A range of smart shade devices come in trendy styles and vibrant colours and many offer reassuring claims of maximum ultraviolet radiation (UVR) protection. CHOICE has found, however, that the UVR rating of the shadecloth is only half the story.
The shadecloth industry is largely unregulated and serious knowledge gaps exist in the way these devices should be designed and installed. Ignorance of the level of shade coverage necessary, the wrong choice of materials, such as shade fabric with too low a UV protection level and where a shade structure should be orientated in relation to the sun may all contribute towards a structure that provides dangerously inadequate protection.
If the shadecloth is improperly stretched due to incorrect installation, this could alsohave a negative impact. “The UVR block is the single most important determinant of assessing the degree of protection against sunburn. But when a shadecloth is stretched due to improper installation, its UVR could be lowered,” says Christopher Nolan, managing director of Nolan Warehouses.
Please note: this information was current as of December 2008 but is still a useful guide to today's market.
Can you trust the industry?
With the exceptions of Queensland and Victoria, where installers must be backed with valid builder’s licences, anyone can set themselves up as a shade installer.
Even with a builder’s licence, there is no guarantee an installer will have any specific qualifications, experience or advanced knowledge of shade devices and their correct installation process. This means your installer can use a high-protection shadecloth, but he may install it in such a way that its stated UV protection is compromised.
“There is no formal education process of how to put up a shadecloth, so the only way is to go out there and do it,” says John Simmonds, director of Billabong Shades in Victoria. “The problem with this trial-and-error method is that sometimes the error is made and the customer has to pay for it.”
Stretching the truth
To our knowledge, no shadecloths have been tested for any change in UVR protection level resulting from being stretched when in use.
Currently they are tested for how much UVR the materials transmit, according to the requirements of Standards Australia and for tear and tensile strengths. There is no standard test method to test the change in UVR transmitted for material under stretched conditions
The School of Optometry and Vision Science at the University of NSW has performed tests on shadecloth to the Australian Standard. Professor Stephen Dain, director of its Optics and Radiometry Laboratory, says that how much a shadecloth stretches will vary with installation, which is a problem for devising a test method that includes a stretched state. “How much shadecloths stretch depends on how and where they are supported in the installation. So a shadecloth manufacturer should not be governed by what is out of their control,” says Dain. “Generally, knitted shadecloths do stretch and would transmit more UVR than unstretched." Woven shadecloths, he says, do not stretch much at all.
Classification of sun protection levels
The Australian Standard for sun-protective clothing includes a classification system that is similar to that used for sunscreen. Depending on how much UVR is blocked out by the cloth, the cloth may be described as offering ‘Good protection, ‘Very good protection’, or ‘Excellent protection’.
The Cancer Council of NSW believes there is a need for a similar system for the UVR protection of shadecloth. “An Australian Standard for shadecloth similar to the classification for sun-protective clothing will improve consumers’ ability to identify products with a low or high UVR protection level.”
A Standards Australia spokesperson explained that shadecloth differs from sun protective clothing in that factors such as the design and size of the shade structure, distance from the subjects, the level of reflected and diffused radiation, as well as the physical location of a person within the shade structure, can affect the level of protection provided. This is why the sun-protective levels of shadecloth, or a classification as such, is not included in the Australian Standard for shadecloth.
Standards Australia told CHOICE it has not received any proposals or requests to review the existing standard for shadecloth but welcomes anyone who wishes to do so (go to www.standards.org.au).
Given that the performance of a shadecloth depends on the way it is designed and installed, it is important to find a skilled and experienced designer and installer. See Council Cancer guidelines for things to look for.