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FREQUENTLY ASKED QUESTIONS:        STYRENE CORNICES

What are NMC cornices made from?  NMC Nomastyl range is made from high-density, extruded closed-cell polystyrene.  This dense foam is satin-smooth for a beautiful finish.  Closed-cell styrene differs from normal polystyrene in that it is not made of up little “snow-balls” compressed together.

What lengths do they come in?  NMC products come in 2m lengths for ease of handling, storage and installation by a single installer.

How are they joined?  Lengths of cornice are butt-joined on the installation surface with a narrow bed of adhesive which forms an important expansion joint

How are the joins treated?  Once the cornices have set, joins are lightly sanded and masked with glue.  Once painted, joins are easily hidden.

How does it stay in place while glue dries?  NMC Cornices are extremely light, and require no screws or nails to hold them in place.  In the event of slight misalignment due to an uneven surface, panel pins can be used to temporarily hold the cornice in place until adhesive is dry.

What are they stuck on with?  NMC provides a pre-mixed acrylic paste which acts as both an adhesive and a filler.  It dries to a smooth sandable finish but retains a degree of flexibility for movement.  NMC adhesive sticks to all building surfaces including wood, tiles, wall-paper, glass and paint. Standard cove bond works, but the NMC international warranty on adhesion is voided if other adhesives are used 

Must they be painted?  Yes, the finishing coat must be applied directly to the polystyrene.  NO UNDERCOATING is required. Any water or oil-based paint can be used, and adheres well to the cornice surface.  Any paint containing solvents (including aerosol paints and certain plaster-primers) must be avoided as they react with the polystyrene.

Will they crack?  NMC products are designed to flex with the building. In cases of excessive building movement, cornices may part or crack, but this usually follows other visible cracking such as drywall or plaster cracks. A flexible adhesive filler (acrylic filler) will correct this

How is is cut?  NMC polystyrene can be cut with any fine-toothed saw (including hacksaw), utility knife or other sharp blade.  Hotwire or power saws can be used.