GB2118892A - Moulding panels for plaster cladding - Google Patents

Abstract

Plaster cladding suitable for walls or ceilings comprises a precast fibre reinforced panel (1) having a smooth and uniform exposed faced which is ready, for example, for painting. Fibre reinforcement may take the form of a coherent fibrous mat (2) or short, discrete fibres randomly dispersed in the panel (not shown). In both cases glass fibres are preferred. Processes for manufacturing such a panel (1) are described in which a fibrous mat (2) is sandwiched between two successively cast layers of plaster (3, 4) in a suitable mould, or alternatively, plaster containing randomly dispersed fibres is allowed to set in a mould. The cast panels may be L-shaped, Figs. 2, 3 (not shown). <IMAGE>

Description

SPECIFICATION Plaster cladding The present invention relates to plaster cladding suitable for walls or ceilings and to processes for manufacturing such cladding.

Traditionally, the finishing or skimming of a wall or ceiling with plaster (to a depth of about 2 mm) to provide a smooth and uniform surface suitable for painting or "wall papering", requires considerable skill, especially when large areas are involved, i.e. areas of more than about 1 sq.

metre. Thus, the amateur plasterer or DIY enthusiast, unless particularly skilful, or prepared to accept a poor finish, is invariably faced with the expense of professional help in order to achieve a satisfactory plaster finish.

The present invention seeks to overcome the above problem by providing the unskilled plasterer with a pre-finished plaster panel which when secured in position requires the minimum of skill to finish-off.

Panels according to the present invention are thereby a finished alternative to the traditional plaster board panel with its subsequently applied plaster finish (for example, as may be fitted to a timber frame work or studding). Panels made according to the invention may also be battened directly to walls or ceilings in place of a traditional rendering coat and plaster finish.

Accordingly, the present invention provides a pre-cast fibre reinforced plaster panel the exposed face of which is in a finished condition.

The "exposed face" of the panel is that side of the panel which, after the panel has been fitted in position, is on view and may be painted or otherwise covered.

The expression "finished condition" is used to describe a smooth uniform plaster finish equivalent in appearance and workmanship to that attainable by the most skilful of professional plasterers.

The present invention also provides a process for manufacturing a pre-cast fibre reinforced plaster panel as described above comprising the steps: (i) introducing a first quantity of fluid plaster into a mould for the panel having a smooth facing surface, (ii) placing a layer of fibrous material over at yeast a substantial part of the exposed surface of the plaster in the mould, (iii) introducing a second quantity of fluid plaster into the mould to cover the layer of fibrous material, and (iv) allowing the plaster to set and removing the cast panel from the mould.

As an alternative to the above process, steps (ii) and (iii) may be omitted and short discrete fibres randomly dispersed in the fluid plaster prior to introducing into the panel mould.

It is essential that the panels are pre-cast in a mould having a smooth, uniform and unblemished facing surface, and subject to these requirements a variety of mould facing materials may be employed.

Advantageously, the plaster panels are reinforced with a coherent fibrous mat comprising, for example, glass fibres, which is sandwiched between two layers of plaster.

Alternatively, short discrete glass fibres may be randomly dispersed throughout the plaster panel.

Other fibres that may be used, either in the form of a mat or loosely, include those derived from polyamides, polyesters or polyolefins.

Desirably, a fibrous mat with a relatively open structure is used to permit the easy penetration thereof by the fluid plaster during the casting process, resulting in a secure bond between the components of the panel.

In order to make an "invisible" joint between abutting plaster panels or between panels and other surfaces, the edges of the exposed face of each panel may be chamfered to provide, respectively, either a full "V" or substantially half a "V"-shaped channel when the panels are secured in position. The channel is then filled with a suitable filler material, such as a cove adhesive (for example, as sold under the trade mark GYPROC) and, if necessary, rubbed down to leave a continuous flat finished surface.

The present invention may be further illustrated, but not limited, by reference to the accompanying drawings in which: Figure 1 shows a portion of a pre-cast plaster panel which has been cut away in part to expose the fibrous layer, and Figures 2 and 3 show, respectively, portions of pre-cast plaster panels suitable for inner and outer reveals, likewise cut away in part to expose the fibrous layer.

