Skin cancer can be dramatically reduced by effective preventive measures. One measure is to minimize sun exposure by staying in the shade during the hours of 10:00 a.m. - 4:00 p.m. This can be achieved by developing areas of outdoor shade, in turn reducing exposure to solar radiation.

There are several methods of shade design to consider, each with its own merits. Evaluate all methods and choose the option that works best for your situation. Assess each situation individually, taking into account the position, the design and the surrounding environment to ensure that optimal shade is provided.

Sun Protection Factor (SPF)
SPF is how much longer the skin covered by sunscreen takes to burn as compared to unprotected skin - the higher the factor, the better.

Ultraviolet Protection Factor (UPF)
The protective ability of a shade structure is measured by its UPF. The UPF of a shaded environment is similar to that of the SPF of sunscreen - the higher the factor, the better. The UPF is a scale that rates the protection provided by cloth materials. A material's UPF rating is based on the percentage of UV radiation transmitted through the material.

The following table is useful when selecting shade cloth. Aim for shade cloth that absorbs at least 93% of UV radiation, which is the minimum shade acceptable for protecting children.

	UPF Rating		% UV Radiation Absorbed		Protection Category
	15		93.3%		Good
	20		95.0%		Good
	30		96.7%		Very Good
	40		97.5%		Excellent
	50		98.0%		Excellent

(Source: ARPANSA 2003)

• Maximum protection from UV light all year
• Suitable side protection to reduce scattered UV radiation (UVR)
• Positioned with respect to outdoor activities

Good planning ensures effective shade. Whatever the scale of the project, planning should include:

• Understanding sun and shade
• Identifying where and when shade is needed
• Understanding your shade options
• Considering built vs. natural shade

Consider the following as high priority shade areas:

• Where outside activities occur during the hours of 10:00 a.m. - 4:00 p.m. (i.e., spectator seating, dining, break areas)
• Where the participants are children - (i.e., sports fields, playgrounds, theme parks, water parks)
• Where outdoor activities occur with minimal clothing - (i.e., pools, beaches)
• Where outdoor workers are exposed to UV rays and heat

Shade methods include the use of trees, man-made structures or a combination of trees and man-made structures.

Natural Shade - Trees
Keep in mind adequate shade is usually only achieved when a plant reaches its maturity - which may take up to 10 years! Careful planning at the planting stage is required especially with respect to species and location.

• The most effective trees have broad canopies, dense foliage and sufficient clearance beneath the canopy to allow access. Remember, the taller the tree, the less the shade.
• Select carefully to ensure the trees are appropriate for the soil type and climate in your area.
• Choose trees that are less likely to shed branches.
• Choose deciduous trees where you want winter sun.
• For the most effective shade, plant trees in groups.

Fabricated, Man-Made Shade

Combining Trees with Man-Made Shade
By using a combination of trees with man-made shade structures you achieve the ultimate shade:

• Quick shade
• Low-angle shade
• Aesthetically pleasing
• Control the amount of sun exposure - less in the summer, more in the winter

Best Fit

Strive for ultimate shade coverage. When choosing a shade structure, it is important to remember the size of the area you wish to cover, and the position of a person or the equipment in relation to the edge of the shade structure. This will impact the amount of UVR received. Although it is not always possible to achieve optimal shade, try to vision the ultimate and try to meet all your needs.

Consider the use of the shade area. This could include passive play, spectators or active sports, equipment coverage - all of which have different needs.

Consider the existing landscape. Well-planned shade will utilize existing features and acknowledge any potential problems such as highly reflective surfaces.

Know your site limitations. Consider potential problems including playground equipment interference, vandalism, visibility issues, and exposure to strong winds. These will impact maintenance costs. Appropriate design will eliminate or minimize potential problems if identified during the design phase.

Finally, always take into account building codes.

Best Value

Water Resistant vs. Waterproof
Waterproof covers are more costly than breathable fabric covers. Consider the application. Is waterproof truly required? While not waterproof, breathable fabric covers provide up to 80% water resistance and complete hail protection, and remember, they are much cooler.

Solid Roof vs. Fabric Roof

Solid roofs typically cost 50-60% more than fabric roofs. Fabric roofs are much easier to maintain. The breathable fabric prevents mold, mildew or termites. In addition, fabric roofs are far less costly to replace than solid roofs.

Form & Function: my new shade structure is beautiful but where is the shade!

Keep in mind that the protective function of the shade structure is more important than the aesthetic appeal. Although with proper design elements, both can be achieved.

• Continuous shade - Design with continuous shade in mind. By using structures that offer continuous shade and proper placement of multiple structures, the designer can avoid the less desirable "daisy effect" (this occurs when there are areas of sun coming through gaps or breaks in the fabric). The "daisy effect", though aesthetically pleasing, does not provide effective shade.
• Sails - Shade sails are large fabric canopies supported by columns or buildings without upper roof members. This is an extremely dramatic design. It is critically important that the sail is used in proper applications and positioned perfect for correct shade coverage. Very often this is not the case, resulting in very little shade.
• One super structure vs. multiple manageable structures - Multiple shade structures are usually the better solution, though there are projects that require a super structure. A super structure is one structure, one roof line encompassing an area greater than 40' x 50'. Through experience we have learned that this size structure is better suited for a solid roof, not a breathable fabric shade structure. Coverage can be achieved with fabric structures by interconnecting multiple structures (sharing columns, separate roof lines). Smaller structures are more manageable in terms of installation, maintenance and repair costs, and more pleasing in the landscape.

Positioning

The amount of protection offered by a shade structure varies with the angle of the sun. The shade casts may not always be directly beneath the shade structure. At certain times of the day, the shade may be outside the structure, providing negligible UV protection. The design of shade structures must maximize the shade cast for a changing solar angle.

A well-designed and correctly-positioned shade structure cast shade where and when it is most needed - at the right time of day and at the right time of year. Incorrect positioning of shade structures and trees can result in unexpected shadows that provide little shelter from the sun.

Use the following links to determine sun declination for your project:

• www.webshade.com.au

When designing and constructing a shade structure, the entire shade environment needs to be carefully considered. If you would like further information or assistance with your project, please contact us at info@apollosunguard.com.