| |
DECIBEL2 may be an integrated part of different floor structures the same
way as we describe under DECIBEL3 (the Sound-Seal structure). Naturally,
the DECIBEL3 mat will give a better acoustic result, but the DECIBEL2 mat
offer a lower height of the finished floor, and that is often an important
requirement. Therefore, we recommend that DECIBEL2 is used as an alternative
to DECIBEL3 when the height of the finished floor is a critical
point and the
requirement for improvement of impact sound is moderate.
The basic principle, that we call SoundSeal, for the structure is that the
acoustic mat is trowelled with reinforced reshaping course (cement or gypsum based).
If the DECIBEL2 mat is used the thickness of the reinforced reshaping course may
be ≥20 mm's in comparison
to ≥30 mm's for DECIBEL3. Please, read the information
about DECIBEL1 in the SoundSeal structure when installing clinker & stone. |
|
|
| |
The applied trowelling should be completely detached from the floor stucture and
the walls (consult the sketch and the laying instruction). Essentially, DECIBEL2
may be used as an alternative in different structures. Please, read below about
an acoustic comparison between DECIBEL2 and DECIBEL3. |
|
|
|
|
| |
 |
Impact Sound |
|
| |
Difference between DECIBEL2 and DECIBEL3 |
|
| |
We have performed tests on concrete slabs without finishes and
they give
a hint of the difference between DECIBEL2 and DECIBEL3 in a SoundSeal
structure where the corresponding density (20 mm's trowelling) has been
on top
of the DECIBEL mats. |
| |
| |
Result: |
| |
| |
The index of the impact sound improvement (∆Līn,w) is approx. 4 dB poorer
for DECIBEL2 in comparison with DECIBEL3, and therefore we primarily recommend
the use of the DECIBEL3 mat when the height of the finished floor permits.
However, the structure with DECIBEL2 is very often sufficient to reach the specified
requirements. |
|
|
|
|
|
|
 |
|
|
|
|
| |
Floating
Structures with Sheet Material |
|
| |
DECIBEL2 also works as an alternative to DECIBEL3 combined with self-supporting sheet
material like e.g. 22 mm's particle board, 18 mm's plywood, minerit, cement based particle board or
2 x 13 mm's gypsum floor board. Since the filling above the DECIBEL mat is important a sheet material
as heavy as possible is primarily recommended. That will help affecting the lower frequencies.
To install double layers of a sheet material will help overlapping joints and that will yield a
stronger structure unless tongue-and- groove-joints are an option. |
 |
|
| |
| |
The DECIBEL2 combination should primarily be used where the
height of
the finished floor is a factor. In other cases we refer to DECIBEL3. |
|
| |
Example: Difference Between
DECIBEL2 and DECIBEL3 under Sheet Material |
|
| |
To what extent DECIBEL2 reduces the level of impact sound does, of course, depend
on what the structure is like and what combination the mat is integrated with. Other factors also make
a difference like e.g. the size of the room etc. To indicate the difference between DECIBEL2 and
DECIBEL3 in a structure with sheet material we have chosen the following example. |
|
| |
 |
|
In the adjacent graph we show the difference of the improvement of the impact
sound if we compare DECIBEL2 and 3 under a plywood sheet. This test indicates the value of moving
up one class to DECIBEL3. |
|
|
| |
Result: |
| |
|
The difference between using DECIBEL3 by comparison with DECIBEL2 is approx.
2dB improvement (100-3150Hz), which in
some cases could be decisive to pass
the acoustic requirement. |
|
|
|
|
|
|
