AU2005218056A1 - Underlay for removable tile flooring - Google Patents

Description

C05132 UNDERLAY FOR REMOVABLE TILE FLOORING Technical field C/ [01] This invention relates to an underlay for tiled floors. The invention is particularly Suseful with tiled floor installations where it may be desirable to remove and replace the tiles from time to time.

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SBackground art 00 [02] Tiled floors are frequently laid on a base floor such as a concrete floor. The tile Sadhesive is very strong and, when the tiles are to be removed, it is often the case that the concrete floor is damaged, resulting in the need for costly repair work. In addition, the removal is labour intensive, costly, noisy and creates dust.

[03] In laying tiles, the base must be sufficiently smooth to avoid cavities beneath the tile which may lead to cracking of the tiles in use. Thus, considerable effort is required to ensure the concrete base is sufficiently smooth, and a topping layer is often required to be laid for this purpose. This layer usually needs to be trowelled smooth, a task which requires considerable skill and experience. Once the surface has been prepared, the tile adhesive is applied and prepared with a notched trowel to ensure the tiles are level after laying.

[04] Schluter Systems, "http://www.schluter.com/english/products/2002/sectionf/ditra/60 1ditra.html#application", discloses a tile underlay consisting of an upper layer of polyethylene having square indentations 1/8 inch deep with dovetail side walls to key the tile adhesive. The underside is a fleece laminate. The fleece is glued to the base floor.

The purpose of the fleece is to absorb movement in the base floor and thus to uncouple this movement from the tiles. The gluing of the tiles to the floor again requires considerable restoration work when the tiles are to be removed.

The system also has the disadvantage of reducing the load carrying capacity by as much as 50% for point loads.

C05132 C [06] The applicant does not concede that the prior art described in this specification is Spart of the common general knowledge in the field.

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e¢ Disclosure of the invention.

[07] This invention provides an underlay for tiles which facilitates the removal of the 00 tiles, and a tiling system using the underlay.

[08] A first embodiment of the invention provides a tiling underlay having an upper ri surface or upper layer compatible with an adhesive suitable for tiles, and an under-surface or under-layer adapted to reduce or prevent adhesion between the underlay and a base floor on which the underlay is to be applied.

[09] The upper layer enhances the adhesion of the tile adhesive to the upper layer. In one embodiment, a special adhesive is formulated to enhance compatibility of the adhesive with the underlay and the tiles.

[010] Preferably, the underlay is flexible so as to permit it to be rolled for storage and transport and unrolled for use.

[011] The underlay also has sufficient dimensional stability and compressive strength to form a sufficiently stable underlay to permit tiles to be affixed to it.

[012] The upper surface of the underlay may have a rough surface.

[013] The upper surface may incorporate a particulate inclusion.

[014] The particulate can be adhered to the underlay.

[015] The underlay may be bitumen.

[016] The particulate maybe sand.

C05132 3 C [017] The substrate maybe flexible.

[018] The underlay may have a compression strength adequate to carry expected loads.

[019] The underlay in a preferred form includes a bituminous substrate with sand applied

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Sto its upper layer.

00 ,I [020] Preferably, the lower surface of the underlay is covered with a polyethylene layer.

The polyethylene layer makes it possible to roll the underlay for storage and transport, and I prevents adhesion between the underlay and the base floor. The base floor can be a concrete floor.

[021] In a preferred embodiment, the substrate is a laminate including a modified bitumen layer, an intermediate reinforcing layer and a second modified bitumen layer.

[022] The reinforcing layer can be formed of polyester and/or fibreglass.

[023] Tiles can be affixed to the underlay by an adhesive which is formulated for compatibility with the underlay.

[024] Preferably the tile adhesive includes a redispersible polymer.

[025] The redispersible polymer can be ethylene vinyl acetate.

[026] The invention also provides a method of laying the underlay wherein the underlay is laid in strips.

[027] Preferably, the strips are butt joined.

[028] The strips may be butt joined by staples.

C05132 [029] An angle member may be provided at the edges to retain the tiles and underlay in C place. The angle member can be of aluminium.

[030] A smoothing layer may be applied to the base floor before laying the underlay. The Ssmoothing layer may be a so called self-levelling layer.

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t [031] The invention can thus provide an un-bonded tiled floor which can be removed 00oO easily, substantially avoiding or reducing the problems of a bonded tiled floor system.

S[032] The lower surface of the underlay may have a co-efficient of friction in relation to the base floor which is sufficient so that the underlay will not slip in relation to the base floor under expected shear loads.

Brief description of the drawings [033] Figure 1 illustrates a portion of underlay according to an embodiment of the invention.

[034] Figure 2 shows the underlay and adhesive prepared for tile laying.

[035] Figure 3 shows a tile laid on the underlay.

[036] Figure 4 shows an embodiment of the invention adapted to accommodate a movement joint.

