Note: Descriptions are shown in the official language in which they were submitted.
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'rhis invention relates to a rnethod of attaching or
installing,in the construction of a wall or floor, an upper or
~' outer thin veneer facing of frangible cementitious material~ such as, for example, terrazzo topping, onto a sub-surface of
:i concrete.
A common method of making a terrazzo floor comprises
3 applying a two-inch mortar underbed to a structural concrete ;~
~3
slab and a layer of terrazzo topping of about one-half inch
thickness onto the mortar underbed. However, the resulting
concrete structural slab sub-surface tends to crack or move due
to the presence of moisture and due to temperature changes, and
;~ to other causes which may include stresses, rupture or settling and,
in that the terrazzo topping is intimately bonded to the
sub-surface by the mortar underbed, cracking or movement of the
r. ~
: concrete sub-surface causes corresponding cracking of -the
terrazzo top~ing.
This lnvention precludes the need for the mortar under~
~ ~ bed normally required and provides a novel composite structure
:9 ~ which substantially obviates cracking in the frangible upper or
~20 ~ outer thin veneer facing due to fracture, cracking or other ;
movement of the underlying sub-surface.
In accord with this invention, a pre-manufactured
intermediate sheet,which is impermeable to liquid, is attached
~ by an elastomeric adhesive to the sub-surface and bonded to the
`j frangible upper or outer thin veneer facing. The adhesive may ~
be of any type which, in its function of holding the intermediate
sheet to the sub-surface, will, through elasticity or flow,
permit movement of the sub-surface laterally without;transmitting `~
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the stresses due to movement through the Iiquid impermeable
~30 sheet, and may comprise a siDgle layer or composite layer. ;~
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~ n more ~etail, the com~osite structure of the
invention comprises, in comblna-tion, a concrete sub-surface, a
sheet of flexible pre-manufactured liquid impermeable material,
means for adhesively securing said sheet to said concrete sub~
surface, a frangible thin veneer facing of cementitious material,
and means for bonding said veneer facing to said liquid :~
impermeable sheet, said bonding means including a bonding agent
compatible with said sheet material and with said facing veneer ~ ~-
which is applied in the form of a wet slurry mix, and said
adhesive means permitting lateral movement of said concrete sub~
surface relative to said thin facing veneer. ~-
The method of applying the said structure comprises~
causing adherence of a pre-manufactured liquid impermeable sheet
to a concrete sub-surface by an adhesive and applying said
frangible veneer thereover while in a wet slurry state and
bonding said frangible veneer to said liquid impermeable sheet
through a bonding agent compatible with said impermeable sheet
and facing veneer, wherein the adhesive is selected so that said
adhesive will allow lateral movemen* of said concrete sub- .
surface relative to said thin frangible veneer.
The liquid-impermeable sheet adhering to the concrete
sub-floor is bonded through a bonding agent to a terrazzo or the
like topping poured, placed or otherwise installed thereover.
There is thus produced a construction wherein a terrazzo floor ~; -
may be produced appearing similar to those produced previously,
but is substantially reduced in thickness, and wherein the
lateral movement of the concrete sub-floor, due to cracking or
otherwise, is absorbed by the elastomeric adhesive joining the
concrete sub-floor to the liquid-impermeable sheet, and cracking `
of the terrazzo is thus prevented since the concrete sub-surface
and terrazzo topping are not rigidly bonded together. The
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invention is not conflned to appllcation -to a horizont~l
~` surface but may also be used with vertical surfaces for
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attaching a terrazzo veneer to a concrete sub-wall. Similarly,
~-~ the invention is equally applicable where the outer wall or
floor surface is not terrazzo, but includes, and the term
"terrazzo" is intended to include, such equally frangible
cementitious outer layers applied as wet slurry mixes such as
, new concrete, stucco and portland cement and sand mixes attached
~ .
ij to the sub-floor or sub-wall. The sub-surface normally is
~; 10 concrete but can be formed of masonry.
In drawings which illustrate preferred embodiments of
the invention:
~ Figure 1 shows a perspective view, partly cut awayl .
i~ of a floor construction in accord with the ~ `
, invention; and
Figure 2 shows a cross-section of a second embodiment
~? of the floor construction of the invention.
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. Figure 1 of the drawings, which shows a preferred
il embodiment of the invention, illustrates a small section of
~ 20 concrete sub-floor 10 with the adhesive layer 20 attaching the
;~ intermediate sheet 30 thereto. The intermediate sheet is ln
~ i turn bonded to the upper or outer layer of terrazzo veneer 50
;i, by bonding agent 40 which, as illustrated, penetrates the upper
portion of the intermediate sheet 30 and the adjacent depths of
:~ the terrazzo.
