SELECTING THE CORRECT ANCHOR FITTING

SELECTING THE CORRECT ANCHOR FITTING 

The right fitting is determined by the size of the structure, the loads imposed by the structure, distance between anchors,the strength of the anchor and the substrate to be fixed to.

The holding power of any anchor is directly related tho the diameter of the embedment hole so it is critical to ensure the hole diameter is correct. An inappropriate hole diameter from using an incorrect drill bit size may cause reduced loads or failure.

Safe Working Loads of Fitting/Anchor

The design load should not equal the pull out load of any anchor. Maximum pull out load is the load applied to destruction which is the point at which the anchor begins to fail. A safe working load of 3-4 times of the maximum stated value should be applied for safety. Consulting engineers may be used to calculate safety factors.

What fitting to use in DIY applications.

Larger fitting typically offer a higher safety work load than a smaller fitting in the same category. Consider using a slightly larger anchor if unsure of strength. 

When maximising the area under cover, connect the sail as closely as possible to the connection point. D shackles are a common option. Because there is little tolerance for manual tensioning the sail needs to be large enough to fit close to the connection point.

Turnbuckles which offer at least 100mm of threaded rod provide a large range for tensioning. The bigger the turnbuckle the more capacity there is available for tensioning but also bear in mind that turnbuckles will reduce the size of the shaded area as turnbuckles take up space. Bear this in mind when considering how much shade you need. Turnbuckles are useful if the sail is to be pulled down from time to time as tension can be loosened. 

Eye bolts and eye nuts are commonly fitted to a post as the initial fitting at the connection point. They are attractive and take up little space.