GB2437370A

GB2437370A - Floor for wet area

Info

Publication number: GB2437370A
Application number: GB0607965A
Authority: GB
Inventors: Brian Bentley
Original assignee: BRIK CONTRACTING Ltd
Current assignee: BRIK CONTRACTING Ltd
Priority date: 2006-04-21
Filing date: 2006-04-21
Publication date: 2007-10-24
Anticipated expiration: 2026-04-21
Also published as: GB2437370B; GB0607965D0

Abstract

A sub-floor of a building, typically for a wet area, comprising a plurality of adjacent sections comprising a lowermost layer of substantially rigid foamed plastics material (12) and a glass fibre net (13) above the lowermost layer. Each joint is covered with a cementitious layer (14) on and through the net, a glass fibre and resin layer (15, 16), and a layer of dry aggregate. Preformed sections may define a slope for water drainage and suitable drainage channels (21). The sub-floor typically supports floor tiles (18) in use.

Description

1 2437370 Sub-Floor and Method of Constructing a Sub-Floor This

invention relates to sub-floors of buildings, and particularly to sub-floors for wet rooms.

Wet rooms, such as shower rooms, require a waterproof floor in order to prevent structural damage and deterioration of a building. Leaking floors above ground floor level are a particular problem. Large wet rooms of multi-user buildings are generally troublesome for a variety of structural and constructional reasons, and frequently loose or damaged floor tiles cause additional difficulties.

A typical wet room floor of a multi-user building comprises a concrete raft on which a sand and cement screed is laid to create shallow slopes (fall) leading to drainage channels. The screed may be up to 100 mm thick. The surface of the screed is overlaid by floor tiles, and the gaps between these tiles are grouted. Problems arise because grout is not wholly waterproof, and there are difficulties in obtaining an adequate water seal at the drainage points. Often water will enter the screed volume, and cause deterioration thereof, along with tile loosening and structural damage.

Water leakage through the sub-floor may be prevented by tanking with impervious materials such as bitumen or glass fibre reinforced resin. However water tends to collect on these layers, and this may also result in tile loosening because of poor adhesion of bonding materials.

One particular problem with glass fibre reinforced resin is that the resin may permeate downwardly and damage lower sub-floor layers. Hot bitumen may also be deleterious to sub-floor layers, particularly at first floor level.

What is required is a sub-floor which overcomes these problems, is quickly and inexpensively installed, and can retain floor tiles with very good adhesion. Such a sub-floor should be capable of accommodating building movement, and have good insulation properties.

According to the invention there is provided a sub-floor of a building comprising a plurality of adjacent sub-floor sections each comprising a lowermost layer of substantially rigid foamed plastics material, and a glass fibre net above the lowermost layer, each joint between adjacent sections being covered with a relatively thin layer comprising a cementitious material on and through said net, said cementitious material being covered with glass fibre textile and glass fibre resin and layer of dry aggregate being provided on said resin.

Such a sub-floor provides a waterproof base for floor tiles fixed by a tile adhesive. The dry aggregate layer ensures very good tile adhesion in the vicinity of the junction between adjacent sub-floor sections, whilst the polystyrene layer provides insulation and a degree of compliance. The layer of cementitious material prevents resin from permeating into the foamed plastics material where it may weaken or damage the structure thereof.

A sub-floor according to the invention is typically laid upon a concrete raft, being the lowermost layer of the floor. The glass fibre net is preferably attached to the lowermost layer of each section to form an unitary component.

The foamed plastics material is preferably rigid, most preferably of expanded polystyrene layer, and may be conveniently shaped prior to installation to give the required fall'. A sub-floor according to the invention may be easily formed of a plurality of sections and installed rapidly since there is no need to wait for a conventional screed to harden. Sub-floor sections may be pre-cut and delivered to site with all necessary vents and channels, so as to permit rapid installation, and construction of a floor.

The expanded foam layer may for example include a channel formed in the upper surface thereof and adapted to receive a drainage tray. Preferably said tray is formed of cured glass fibre reinforced resin so as to overlie the glass fibre net, and optionally to be bonded thereto. The tray and expanded foam layer may be supplied as an integral assembly.