[037] Figure 5 shows an arrangement for terminating the tiles at an edge which is above an adjoining floor level.

Description of the invention [038] The invention will be described with reference to the drawings.

C05132 0 [039] The underlay is provided in rolls and rolled out in strips. The strips may be of the order of 2m wide. Preferably, the strips are 1 m wide. The strips may be left for several hours to allow "roll memory" to dissipate.

S[040] The underlay is flattened against the base floor to remove any voids between the underlay and the base floor.

00 [041] The strips are butt joined without overlap. Adjacent strips can be joined by stapling ,I at a suitable interval, every 300mm to prevent relative movement between strips. A maximum width of about 5m is preferred to limit thermal expansion. At the chosen limit, I metal angles are applied around the edges to reinforce the edges. Similarly, existing expansion joints and the edges around the perimeter of a room are finished with a metal angle.

[042] The underlay may be of the order of 0.7 mm up to 8mm thick. A preferred range is from 2mm to 3mm.

[043] Figure 1 is a schematic representation of a portion of an embodiment of a substrate suitable for use in the present invention.

[044] The underlay 100 is a flexible laminate. The underlay includes a number of laminae 101, 102, 103, 104.

[045] The upper layer 101 is an adhesive enhanced layer, in this case a modified bitumen layer with a particulate 105 adhered to its upper surface. Layer 102 is a second modified bitumen layer. Layer 103 is a reinforcing layer, and layer 102 is a separation layer. The reinforcing layer 103 may include fibre glass and polyester. The separation 102 layer may be polyethylene.

[046] While the reinforcing layer and the modified bitumen layers are shown as separate layers, the reinforcing may be of an open weave, and the two bitumen layers bitumen may be a single matrix in which the reinforcing is contained.

C05132 C [047] The attachment layer 105 is a particulate material, such as sand which has been C applied to the skin of the upper layer 101 during manufacture.

[048] The proportion of particulate and the size of the particulate in the upper layer 101 Cc are chosen to provide a sufficiently roughened surface to provide adhesive keying, or, in other words, good adhesion, for the tile adhesive to the attachment surface.

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00 [049] Figure 2 shows the underlay 100 with the tile adhesive 106 having been trowelled with a notch trowel to form a square profile in preparation for the laying of the tiles. The notch trowel is used to obtain a uniform depth of adhesive in a solid bed. Cavities under the tiles can form points of weakness.

[050] Figure 3 shows a tile 107 after it has been laid on the tile adhesive 106.

[051] Figure 4 shows how the invention is applied in the region of a pre-existing expansion gap in a concrete or similar floor.

[052] The concrete slabs 41, 42 are separated by a gap 43. The underlay 44 is laid up to the edge of each slab. An angle 40 is affixed along the edge of the underlay and held by the tile adhesive 48. The tile 47 is then placed in position. The height of the angle 40 is preferably such as to align with the top of the tile. A "plug" 45, in the form of a foam backing rod or preformed gasket is inserted into the gap, and a sealant 46 is applied. The angle gives added strength to the end row of tiles. The flexible sealant and backing rod allow for the movement of the concrete without overstressing the tiles or adhesive.

[053] Figure 5 shows a similar arrangement where it is necessary to terminate the tiling system at a height above the adjoining floor surface. Angle 54 is held to the underlay 53 by adhesive 52 and abuts the end of tile 51. The top of angle 54 should be level with the top of the tile to protect the tiles from impact load.

[054] A ramp 55 should be provided to mitigate the trip hazard. The ramp 55 may be of hard rubber.

C05132 [055] The angle 54 helps to strengthen the edge row.

S[056] The boundary where the tile edge meets the room perimeter should be with an angle, preferably of brass of anodised aluminium. This acts to isolate the tiling system, Cc strengthen the edge row and enables easy removal of the tiling system without affecting the perimeter wall unduly.

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00 [057] A flexible sealant can be inserted between the edge of the angle and the edge of the wall where a watertight seal is required to prevent water penetrating under the tile system.

I [058] For additional stability, the angle rod may be anchored to the wall or floor at a number of points by screws, rivets or other suitable fastening means.

[059] Once the tiles have been laid, grout may be applied once the adhesive has cured sufficiently. This will depend on the nature of the adhesive and may also depend on the humidity, temperature and suchlike conditions. A suitable curing period may be 24 hours.

[060] The tiled and grouted surface can be sealed to prevent water penetrating the tiles.

[061]" The invention also relates to a method of laying tiles using the underlay and a tile adhesive to adhere to the upper surface of the underlay.

[062] The characteristics of bitumen mean that the normal tile adhesives may not adhere well to bitumen. Thus it is necessary to use a modified tile adhesive.

[063] Tile adhesive usually consists of cement and graded sand. To make an adhesive suitable for application to a bituminous substrate, a further embodiment of the invention proposes the addition of an adhesive or adhesive modifier adapted to enhance adherence to the particular underlay, such as bitumen, and in particular, modified bitumen.

