m.sup.2 and a total 
weight (density) of 51.5 kg/m.sup.3. The sound attenuation measurements 
were performed according to ISO/DIS 140-3 (1993) with an evaluation 
according to ISO/DIS 717-1 (1193) using wide band noise as test sound and 
a third-band filter on the receiver side. The results are shown in the 
diagram of FIG. 3. A comparison with the norm reference curve B.sub.v 
shown in dash-dotted line shows an average sound attenuation R.sub.w =52 
dB. This sound attenuation value is at least 6 dB larger than for a 
corresponding partition wall in which both plankings 18, 20 are stapled to 
the sub-frame. 
In summary the following is to be stated: The invention is related to a 
sound-damping partition wall, especially for interior structures in 
buildings. The partition wall comprises a wooden sub-frame 10 and two sets 
of planking 18, 20 on either broad side 12, 14 of the sub-frame 10, 
leaving therebetween a hollow space 16 filled with air and damping 
material 36. In order to achieve improved sound damping properties by 
simple means it is proposed according to the invention that at one set of 
the planking 20 is connected to the sub-frame 10 by means of thick, softly 
elastic adhesive beads 32, while the other set of planking 18 is rigidly 
stapled to the sub-frame 10.