Two-layer cavity floor covering

A two-layer cavity floor construction comprising a base layer of profile element panels with a plurality of passage-forming spacer elements and a surface layer which combine to provide a minimal overall height with particularly good noise and footstep insulation. The base layer is formed from a noise-insulating material preferably based on polyurethane bound in a polyurethane foam.

BACKGROUND OF THE INVENTION 
1. Field of the Invention: 
The invention relates to a two-layer cavity floor covering comprising a 
base layer having spacer elements, a cover layer and a rim binding for 
attachment to a wall surface. 
Recent floor constructions which make it possible to install supply lines 
such a electrical cables, telecommunications, electronic data processing 
networks, ventilation, cooling and also heating systems under the actual 
floor surface have become prevalent to an ever greater extent in office 
buildings and the like. Such floor constructions are generally designated 
as cavity or double floor constructions. The advantage of these floor 
constructions compared with conventional floors lies in that, particularly 
in the case of subsequently required modifications, such as regrouping of 
working spaces in large office areas or in the case of supply line 
defects, a direct access to the supply lines in the floor system is 
possible where required without great effort or cost. 
2. Discussion of Related Art: 
It is known for this purpose to use two-part floor constructions comprising 
a carrier layer and a cover layer, which are formed of spacer elements. In 
such case, industrially prefabricated carrier plate systems having useful 
floor coverings are installed in situ on individual telescopic stands 
fastened on the floor and serve as spacer elements. The installation of 
these individual telescopic stands is very expensive since each element 
must be fastened separately at the floor surface. The versatility of their 
fabrication is limited since not all the floor coverings can be 
prefabricated industrially. In addition, the sound and heat insulation 
properties of such a system are not satisfactory. 
It is also known to install casing elements made of synthetic material or 
metal and to subsequently pour a liquid polish based on anhydrite onto 
these elements. The appreciable installation height of about 15 
centimeters, which in most cases excludes a subsequent installation during 
a refurbishing operation, and the long drying time of the floor polish 
requiring about 28 days are disadvantageous in such a system. 
Two-layer floor coverings are further known from German Utility Model 80/24 
008 in the heating, ventilation and air-conditioning field. The carrier 
layer therein consists of individual spacer elements which must be 
fastened separately on a floor surface, and a cover layer of example of 
wood plates or the like is provided thereon particularly in the case of 
the refurbishing of old buildings. The assembly of the carrier layers, 
constructed as individual elements for the cover layer, is very expensive. 
Further, inadequate footstep sound reduction is provided by this floor 
covering. 
A cavity floor construction of the type herein is known from Gemman patent 
application 32 01 085. In addition to a base layer and a surface layer, 
this known cavity floor construction comprises a sound-insulating layer of 
foam, fiber mats or the like arranged on the subfloor and also a 
pressure-distributing layer. Although this floor construction, which 
comprises a total of four layers, is distinguished by relatively good 
noise insulation, it is unsuitable in many cases, particularly for 
subsequent installation in a renovation program, on account of its 
considerable overall height. 
Another version of a cavity floor construction of the type herein is known 
from German patent application 33 28 792. In this floor covering, the base 
layer is oppositely arranged, i.e. the spacer elements are directed 
towards the subfloor surface while the surface layer lies on the 
continuous surface of the base layer. The surface layer may consist of 
plastic screwed, wood, concrete or the like. It is possible in this way to 
level out any uneveness in the floor by forming the surface layer 
accordingly. However, the disadvantage of this cavity floor covering is 
that there is no insulation of noise or footstep sounds, which is 
particularly necessary in rooms accommodating sensitive electronic 
equipment. 
Thus, an object of the present invention is to provide a two-layer cavity 
floor construction which combines minimal overall height with particularly 
good noise and footstep insulation. 
Another object of this invention is the provision of a two-layer cavity 
floor covering which enables a simplified assembly and provides a 
substantial footstep sound reducing effect. 
DESCRIPTION OF THE INVENTION 
Other than in the operating examples, or where otherwise indicated, all 
numbers expressing quantities of ingredients or reaction conditions used 
herein are to be understood as modified in all instances by the term 
"about". 