The concrete sub-surface, as previously explained, may ~-
be concrete sub-floor or may be a concrete or masonry sub-wall,
' ~ it being noted that in such arrangements the terrazzo 50
~;1 conventionally is trowelled or rolled on over the bonding agent ;~
~-~ 30 40. The concrete sub-wall and the inventive construction may,
of course, be an exterior or interior installation.
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The li(3uid-impermeable sheet can be an organic polymer
such as polyethylene, polypropylene or polyvinyl chloride, an :
elastomer such as a copolyrner of styrene-butadiene, reinforced
-~ with glass fibre, if desired, or a canvas f.abric such as ; ;
Egyptian cotton.
A number of alternatives exist for the methods o~
~ achieving adhesion between the said liquid-~impermeable sheet and
s the underlying sub-surface on the one handl and bonding between , ~
the liquid-impermeable sheet and frangible thin terrazzo facing ~.
on the other hand. ``~
In one alternative, the liquid-impermeable sheet formed .
y of polyvinyl chloride may be provided with a fabric or porous
layer on one or both sides thereof. The fabric or porous layer :~
attached to the liquid-irnpermeable sheet is adapted, through
~ its pores or interstices, to receive an adhesive or a bonding
:~ agent to attach the liquid-impermeable sheet to an adjac:ent layer.
The fabric or porous layer on each side will preferably be attach-~
. ~
ed by being partially embedded in the liquid-impermeable layer
~ : material during its manufacture rather than merely attached there~
:.~0 to by adhesive.
Examples of fabric layers which have been found suitable,
both with the bonding agent fo:r the terrazzo topping, or equiva- .
lent, on one side of the liquid-impermeable sheet, and w.ith the
adhesive for the concrete sub-layer, on the other side of the
liquid-impermeable sheet, include: burlap, driil, jérsey and
sateen. Canvas fabric is suitable as a liquid-1mpermeable sheet
and its fabric texture provides good adhesion between the sheet
and underlying adhesive or overlying bonding agent. ~:
The fabric~layer may be dispensed with on the side of
the liquid-impermeable sheet facing the concrete sub-suriface : ~
with the use of suitable adhesive pre-applied during manufacture .
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of the liquid-impermeable sheet, tc, be descrlbed, but is
required when the adhcsive is applied to the sub-surface at
the time of installation.
The adhesive for attaching the intermediate layer to
the concrete sub-surface can be applied to the concrete after
the latter is cured. The adhesive layer, of up to about
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1/4 inch and preferably about 1~16 to 1/8 inch thickness, may
be of any suitable type of material and thickness which will
~: stretch over limited areas to allow the concrete sub-surface to
move laterally relative to the terrazzo topping or other super-
imposed layer under shifting or cracking of the concrete sub~
floor. A suitable adhesive is sold under the trade mark ~;
~ "Flintlastic 790-11" and manufactured by the Flintkote Company
I of Canada Limited of 30th Street, New Toronto, Ontario, Canada.
Where the adhesive is to be pre-applied during manu-
facture of the layer, a suitable liquid impermeable sheet is that
sold undér the trade mark "BITHUTHENE" manufactured by Grace
Construction Product, 66 Haymus Road, Scarborough, Ontario~, Canada.
This product is a high-density,~cross-laminated polyethylene or
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polypropylene sheet of about 4 mils. thickness with a pre-applied~
adhesive of rubberized asphalt of about 1/16 inch thickness on
one side thereof.
A filler such as fine sand or lightweight aggregate
such as expanded clay, shale ~sold under the trade mark "HAYDITE"
manufactured by Domtar Construction Materials Limlted) or slag
; can be~incorporated in the rubberized asphalt in an amoun~t of
~ not more than about 2:1 by weight filler to rubberlzed~asphalt.
-~ ~ ~ Figure 2 illustrates another embodiment of my invention
in which the adhe~sive means comprise a composite layer desig- ;~
~ 30 nated by the number 60 having a first rel-atively thin adhesive
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layer 62 of, for c~xample, "Flintkote Fast-Set-Brush-On Cement'l,
a trade mark of Flint};ote Company of Canada Limited, adapted to
adhere an organic sheet 66 of polyethylene, polypropylene or
polyvinyl chloride of about 8 mils. thickness -to concrete sub-
- floor 64 and a second adhesive layer 68 of rubberized asphalt of
.
about 1/16 inch thickness adhered to the upper surface of sheet
/, 66 and adapted to adhere to intermediate liquid-impermeable sheet
i 70. sonding agent 71 attaches terrazzo veneer 72 to sheet 70.