In a preferred embodiment, the sub-floor includes one or more such trays, wherein each tray side wall includes a substantially horizontal flange to overlie said net, and a continuous upstand to provide an edge reinforcement for floor tiles laid on the sub-floor. The horizontal flange(s) may be overlaid by a cementitious layer after positioning of the tray(s).

The expanded foam layer may include a glass fibre net on the underside, for protection and to better preserve structural integrity of the polystyrene material.

The cementitious layer may be any appropriate mix containing sand and cement, or may be a pre-mixed mortar. The layer is preferably laid as a slurry which is allowed to solidify before application of the glass fibre and resin layer.

According to a second aspect of the invention, there is provided a method of constructing a sub-floor of a building, and comprising the steps of: placing a sub-floor section on a foundation adjacently to an upright abutment surface, the lowermost layer of said section consisting of substantially rigid foamed plastics material having a glass fibre net thereon; laying cementitious material on and through the net and across the junction with said abutment surface; laying a resin bonded glass fibre layer on said cementitious material; and laying a dry aggregate over said glass fibre layer.

The method may comprise laying the cementitious layer across a junction between two adjacent sub-floor sections, or between a sub-floor section and an adjacent wall.

Preferably the method further includes the step of completing the floor by: laying a tile adhesive onto the upper surface of said sub-floor, laying tiles onto said adhesive, and grouting said tiles.

The method may further include the step of preforming said sub-floor by forming sub-floor sections substantially of expanded polystyrene, and adapting said sections for side to side abutment.

The method may further include the step of forming or shaping the surface of said sections to define a fall, andlor to define one or more drainage channels.

Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only in the accompanying drawings in which: Fig. 1 is a transverse section through a floor incorporating a sub-floor in accordance with the invention.

Fig. 2 is a transverse section through a sub-floor incorporating a drainage channel.

With reference to Fig. 1, a concrete foundation 10 has a coat of adhesive 11 laid thereon for fixing lowermost sub-floor components A,B, each comprising a layer of polystyrene 12 having upper and lower layers of glass fibre net 13. The glass fibre net improves bonding of the upper and lower surfaces and protects the polystyrene material.

Overlaying the upper glass fibre net in the region of the junction is a layer of cementitious material 14 which may also enter into the gap (if any) between the sections A,B. A layer of glass fibre 15 is laid over the cementitious layer, and is bonded thereon with a suitable curable resin 16; the resin lies only upon the cementitious layer, which acts as a barrier to downwards permeation thereof. A layer of fine dry aggregate (not shown), such as kiln dried sand, is sprinkled upon the resin to complete the sub-floor.

Typically the sub-floor 12-16 has laid thereon a layer of tile adhesive 17 on which are bedded floor tiles 18 with grout 19 therebetween.

The polystyrene layer 12 provides a convenient means of allowing a slope or fall for the drainage of water. It also provides insulation, and can accommodate any imperfections in the surface of the foundation. The foundation 10 may of course be of other materials than concrete, for example block and beam, and the precise nature thereof is not important provided that it is structurally sound.

The polystyrene layer 12 is typically between 40 m and 100 mm in thickness. The glass fibre net 13 is around 3 mm thick. The slurry layer 14 is thin, and just sufficient to cover the glass fibre net; typically 4-6 mm. The aggregate layer is of negligible thickness, being a single particle thickness of say 1-2 mm; this layer is provided to blind the resin and provide adhesion to the tile adhesive 17, and may be scattered by hand.

The dimensions of the components and layers illustrated in Fig. 1 are illustrative, and somewhat exaggerated in order to better show the features.

Fig. 2 shows a drainage channel 21 inset in the polystyrene lower layer 12. Certain features are exaggerated, and certain other layers of Fig. 1 are omitted so as to improve clarity.

The channel 21 is of glass fibre and overlies the upper glass fibre net 13 by means of continuous longitudinal flanges 22. Suitable upstands 23 extend along each edge to provide an abutment face for floor tiles; the eventual floor level is indicated by chain-dot line 24. A suitable drainage grid 25, e.g. of stainless steel, lies in the top of the channel on opposite shoulders 26 just inboard of the upstands 23.