The afore-mentioned objects are attained in accordance with this invention 
by providing a two-layer cavity floor covering wherein the base layer 
comprises a profile element panel having a plurality of spacer elements 
which form channels therein, and a cover layer thereover. The cavity floor 
covering construction is of the type wherein the base layer is formed from 
a noise-insulating material containing polyurethane bound in a 
polyurethane foam. 
A cavity floor covering constructed in this way is distinguished by 
particularly good noise and footstep insulation, so that it is 
particularly suitable for use in rooms where noise-sensitive equipment, 
such as electronic machinery, is accommodated. At the same time, the 
cavity floor construction is also distinguished by its particularly low 
overall height because no other noise insulating layers are necessary. The 
cavity floor construction according to the invention is thus suitable not 
only for installation in new buildings, but also and in particular for 
renovation programs where in most cases only limited installation space is 
available. 
According to the invention, different noise-insulating materials may be 
used for the base layer according to the special in-use conditions. Thus, 
the noise-insulating material may consist of polyurethane and mineral 
aggregate or expanded clay bound in a polyurethane foam or of polyurethane 
and rubber bound in a polyurethane foam. 
The noise-insulating material may also consist of polyurethane and an 
organic recycled material or a porous material bound in a polyurethane 
foam, the porous material preferably consisting of expanded clay. 
In one preferred embodiment of the invention, the panel-like surface layer 
lying on the spacer elements of the profile element panels comprises 
sawdust, cement or an acrylate dispersion as a constituent. This 
embodiment is particularly suitable for level subfloors where no 
differences in height in the subfloor surface have to be corrected. In 
this case, the surface or cover layer formed in accordance with the 
invention, in combination with the prescribed profile element panels, 
leads to particularly high noise and footstep insulation. 
Another particularly practical embodiment of the invention is distinguished 
by the fact that the surface layer lying on the profile element panels 
with spacer elements directed towards the surface of the subfloor is in 
the form of a quick-drying screed. This embodiment is particularly 
suitable for uneven subfloors because the uneven areas can be leveled out 
by the surface layer. The quick-drying screed requires a particularly 
short drying time of at most only two days, so that considerable time can 
be saved compared with normal floors where the secedes take about 30 days 
to dry. Particularly good noise and footstep insulation can be obtained by 
corresponding additives in the quick-drying scored in conjunction with the 
particular noise-insulating base layer. 
To this end, the cavity floor construction according to the invention is 
characterized, for example, in that the quick-drying screed comprises 
alumina cement, gypsum and organic additives and also aggregates as 
constituents. 
In a further embodiment, the invention provides that the rim binding is 
formed of rim elements which are straight-faced at the wall face and the 
lower edge of which rests on the floor, or the rim biding is formed of rim 
elements which are provided with a bearing shoulder for support at the 
upper edge of the cover layer and the lower edge of which provides a 
spacing from the floor of the floor covering. Both these different rim 
elements serve as terminating profiles for the cavity floor covering 
according to the invention. Depending upon the type of application of the 
floor covering, the use of the one or the other rim element is 
particularly suitable.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 illustrates a profile element panel 1 having a plurality of spacer 
elements 3 forming passages or channels 2 in accordance with this 
invention. The spacer elements 3, which are arranged uniformly on the 
profile element panel 1, are constructed as upwardly tapering truncated 
pyramidal structures. Accordingly, the cross-section area of the passages 
2 increases in an upward direction. The ratio of the height of the spacer 
elements 3 to that of the base height of the profile element panel 1 is 
about 3:1. 
The complete structure of a two-layer cavity floor covering is shown in 
FIG. 2. A surface or cover layer 4 with a floor covering 5 is laid on the 
spacer element 3. The edging along a wall surface 6 is formed by a 
straight-faced boundary element 7 with a groove 8 which is used to 
accommodate the boundary edge of the floor covering 5. 
An alternative form of edging of the cavity floor construction is shown in 
FIG. 3. In this case, the edging is formed by a boundary element 9 with a 
contact or bearing shoulder 10. 
