Recommended installation detail for Aluminium Frangible Poles

Foundations should be excavated to the required depth maintaining a minimum diameter of 400mm. Remove all loose debris prior to pouring concrete.

When setting out and pouring concrete on multi pole sites the kerb side socket should always be installed first. The sleeve must be centralised in the hole and set on a concrete base ensuring the sleeve top is between 50 – 90mm above ground level. The sleeve must be placed with the locking bolts facing the oncoming traffic.

Using only wet concrete, carefully pour around the sleeve up to ground level. It is important to ensure that during the final pour the sleeve remains perpendicular by using a spirit level across the sleeve top with sleeve remaining in the centre of the foundation.

With the kerbside sleeve in place, and assuming the site is level, the process is repeated with the remaining sleeves, ensuring the top of each remaining sleeve is set level and perpendicular with the kerbside sleeve.

When the concrete is sufficiently hardened, generally 24 hours, the poles are placed in the sleeves and firmly secured using the security bolts and transition wear shoe provided. Assuming that all sleeves are correctly installed and the poles are the same length, the pole tops should be level and ready to install the sign.

For sloping sites, sleeves should be installed as above: 50 – 90mm above ground, the difference in the sleeve levels should be compensated for by calculating the pole lengths to ensure the pole tops are level.


For adequate foundation strength, it is recommended that concrete of not less than 28mpa is used.

To ensure that frangibility works within the requirements of NCHRP-350, all pole sizes 65mm NB and above must be installed using a matching sleeve, and all sleeves must be fully encased using wet premixed concrete.

Using the Signfix Wind Loading Charts, check the correct pole size and number of poles to be used for each installation. N.B software version is now available on request.

It is recommended that foundation details are obtained from a local Engineer prior to any installation.

To prevent difficulty in removing the security bolt from a damaged or bent pole, all sleeves must be sited with the locking device facing oncoming traffic.

The Stainless Steel Transition Shoe MUST be placed between the pole and locking bolts and tightened evenly between 10 & 12 Nm.

To prevent water ingress standard galvanised post caps or equivalent must be used.

Restraint devices are recommended to be fitted in high volume vehicle / pedestrian areas.

In sandy conditions it is recommended that a Silicon Bead is placed around the sleeve top to prevent the ingress of sand into the sleeve. It has been found that sand deposits between the pole and sleeve can wedge the pole and prevent removal.