Adhesive layer 68 provides an effective slip plane between
concrete sub-surface 64 and terrazzo veneer 72. Sheet 66 can
l also be formed of a textured fabric such as canvas, burlap, drill, '
;~ jersey or sateen.
The bonding agent 40, 71 may be any type which will
attach to the liquid impermeable làyer and/or fabric layer, and to
the terrazzo topping. Suitable bonding agents lnclude a~ueous ~
resinous latex emulsion such as "Weldbond" sold by Frank T. Ross ;`
& Sons (1962) Limited, P.O. Box 248, ~lest Hill Post Office, ;
Ontario, Canada; "Weldcrete" referred to hereafter; and epoxy -~
, resins.
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,~ 20 The bonding agent can be applied to the intermediate
sheet shortly before pouring of the terrazzo topping or pre~
applied before laying of the intermediate sheet. If applied to
an installed sheet, the bonding agent normally is permitted to ~;
~, set or cure for a time sufficient to allow the bondlng agent to
become tacky.
When the bonding agent is pre-applied to the liquid-
impermeable sheet, the bonding agent can be pre-wetted with
water before the terrazzo is applied or wetted by the water of
the terrazzo slurry mix. For pre-application of the bonding -
; 30 agent during manufacture of the sheet I prefer to use "WeldcIete", -
~a product of Larsen Products Corp., 5420 Randolph Rd., Rockville,
r
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~aryland, 20852, U.S.A. This product is applied wet to one side
of the liquid imperrneable sheet during its rnanufacture and
allowed to dry. It then remains inactive until the time of use.
The teIrazzo topping is poured onto the bonding agen-t as a wet
slurry mix to form a 5/~ inch thin veneer facing, permitting
permeation of the bonding agent into the acljacent depths of the
terrazzo topping. When the topping thus attached by the bonding -
agent has been smoothed by trowelling or the like, it may be
finished in accord with conventional techniques. ~;
The liquid-impermeable sheet, if selected from an
organic material such as polyethylene, polypropylene or poly-
` vinyl chloride, preferably is abraded by buffing to roughen the
surface texture of the side to be bonded to the facing veneer.
I have found wet or dry buffing with #400 silicon carbide sand-
' paper or #200 garnet sandpaper satisfactory.
In addition to buffing of the surface of the liquid-
impermeable sheet, contact cements such as known by the trade
mark "Wall Strap", manufactured by LePages Limited, 50 l~est Drive,
Bramalea, Ontario, can be applied to the liquid-impermeable sheet
in concentrated or diluted form by rolling, brushing or spraying,
to a thickness of up to about 4 mils., during premanufacture to
, provide a further roughened surface texture. The sheet of poly-
ethylene with a layer of applied contact cernent, or example, can
be heated to the softening temperature of the sheet to fuse the
contact cement to the sheet.
, A clay filler such as one of portland cement, silica or
limestone dust, or combination thereof, added to the contact
cement in an amount of about 2% by weight, can be added to improve
i drying of the contact cement and to increase the roughness of
surface texture of the intermediate sheet.
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rhe pre~sent invention provides a numher of important
-~ advantages. A thin floor faciny veneer of terrazzo or the like
cementitious frangible material, applied over a sub-floor such
~ as concrete or masonry wall, can be provided which has the ~
; outward physical characteristics of a conventional terrazzo ~ ;
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~ floor, but with a reduction of floor thickness of about two
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inches by obviating the need for a mortar underbed, and wherein
should the concrete sub-floor or masonry wall crack or shift, no
corresponding fracture or cracking takes place in the terrazzo
topping due to the presence of the rubberized asphalt layer. It
; is noted that bonding of the facing veneer to the sub-floor or
sub-wall through the medium of the intermediate sheet simulates
~ the monolithic terrazzo mass of a conventional terrazzo floor `
1 required to prevent "bounce'l or reverberation oE the superimposed
layer, which could otherwise result in separation of the acing
from the sub-surface due to the light weight of the terrazzo. In
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~;i addition, the liquid impermeable sheet seals and isolates the ~ ~
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~ solvents present in the rubberized asphalt layer from the
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' ~J terrazzo facing veneer to prevent discoloration of the veneer.
3 20 It will be understood, of course, that modifications
can be made in the preferred embodiment of the present invention
as described hereinabove without departing from the scope and `~
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~ purview of the appended claims. ~
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