Referring to the figures, each panel 1 comprises a fibrous mat 2, typically of glass fibre, interposed between two layers of plaster 3/4. The finished plaster layer 3 may be chamfered or splayed 5 at its edges so that the panel when abutting another similarly chamfered panel, forms a "V"-shaped channel which may be conveniently filled and, if necessary, rubbed down to give a smooth flat continuous surface finish. When abutting other surfaces, a substantially half "V"shaped channel may be formed which can also readily be filled and finished as described.

Indentations 6 may also be provided so that the heads of respective panel fixing nails can be concealed without damaging the surrounding plaster surface. Nails are driven into a panel until a small hole is left which is then filled and finished as described above.

Typically, a panel measuring approximately 2.4 m by 1.2 m or 1.8 m by 0.9 m in size would be cast to a final thickness of about 12.5 mm, and for panels of this size a fibrous mat weighing 1 50 gms to 550 gms per sq. metre, but preferably of the order of 280 gms per sq. metre, has been found to be satisfactory.

Example About 17 kilograms of fine casting plaster (powder), for example, as sold under the trade mark GYPROC, was mixed with approximately 6 litres of water and stirred to provide a consistent, viscous, but fluid plaster mass. The plaster was then poured into a moulding tray having a polished "plastic laminate" surface measuring roughly 1.8 m by 0.9 m (which had been precoated with a mould release agent, such as petroleum jelly) to a depth of just over 6 mm.

After a short delay to allow the plaster to partially set, a pre-cut open mesh glass fibre mat weighing 280 gms/sq.m. was laid over the plaster in the mould covering it totally. Further plaster was then added to the mould until the total thickness of the plaster/fibre glass laminate was about 1 2.5 mm.

The plaster was then allowed to set hard, which took about 20 minutes.

After setting and on removing from its moulding tray the reinforced plaster panel was found to have an exceptionally smooth facing surface, and due to the presence of the layer of glass fibre, to be stable, coherent and readily handleable.

To assist the making and finishing of a good joint between abutting panels or between panels and other surfaces, the edges of the exposed face of the panels were chamfered or splayed up to 3 mm., so that when, for example, two panels were abutted together they provided a "V"-shaped channel, which could be simply filled with a plaster filler or preferably a cove adhesive, (for example, as sold under the trade mark GYPROC), which after setting could be rubbed down in the usual way.

Since panels according to the present invention comprise only non-flammable materials, they possess good fire resistent properties.

Claims (Filed on 15/12/82).

1. A precast fibre reinforced plaster panel the exposed face of which is in a finished condition.

2. A panel according to Claim 1 in which the fibre reinforcement comprises a coherent fibrous mat.

3. A panel according to Claim 1 in which the fibre reinforcement comprises short discrete fibres randomly dispersed throughout the panel.

4. A panel according to Claim 2 or Claim 3 in which the glass fibres are used.

5. A paneL according to any one of Claims 1 to 4 in which the plaster is a fine casting plaster.

6. A panel according to any one of the preceding claims in which the edges of the exposed face are chamfered.

7. A process for manufacturing a precast fibre reinforced plaster panel the exposed face of which is in a finished condition comprising the steps:- i) introducing a first quantity of fluid plaster into a mould for the panel having a smooth facing surface, ii) placing a layer of fibrous material over at least a substantial part of the exposed surface of the plaster in the mould, iii) introducing a second quantity of fluid plaster into the mould to cover the layer of fibrous material, and iv) allowing the plaster to set and removing the cast panel from the mould.

8. A process for manufacturing a precast fibre reinforced plaster panel the exposed face of which is in a finished condition comprising the steps:- i) introducing a quantity of fluid plaster containing short discrete fibres randomly dispersed therein into a mould for the panel having a smooth facing surface, and ii) allowing the plaster to set and removing the cast panel from the mould.

9. A process according to Claim 7 in which the fibrous material comprises a coherent fibrous mat.

10. A process according to Claim 7 or Claim 8 in which glass fibres are used.

1 A process according to Claim 7 or Claim 8 in which the plaster is a fine casting plaster.

12. A precast fibre reinforced plaster panel substantially as hereinbefore described with reference to the Example.

1 3. A precast fibre reinforced plaster panel substantially as hereinbefore described with reference to the accompanying drawings.

