Materials

What shading material is best?

Common shading materials are:

• solid corrugated steel roofing or timber shingles
• PVC membrane
• shade fabric - sails or pavilions
• transparent roofing - polycarbonate or laminated glass
• trees or vines.

In selection consider the following factors:

UV barrier

Generally ultraviolet radiation (UVR) protection is directly related to the open area of the fabric or trellis.

• Ensure that sunshade fabric has a UV rating >94%.
• Pergolas and trellis are not effective unless covered with vines or fabric in the summer months.
• Ensure clear roofing material is polycarbonate with a guaranteed UVR rating. Some cheap PVC's do not provide good UVR barrier and deteriorate rapidly.

Warm shade

Due to sea breezes, NZ climate is temperate. Recent research of the Paraparaumu climate found that 69% of the time when UV protection is required the air temperature alone was too cool for comfort. People would desire to be in sun. The easiest way to provide UV protection and warmth is to use a transparent material. Polycarbonate and laminated glass provide over 99% UV protection but transmit the warmth of the sun. In coastal NZ, sea breezes are generally available for cooling.

Multi-purpose

The use of an impervious shading material creates a dry outside space in rainy weather. In areas with high rainfall, such a space can be very useful as a play-space and for exercise classes.

Cost

Shade fabric structures tend to be less costly, but this needs to be weighed against the amenity value of using a translucent shading material to create a warmer and drier facility. To prolong the life of the material, sunshade fabric should be removed over winter when not required.