[064] The further additives may be added to the normal tile adhesive to ensure satisfactory adhesion to the underlay. In particular, a redispersible polymer may be used.

An example of a suitable redispersible polymer is ethylene vinyl acetate (EVA). EVA C05132 C forms an integral part of the cement hydration matrix and can improve adhesion, flexibility N, and/or water resistance. Other suitable additives include styrene acrylic or styrene Sbutadine rubber.

Cc [065] In a still further embodiment, a water retention agent is added to the tile adhesive.

t [066] The water retention agent can be a cellulosic ether.

00 I [067] Other methods of treating the upper surface of the underlay, such as impressing a suitable pattern or roughening the upper surface of the underlay, may be used to enhance the adhesion of the adhesive. For example, a profiled roller may be used to create miniature indentations. The roller may be heated to a temperature sufficient to cause small viscous extrusions of the underlay material to adhere to the spikes. This may be done before or after the underlay is laid, and before the adhesive is applied.

Technical applicability [068] The invention is applicable to the installation of tiles, and is of particular use where the tiles are to be subsequently removed. The tiles and underlay can be lifted from the surface without significant damage to the base floor.

[069] While the invention has been described with reference to particular embodiments, the person skilled in the art will recognise that various materials and components may be substituted for those described and the integers described may be combined in various configurations without departing from the inventive concept.

Claims (28)

1. A tiling underlay having an adhesive keyed upper surface or upper layer, and an under-surface or under-layer adapted to reduce or prevent adhesion between the underlay and a base floor on whichthe underlay is to be applied. S

2. An underlay as claimed in claim 1, wherein the underlay is sufficiently flexible to 00 permit it to be rolled for storage and transport and unrolled for use.

3. An underlay as claimed in claim 1 or claim 2, wherein the underlay has sufficient N, dimensional stability and compressive strength to form a sufficiently stable underlay to permit tiles to be affixed to it.

4. An underlay as claimed in any one of the preceding claims, wherein the upper surface of the underlay has a rough surface.

An underlay as claimed in any one of the preceding claims, wherein the upper surface includes a particulate.

6. An underlay as claimed in any one of the preceding claims, wherein the particulate is adhered to the underlay.

7. An underlay as claimed in any one of the preceding claims, wherein the underlay includes bitumen.

8. An underlay as claimed in any one of the preceding claims, wherein the particulate is sand.

9. An underlay as claimed in any one of the preceding claims, wherein the underlay is flexible. An underlay as claimed in any one of the preceding claims, wherein the underlay has a compression strength sufficient to support a predetermined load.

C05132 N.

11. An underlay as claimed in any one of the preceding claims, wherein the lower Ssurface of the substrate is covered with a polyethylene layer. c

12. An underlay as claimed in any one of the preceding claims, wherein the underlay is a laminate including a modified bitumen layer, an intermediate reinforcing layer and a \O second modified bitumen layer. 00

13. An underlay as claimed in any one of the preceding claims, wherein the reinforcing layer can be formed of polyester and fibreglass.

14. An underlay as claimed in any one of the preceding claims, wherein the under surface of the underlay has a coefficient of friction in relation to the base floor which is sufficient to prevent slippage between the underlay and the base floor for shear loads less than a predetermined value.

A method of fixing tiles to an underlay as claimed in any one of the preceding claims, wherein tiles are affixed to the underlay by an adhesive which is formulated for compatibility with the underlay.

16. A method as claimed in claim 15, wherein the tile adhesive includes a redispersible polymer.

17. A method as claimed in claim 16, wherein the redispersible polymer is ethylene vinyl acetate.

18. A method of laying an underlay as claimed in anyone of claims 15 to 17 wherein the underlay is laid in strips.

19. A method as claimed in claim 18, wherein the strips are butt joined. A method as claimed in claim 19, wherein the strips is butt joined by staples.

C05132 C

21. A method as claimed in any one of claims 15 to 20, wherein an angle member is ¢',Iprovided at the edges to retain the tiles and underlay in place.

22. A method as claimed in claim any one of claims 15 to 21, wherein a smoothing Cc layer is applied to the base floor before laying the underlay. INO S

23. A method as claimed in any one of claims 15 to 22, wherein a keying surface is oO applied to the underlay after it has been laid.

24. A method of roughening a planar surface of an extrudable material, the method ,I including the step of applying a spiked surface to the planar surface under pressure.

A method as claimed in claim 24 including heating the spikes to a temperature above the extrusion temperature of the extrudable material.

26. A tiled floor including an underlay as claimed in any one of claims 1 to

27. A tiled floor as claimed.in claim 26, including a perimeter support to retain the tiles at the edge of the floor.

28. A tiled floor as claimed in any one of claims 26 or 27, wherein the perimeter support is an angle piece. Dated this 30th day of September 2005 Ardex Australia Pty Ltd By their Patent Attorneys HALFORD CO