GB2306966A - Building materials and elements - Google Patents

Abstract

A material comprising sand and 1-6% by wt polybutadiene is used to render walls or to make building boards. Thermal insulation substances and fibres may be incorporated into the material. The board may have sheets eg of cardboard on its faces. Screws and nails can be fixed directly to the boards without the use of eg wall plugs.

Description

BUILDING PUBIS THIS INVENTION relates to building elements.

According to one aspect of this invention a building element comprises a mixture of dry sand and polybutadiene, with polybutadiene from 1 to 6% of the mixture by weight.

Preferably the polybutadiene is from 2 to 4% by weight of the mixture.

The element may be in the form of a board.

The mixture may comprise thermal insulating material.

The mixture may include material to increase flexibility e.g. natural or synthetic fibres.

One or both faces of the board may have cardboard or other protective sheet adhered thereto.

The mixture may be in the form of a surface rendering.

From another aspect the invention provides a board comprising a layer of material incorporating thermal insulation material.

The invention may be performed in various ways and one specific embodiment with possible modifications will now described by way of example with reference to the accompanying drawing which shows a board in section.

Generally a board 10 forms a wall boarding and partitioning board for use in the construction of for example houses, offices, shops, for the internal cladding of walls and ceilings or for forming a wall or partition.

The board 10 is made using kiln dried quartz sand and the addition of a liquid polybutadiene. The board 10 is constructed in a similar way to existing plaster board, i.e. an exterior layer of cardboard 11 on either side of the board. A bonding agent is applied during manufacture to ensure adhesion of the cardboard to the board 10.

The use of board 10 is particularly beneficial because screws, nails and other fixings can be directly fixed into the board 10 without additional fixings, e.g. wall plugs.

The board 10 is strong and also efficient with regard to fire resistant properties.

A suitable adhesive is used as bonding agent e.g. watersoluble adhesive.

The board 10 is formed by mixing kiln dried quartz sand and liquid polybutadiene, with the liquid polybutadiene forming between 1% and 6% by weight of the mixture preferably from 2 to 4% by weight. Below 1% some sand particles may lack some coating of polybutadiene, over 6% and the mixture may be difficult to set.

The mixture 12 is placed in a suitable mould and allowed to harden under the action of oxygen for example for 10 hours.

The sand will typically take up water from the atmosphere, typically up to 2% by weight moisture content, and this is understood in the term dry sand.

A suitable polybutadiene is sold under the name UNIVEST S by Huls Aktiengesellschaft of Marl, Germany.

In addition to a standard board 10 manufactured with dry quartz sand and polybutadiene, the addition of various thermal insulating products (e.g. polystyrene, polyurethane, vermiculite, expanded clay) can be incorporated into the board to significantly improve the thermal insulating properties. This is achieved by adding the particulate insulating product to the mix prior to hardening.

Materials for example natural or synthetic fibres can be added prior to hardening to improve the flexibility of the product.

Also in view of the significant strength of the board 10 compared with normal plaster board, it is possible to manufacture the product with a cardboard 11 casing only in one face, leaving the other showing the natural finish, thus significantly reducing the necessity of applying a full application of skimming plaster when the boards are fixed to internal walls of buildings.

The board can be used internally (indoors) and externally (out of doors).

In one example of the invention the mixture is used as an internal or external rendering before setting. The material sets after application as a render.

A mixture of kiln dried quartz sand and added polybutadiene ranging from 1 - 4% preferably 2-4% by weight of the mixture gives a material suitable for internal and external rendering of houses, offices or other surfaces. A suitable acrylic binder is applied to the surface to be rendered before application of the sand/polybutadiene mixture.

Claims (10)

1. A building element comprising a mixture of dry sand and polybutadiene, with polybutadiene from 1 to 6% by weight of the mixture.

2. A building element as claimed in Claim 1, in which the polybutadiene is from 2 to 4% by weight of the mixture.

3. An element as claimed in Claim 1 or Claim 2, comprising thermal insulation material.

4. An element as claimed in Claim 1 or Claim 2 or Claim 3, including material providing increased flexibility.

5. An element as claimed in any preceding claim, in the form of a board.

6. An element as claimed in Claim 5, in which one or both faces of the board has cardboard or a protective sheet adhered thereto.

7. An element as claimed in any of Claims 1 to 4, in the form of a surface rendering.

8. A wall having a rendering as claimed in Claim 7.

9. A building element substantially as hereinbefore described with reference to the accompanying drawing.

10. A board comprising a layer of material incorporating thermal insulating material.