FLOORING STRUCTURE

STRUCTURE PARQUET

English Abstract

The present invention relates to a flooring structure in which the beams (1,
8) of the flooring structure are not interconnected with one another apart
from in certain discrete points, for example in bearing supports. In this
instance, the bearing beams (1, 8) of the flooring structure do not
dynamically co-operate with one another in any significant manner. As a
result, improved footstep sound insulation will be obtained since the flooring
structure only reacts locally to a dynamic loading. The flooring structure
emits only sound in an area close to the applied dynamic loading. In the
flooring structure according to the present invention, the beams (1, 8) lie
considerably closer to one another compared with that which has previously
been normal for light wooden flooring structures. In one embodiment of the
present invention, the beams (8) and/or studs (10) placed between the beams
(1, 8) and floor panels (5) are provided with grooves (9). As a result of
these grooves (9) torsional and compression rigidity at the anchorage points
with the floor are reduced, which gives improved footstep sound insulation
compared with beams and/or studs without grooves.

French Abstract

L'invention concerne une structure parquet dans laquelle les poutres (1, 8) ne sont pas reliées les unes aux autres sauf au niveau de certains points discrets, par exemple au niveau des surfaces portantes. Dans ce cas, les poutres porteuses (1, 8) de la structure ne coopèrent pas dynamiquement les unes avec les autres d'une manière significative. Par conséquent, on obtient une isolation phonique (bruits de pas) améliorée puisque la structure ne réagit que localement à une charge dynamique et n'émet un son que dans la zone proche de la charge dynamique appliquée. Les poutres (1, 8) sont beaucoup plus proches les unes des autres que dans les structures planchers en bois légères existantes. Dans l'un des modes de réalisation, les poutres (8) et/ou les solives (10) placées entre les poutres (1, 8) et les panneaux de plancher (5) présentent des rainures (9). Ces dernières diminuent la rigidité en torsion et en compression au niveau des points d'ancrage dans le sol, ce qui améliore l'isolation phonique (bruits de pas) par rapport aux poutres et/ou solives non rainurées.

Claims

CLAIMS
1. A flooring structure comprising beams (1,8) designed to reduce
transmission of footstep sound, characterized in that
the beams (1,8) are dynamically disengaged from one another whereby
a force applied on a beam acts on said beam only.
2. A flooring structure as claimed in Claim 1, character-
ized in that the flooring structure consists of closely
adjacent beams (1,8).
3. A flooring structure as claimed in Claim 2, character-
ized in that the distance between the beams (1,8) is less than
the height of said beams.
4. The flooring structure as claimed in any of the preceding claims,
characterized in that the beams (8) are provided with
grooves (9).
5. The flooring structure as claimed in any of the preceding Claims,
characterized in that studs (10) provided with grooves
(9) are disposed between the beams (1,8) and floor panels (5).
6. The flooring structure as claimed in Claim 4 or 5, charac-
terized in that the grooves (9) in the beams (8) or the
studs (10), respectively, have through-going apertures (11).
7. The flooring structure as claimed in any of the preceding Claims,
characterized in that the flooring structure is
homogeneous in that it consists of closely adjacent beams (1,8).
8. The flooring structure as claimed in any of Claims 1-6 , char-
acterized in that the flooring structure is semi-homo-
geneous in that the space between adjacent beams (1,8) is filled
with a material (7) of low shearing rigidity.

2
9. The flooring structure as claimed in any of the preceding Claims,
characterized in that it is substantially manufactured
from wood, concrete or steel.