14. A process for manufacturing a precast fibre reinforced plaster panel substantially as hereinbefore described with reference to the Example.

1 5. A wall or ceiling when fitted with precast fibre reinforced plaster panels according to any one of Claims 1 to 6 or 12 to 13.

1 6. A wall or ceiling when fitted with precast fibre reinforced plaster panels when made according to any one of the processes of Claims 7 toll or 14.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (14)

**WARNING** start of CLMS field may overlap end of DESC **. (powder), for example, as sold under the trade mark GYPROC, was mixed with approximately 6 litres of water and stirred to provide a consistent, viscous, but fluid plaster mass. The plaster was then poured into a moulding tray having a polished "plastic laminate" surface measuring roughly 1.8 m by 0.9 m (which had been precoated with a mould release agent, such as petroleum jelly) to a depth of just over 6 mm. After a short delay to allow the plaster to partially set, a pre-cut open mesh glass fibre mat weighing 280 gms/sq.m. was laid over the plaster in the mould covering it totally. Further plaster was then added to the mould until the total thickness of the plaster/fibre glass laminate was about 1 2.5 mm. The plaster was then allowed to set hard, which took about 20 minutes. After setting and on removing from its moulding tray the reinforced plaster panel was found to have an exceptionally smooth facing surface, and due to the presence of the layer of glass fibre, to be stable, coherent and readily handleable. To assist the making and finishing of a good joint between abutting panels or between panels and other surfaces, the edges of the exposed face of the panels were chamfered or splayed up to 3 mm., so that when, for example, two panels were abutted together they provided a "V"-shaped channel, which could be simply filled with a plaster filler or preferably a cove adhesive, (for example, as sold under the trade mark GYPROC), which after setting could be rubbed down in the usual way. Since panels according to the present invention comprise only non-flammable materials, they possess good fire resistent properties. Claims (Filed on 15/12/82).

1. A precast fibre reinforced plaster panel the exposed face of which is in a finished condition.

2. A panel according to Claim 1 in which the fibre reinforcement comprises a coherent fibrous mat.

3. A panel according to Claim 1 in which the fibre reinforcement comprises short discrete fibres randomly dispersed throughout the panel.

4. A panel according to Claim 2 or Claim 3 in which the glass fibres are used.

5. A paneL according to any one of Claims 1 to 4 in which the plaster is a fine casting plaster.

6. A panel according to any one of the preceding claims in which the edges of the exposed face are chamfered.

7. A process for manufacturing a precast fibre reinforced plaster panel the exposed face of which is in a finished condition comprising the steps:- i) introducing a first quantity of fluid plaster into a mould for the panel having a smooth facing surface, ii) placing a layer of fibrous material over at least a substantial part of the exposed surface of the plaster in the mould, iii) introducing a second quantity of fluid plaster into the mould to cover the layer of fibrous material, and iv) allowing the plaster to set and removing the cast panel from the mould.

8. A process for manufacturing a precast fibre reinforced plaster panel the exposed face of which is in a finished condition comprising the steps:- i) introducing a quantity of fluid plaster containing short discrete fibres randomly dispersed therein into a mould for the panel having a smooth facing surface, and ii) allowing the plaster to set and removing the cast panel from the mould.

9. A process according to Claim 7 in which the fibrous material comprises a coherent fibrous mat.

10. A process according to Claim 7 or Claim 8 in which glass fibres are used.

1 A process according to Claim 7 or Claim 8 in which the plaster is a fine casting plaster.

12. A precast fibre reinforced plaster panel substantially as hereinbefore described with reference to the Example.

1 3. A precast fibre reinforced plaster panel substantially as hereinbefore described with reference to the accompanying drawings.

14. A process for manufacturing a precast fibre reinforced plaster panel substantially as hereinbefore described with reference to the Example.

1 5. A wall or ceiling when fitted with precast fibre reinforced plaster panels according to any one of Claims 1 to 6 or 12 to 13.

1 6. A wall or ceiling when fitted with precast fibre reinforced plaster panels when made according to any one of the processes of Claims 7 toll or 14.