Last week, we talked about the importance of protecting oneself from Ultraviolet (UV) exposure and how applying sunscreen and wearing protective clothing are beneficial to reducing UV exposure; shade is an extremely useful source in UV radiation (UVR) protection. Shade is another way a person can reduce exposure to UVR. 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 protection. 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.
Amounts of UV Radiation Absorbed and Level of Protection
% UV Radiation Blocked
|15, 20||93.3 -95.9||Good|
|25, 30, 35||96.0 – 97.4||Very Good|
|40, 45, 50, 50+||97.5 or more||Excellent|
There are several methods of shade design to consider, each with its own merits. With our blog series on Sun Safety, we will evaluate all methods and choose the option that works best for your situation. Let’s explore.
Requirements for Effective Shade
- Maximum protection from UV light all year
- Suitable side protection to reduce scattered UV radiation (UVR)
- Positioned with respect to outdoor activities
Planning Effective Shade
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
Critical Shade Areas
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
Types of Shade
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.
Things to keep in mind:
- 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.
- Ensure the selected 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
There are several different types of man-made shade; Portable & Permanent Shade Structures.
Portable Shade Structures
A shade structure is considered portable if it can be easily transported, erected and taken down, and used in different locations. Shade umbrellas are examples of portable shade. These items are very useful when you might not otherwise have access to shade. (i.e., when boating or at the beach).
Permanent Shade Structures
Permanent shade structures can stand alone or be built on existing buildings or structures. The advantages are:
- The shade cast is more predictable
- Immediate shade results
- Some types can be erected quickly
- Weather protection
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.
Next week we will dive into the different types of shade structures and the benefits of Apollo Sunguard’s shade structures.