Description

CA 02360565 2001-07-13
WO 00/42266 PCT/SE00/00037
FLOORING STRUCTURE
The present invention relates to a flooring structure having improved
footstep sound insulation.
The acoustic properties in a building are often described as footstep
sound, airflow sound and structural sound. Footstep sound is defined as
sound which occurs in adjacent enclosures as a result of footsteps on
flooring structures, in stairways etc. Airflow sound is defined as the
sound emitted from the sound source into the ambient atmosphere by the
air. Finally, structural sound is defined as sound which is propagated
via the structure of a building.
In order to avoid irritation, it is desirable to restrict the sonic
transfer between different spaces or enclosures in a building as far as
is practically possible. The present invention specifically relates to
footstep sound insulation, i.e. to reduce, on dynamic loading, the
transfer of sound between two storeys and/or apartments. The term dy-
namic loading relates to that type of loading which occurs as a result
of footsteps on a floor.
In addition to the bearing wooden beams, a traditional flooring struc-
ture consists further of a floor and a ceiling. In the actual flooring
structure and between floor, ceiling and flooring structure, respec-
tively, there are normally various types of insulating material. There
may also be provided battens for supporting any possible insulation
between the beams and false ceiling panels. At their ends, the bearing
wooden beams are secured in the structure of the building.
The principle of today's homogenous flooring structures entails that
the individual wooden beams are united via steel bands, nails or glue.
Traditional light flooring structures are normally interconnected by
the intermediary of various types of panels on the upper and lower
sides. This implies that the flooring structure oscillates as an
equivalent, orthotropic, homogeneous plate in the event of a dynamic

CA 02360565 2001-07-13
WO 00/42266 PCT/SE00/00037
2
loading such as a footstep. This in turn implies that the entire sur-
face of the flooring structure emits sound out towards adjacent areas.
In prior art flooring structures, there is a large number of different
strata or layers. In the present invention, the same or improved sound
insulation will be obtained with a fewer number of layers. This affords
obvious advantages both as regards material costs and material consump-
tion.
If a homogenous flooring structure is employed, it is moreover possible
to use it as a "floor" during building work.
One object of the present invention is to reduce the footstep sound,
i.e. to reduce the drawbacks inherent in traditional flooring struc-
tures as described above in the event of dynamic loading. Naturally,
the flooring structure must satisfy the usual requirements as regards
mechanical strength, structural sound insulation and airflow sound in-
sulation, fire safety etc.
The footstep sound damping effect is obtained according to the present
invention in that the flooring structure only reacts locally to a dy-
namic loading, which entails that the flooring structure only emits
sound immediately adjacent the applied dynamic loading.
In a flooring structure according to the present invention, the bearing
wooden beams are not dynamically interconnected.
The present invention will now be described in greater detail hereinbe-
low, with reference to the accompanying Drawings. In the accompanying
Drawings:
Fig. 1 shows the principle of a homogeneous wooden flooring structure
with steel band according to prior art technology;
Fig. 2 is a cross section of a traditional light wooden flooring
structure according to prior art technology;

CA 02360565 2001-07-13
WO 00/42266 PCT/SE00/00037
3
Fig. 3 shows the principle of a homogeneous wooden flooring structure
according to the present invention;
Fig. 4 shows the principle of a semi-homogeneous wooden flooring
structure according to the present invention;
Fig. 5 is a perspective view of a grooved beam which may be employed
in the present invention; and
Fig. 6 is a schematic cross section of an alternative flooring struc-
ture according to the present invention.
The figures show substantially only the beams, the floor structure, in-
cluded in the flooring, but a person skilled in the art will readily
perceive that the flooring structure also includes floor, ceiling and
various insulating layers.
Today, basically only two types of wooden flooring structures are em-
ployed, namely a homogeneous wooden flooring structure as in Fig. 1, or
a so-called light wooden flooring structure as in Fig. 2.
The homogeneous wooden flooring structure according to Fig. 1 has a
number of closely adjacent wooden beams 1 which are united together,
for example, by means of two steel bands intimated at reference numeral
2 in Fig. 2. This is a relatively rigid construction. When such a rigid
construction is subjected to a dynamic loading 3, such as a footstep,
it oscillates as an orthotropic, homogeneous plate. This entails that
the whole surface of the flooring structure emits sound to adjacent ar-
eas, as intimated by the sketched sound waves 4.
In the normal construction of a light wooden flooring structure as in-
timated in Fig. 2, the beams 1 are interconnected with the aid of floor
panels 5 and ceiling panels 6. Also, in such a flooring structure, the
individual beams co-operate via the panels so that footstep sound 4 is
transferred from its entire surface towards adjacent areas.