The flanges 22 and net 13 are covered with a cementitious layer 27 and may further be covered with glass fibre reinforced resin 28 followed by a sprinkling of dry aggregate.

The sub-floor and construction method of the invention permit rapid construction by the use of prefabricated components which incorporate a drainage slope without the need for a screed thereon. The cementitous layer provides a suitable means of smoothing the joints between adjacent sub-floor sections, whilst providing an impenetrable barrier to glass fibre resin laid thereon. The aggregate layer ensures very good adhesion of the usual floor tiles.

It will be observed that the construction and method uses preformed components and cold' materials which are selected for relatively rapid curing. Both the cementitious layer and the glass fibre resin are laid in a fluid form, but rapidly solidify, so that forming of the sub-floor can proceed rapidly. Furthermore there is no delay in laying the final floor surface of e.g. tiles.

It will also be appreciated that the cementitious layer can be used to bridge junctions of the lower layer with a building side wall or internal wall, so as to permit application of glass reinforced resin and dry aggregate. Such an arrangement improves tile bonding at all such horizontal/vertical interfaces.

Claims

Claims 1. A sub-floor of a building comprising a plurality of adjacent

sub-floor sections each comprising a lowermost layer of substantially rigid foamed plastics material, and a glass fibre net above the lowermost layer, each joint between adjacent sections being covered with a relatively thin layer comprising a cementitious material on and through said net, said cementitious material being covered with glass fibre textile and glass fibre resin, and layer of dry aggregate being provided on said resin.

2. A sub-floor according to Claim 1 and further including a concrete raft as base.

3. A sub-floor according to Claim 1 or Claim 2 wherein said glass fibre net is :..::: attached to the lowermost layer of each said section to form an unitary * SII component. S...

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4. A sub-floor according to any preceding Claim wherein said foamed plastics material is an expanded polystyrene layer. S.SS * I

* SI S. S * 20 5. A sub-floor according to Claim 4 wherein said polystyrene layer defines a slope for drainage of water, in use.

6. A sub-floor according to Claim 4 or Claim 5 wherein said foamed plastics layer includes a channel formed in the upper surface thereof and adapted to receive a drainage tray.

7. A sub-floor according to Claim 6 and further including a drainage tray, said tray being formed of cured glass fibre reinforced resin so as to overlie the glass fibre net.

8. A sub-floor according to Claim 7 wherein said tray and foamed plastic layer comprise a bonded assembly.

9. A sub-floor according to Claim 7 or Claim 8 and comprising a plurality of said trays, each tray side wall including a substantially horizontal flange to overlie said net, and a continuous upstand to provide an edge reinforcement for floor tiles laid thereon.

10. A sub-floor according to any preceding claim wherein said foamed plastics layer includes a glass fibre net on the underside thereof and adapted to better preserve structural integrity of the foamed plastics layer.

11. A method of constructing a sub-floor of a building, and comprising the steps of: * placing a sub-floor section on a foundation adjacently to an upright abutment surface, the lowermost layer of said section consisting of substantially *S.

rigid foamed plastics material having a glass fibre net thereon; :r laying cementitious material on and through the net and across the junction *:. with said abutment surface; laying a resin bonded glass fibre layer on said cementitious material; and *.StSI * : laying a dry aggregate over said glass fibre layer.

*I*.SI * 20 12. A method according to Claim 11 and further comprising laying the cementitious layer across a junction between two adjacent sub-floor sections, or between a sub-floor section and an adjacent wall.

13. A method of Claim 12 and further including the steps of: laying a tile adhesive onto the upper surface of said sub-floor, laying tiles onto said adhesive, and grouting said tiles.

14. A method of any of Claims 11 to 13 and including the step of preforming said sub-floor by forming sub-floor sections substantially of expanded polystyrene, and adapting said sections for side to side abutment.

15. A method according to Claim 14 and further including the step of shaping the surface of said sections to define a fall.

16. A method according to Claim 14 or Claim 15 and further including the step of shaping the surfacc of said sections to define a drainage channel.

17. A sub-floor substantially as described herein with reference to the accompanying drawings.

* 18. A method of constructing a sub-floor of a building, substantially as described *** herein with reference to the accompanying drawings.

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