Plastics

There are many grades of plastic produced and many are supplied self-finished and intended to be maintenance free (see BS 6150 : 2006 - Code of practice for painting of buildings - for further information).

ABS or Acrylonitrile-Butadiene-Styrene

This is the grade of plastic used for waste pipes and fittings. If painting is required, do not abrade with glass paper as this will degrade the plastic.

Expanded polystyrene

This is available as tiles or in sheet form. It has excellent insulation properties but is very fragile and so easily damaged by impact or abrasion, as well as being flammable. Expanded poystyrene is for interior use only and must not be painted with solvent based paints, as this will increase the fire hazard of this material and the solvents may even dissolve the polystyrene.

Fibreglass or GRP

This is a combination of fine fibres of melted glass which have been woven into matting and polyester resins (see BS 6150 : 2006 for further information). This mix of the glass fibre matting and the resin is built up in moulds to form the required shape. The finished item has a very hard glass like finish that is difficult to paint due to poor adhesion of surface coatings. Most fibreglass items are coloured during manufacture and are intended to be maintenance free. Garage doors are a common fibreglass item used in the building industry. If painting is necessary, thoroughly abrade the surface with wet or dry abrasive paper and white spirit, to provide a mechanical key. Rinse to remove residues.

Melamine

This is a plastic laminated on to a surface such as chipboard. Formica is a brand name associated with the Building Industry. It is a plastic laminate which is usually stuck down on site to work tops, etc. by carpenters. Melamine is often used for making furniture. Laminated plastic surfaces are not really suitable for painting due to poor adhesion of surface coatings.

Perspex

This is a brand name for methyl methacrylate. It is a transparent grade of plastic used for roof sheeting. It is available in either flat sheet or corrugated and can be used for safety purposes where glass would be dangerous. Perspex should not be painted due to poor adhesion of surface coatings.

Plastic Coated Metal, Plastisol or PVF2

This is manufactured for industrial use. Its main use is for cladding and 'finished' trim such as roller shutter doors, etc where a very tough durable mantenance free finish is required.

A specialist paint system is required as plastisol and organisol grades suffer from plasticiser migration unless sufficiently weathered (see BS 6150 : 2006 for further information).

UPVC or Unplasticised Polyvinyl Chloride (for Gutters, Downpipes, Rainwater Goods etc.)

This is the plastic most commonly found in the Building Industry and is generally in the form of plastic gutters and pipes (it can also be used for replacement doors and windows, see below). It is supplied self finished and is intended to be maintenance free. If painting is required, do not abrade with glass paper as this will degrade the plastic.

UPVC or Unplasticised Polyvinyl Chloride (for Replacement Doors and Windows etc.)

This is the grade of plastic commonly used for replacement doors and windows (it can also be used for plastic pipes and gutters, see above). Replacement windows and doors are intended to be maintenance free but are prone to discolouration after a period of up to ten years.

If painting is required, do not abrade with glass paper as this will degrade the plastic.