CA 02360565 2001-07-13
WO 00/42266 PCT/SE00/00037
4
In a homogeneous flooring structure according to the present invention
as illustrated in Fig. 3, the individual beams 1 are not dynamically
joined together. The ends of the beams are secured in the structure of
the building. The present invention is based on the feature that the
bearing beams 1 of the flooring structure do not co-operate dynamically
with one another in any significant manner.
In all embodiments, according to the present invention, the beams 1 are
not interconnected with each other apart from at certain discrete
points, for example bearing supports at the ends of the beams.
Compared with prior art light flooring structures, the beams 1 in the
flooring structure according to the present invention lie considerably
closer to one another. A suitable rule of thumb in such instance has
proved to be that the distance between the beams 1 should be less than
the height of an individual beam 1.
When a dynamic loading 3 is applied on a flooring structure according
to the present invention, only the beam or beams 1 which lie directly
beneath the point of impact of the loading will be affected. The trans-
fer of movement to adjacent beams is minimized. In such instance, the
footstep sound 4 is only transferred via these directly affected beams.
The flooring structure may be said to react locally in that it only
emits sound immediately adjacent the applied dynamic loading 3.
As intimated in Fig. 4, the loca l reaction principle according to the
present invention also applies to semi-homogeneous flooring structures
without interconnected beams 1. In such instance, the beams 1 lie a
distance from each other and insulation 7 has been placed between the
beams 1. This insulation 7 must have low shearing rigidity. If the in-
sulation has too high shearing rigidity, there is a risk that the vi-
brations are transferred between the beams 1. An example of suitable
insulation material is mineral wool of low shearing rigidity. Also in
this case, the flooring structure reacts only locally to a dynamic
loading 3.

CA 02360565 2001-07-13
WO 00/42266 PCT/SE00/00037
In one alternative embodiment of the present invention, the local reac-
tion to a dynamic loading is attained in that the flooring beams in the
flooring structure under consideration are provided with grooves which
reduce torsional rigidity and compression rigidity at the anchorage
5 point to the floor and/or ceiling panels. The same effect is achieved
with separate, grooved studs in accordance with the foregoing which are
mounted on the upper and/or lower side of the flooring structure.
In this embodiment, use is made either of beams 8 or studs 10 which
have been provided with grooves 9. In such instance, the grooves 9 are
made in a manner illustrated in Swedish patent No. 510 722. The grooves
9 in beams 8 or studs 10, respectively, are fully open in one direction
and have through-going defined apertures 11 in the other direction.
Each cross section displays at least one part without any material,
i.e. at least one of the grooves 9 has no residual material in that
cross section.
When grooved beams according to Fig. 5 are employed, the floor may rest
direct on the beams. In the embodiment according to Fig. 6, grooved
studs 10 are placed between the beams 1,8 and the floor panels 5. In
this latter embodiment, both beams 1,8 with and without grooves may be
employed.
As a ceiling, it may be of interest to employ wood wool panels. Wood
wool panels absorb sound efficiently and transmit little sound compared
with, for example, a plaster board.
The form of the flooring structure may be varied in many different ways
without deviating from the inventive concept as herein disclosed. How-
ever, it is always important to ensure that, when one or more adjacent
beams 1 are subjected to a dynamic loading, the transfer of the loading
movement of the beam/beams to other beams in the flooring structure is
minimized.
While the present invention shows and is described in connection with
wooden flooring structures, a person skilled in the art will perceive

CA 02360565 2001-07-13
WO 00/42266 PCT/SE00/00037
6
that the same principle may be employed for flooring structures of
other materials, such as, for example, concrete and steel.

Representative Drawing