The cavity floor construction according to the invention is installed in 
the following manner. After cutting to size, the individual profile 
element panels 1 are laid on a floor surface (not shown) in an existing 
building or new building. All supply lines (not shown in the drawing) may 
be laid in any desired direction in the plurality of passages 2 of the 
profile element panels 1. After the supply lines have been installed, the 
surface layer 4 correspondingly cut to size is laid on the spacer elements 
3 of the profile element panels 1. If desired, the surface layer 4 may be 
bonded or glued to the profile element panels 1. 
The illustrated floor covering may have the following exemplary dimensions. 
The height of the profile element panel 1 may be about 15 millimeters, 
that of the spacer elements 3 may be about 45 millimeters, and that of the 
surface layer 4 may be about 22 millimeters. Altogether, an overall height 
of only about 85 millimeters thus results, subject to consideration of the 
floor covering 5. Thus, this floor covering structure is suitable 
particularly for use in the refurbishing field. 
The straight-faced boundary element shown in FIG. 2 represents one possible 
form of edging. The boundary element 7 may be fixed to the wall surface 6 
before the actual floor construction is installed. The bottom edge of the 
boundary element 7 rests on the surface of the floor. The groove 8 in he 
boundary element 7 accommodates the edge of the floor covering 5 on the 
surface layer 4. 
Alternatively, it is possible to use the boundary element 9 shown in FIG. 3 
with the contact or bearing shoulder 10 which is fitted after installation 
of the cavity floor construction. It rests through the shoulder 10 on the 
floor covering 5 and hence on the surface layer 4. The shoulder 10 also 
serves as a finishing edge or skirting board. The lower end of the 
boundary element 9 remains at a distance from the floor or from the bottom 
of the profile element panel 1. 
The profile element panel 1 and also the boundary elements 7 and 9 consist 
of a noise-insulating material preferably based on polyurethane bound in a 
polyurethane foam. The noise-insulating material may consist of 
polyurethane and mineral aggregate or expanded clay, of polyurethane and 
rubber or even of polyurethane and an inorganic recycled material or a 
porous material. These materials of the two-layer cavity floor 
construction lead to extremely high noise and footstep insulation without 
any need for additional base layers, providing for a minimal overall 
height. The surface layer 4 advantageously consists of sawdust, cement and 
an acrylate dispersion. 
Another embodiment of the invention is shown in FIGS. 4 and 5. Compared 
with the embodiment shown in FIGS. 1 to 3, the profile element panel 11 
are oppositely arranged, i.e. with the spacer elements 12 lying face down 
on a subfloor 13. A sheet or film 15 of plastic or the like is placed on 
the surface 14 of the profile element panels 11 and is covered by a 
surface layer 16. The surface layer 16 is preferably formed by a 
quick-drying screed applied after laying of the profile element panels 11 
and the film 14 which is used for sealing. Any uneven areas in the 
subfloor 13 can be levelled off by this layer of screed. This embodiment 
of the floor construction is also distinguished by particularly good noise 
and footstep insulation, the profile element panels 11 again being formed 
from the noise-insulating materials mentioned above, in addition to which 
the screed may contain corresponding noise-insulating additives. 
FIG. 4 show one possible embodiment of a joint at the junction between two 
profile element panels 11. The profile element panels 11 have not been 
specially finished, but abut one another with free shoulders 17. To ensure 
the stability of the floor construction in this region, a reinforcement 18 
is provided in the plastic screed 16. 
As shown in FIG. 5, there is no need for this reinforcement providing the 
profile element panels 11 are cut off at their edges in such a way that 
the spacer elements 12 abut one another at their adjoining edges. 
The invention is of course not confined to the embodiments shown by way of 
example in the accompanying drawings. Other embodiments are possible 
without departing from the basic concept of the invention. Thus, it is 
also possible to use profile element panels of other noise-insulating 
materials. However, the essential feature is that no additional 
noise-insulating layers are necessary, guaranteeing the minimal overall 
height of the floor construction.