Soft-roof Shade Structures

Materials selection

Cloth performance requirements to consider:

• blocks at least 80% of sunlight
• minimum 300 grams / sqm (GSM)
• Green or black coloured material
• 10 years age-life, and
• Higher quality and tighter weave fabrics will last longer.

Stressors to consider:

• exposure to sunlight
• dust
• accumulated debris
• water
• flexing, and
• failure or loosening connections. 

Design notes

• Cows resist being moved from bright areas to dark areas and prefer dappled shaded spaces so they tend to get used to a shade cloth structure more quickly than a solid roofed structure, provided the cloth is not billowing or flapping noisily.
• Shade cloth is also prone to bird, insect and rodent attack and areas not able to be hosed down or easily inspected for maintenance are particularly prone.

When installing footings, they should be:

• deep and concreted into the ground
• left to cure for 2 weeks before bearing any load
• free from collisions from animals and vehicles, and
• rigidly attached to a wide steel plate which is mounted on the foundation using bolted connections.

Design notes:

• Galvanised and threaded starter bars extending from the footing reinforcement are better for holding the plate than dynabolts.
• Apart from central supports these posts usually lean against the applied horizontal load to maintain the tension rather than being vertically upright. They need to be free standing in a farm situation. Guy cables must be avoided.
• If possible, position posts outside the animal traffic area so they are not in contact with manure and water or interfere with washing. If are located in the yard, place a raised concrete or PVC sleeve around the pipe to reduce corrosion potential.

Prevent cloth damage by:

• applying sufficient tension using flexible and adjustable connections to prevent tearing in the wind
• reinforcing cables and seams to distribute the point load at the stanchion to the fabric. This reduces the chance of rips and damage.

If shade cloth fastening is too loose:

• flapping causes excessive flexing and can generate noise during wind events which can disturb cows and irritate people.

If shade cloth fastening is too tight:

• a cable or cable connector could fail due to over-tensioning, i can cause instantaneous and catastrophic structural failure.

Shade cloth structures can become a hazard if damaged by storms. Blown cladding can provide serious injuries whilst broken cables and unsecured shade cloth can whip.

Height

A minimum height of 4.0 m is recommended.

If it's too low:

• cows might hesitate when entering the area
• it reduces effectiveness and installation of sprinklers and fans.

If it's too high:

• it limits the area of shaded footprint
• maintenance becomes difficult, especially if you're running machinery under the shade cloth, it can become damage from the exhaust.

The height of the structure, the angle of winter and summer sun and the required area of shaded footprint govern the orientation of the shade structure north-south or east-west.

If the structure is aligned east west the passage of the sun will generally ensure that the northern side of the structure is more exposed to sunlight than the southern.

If the paving is earthen and subject to animal traffic, drainage should be directed to formed drains.