The property at 12 Eastern Avenue North Bondi is founded on shallow footings on sand. During renovation works the owner noted that the footing on the North-Eastern corner of the property had settled causing superficial cracking to the brickwork. Geotechnical investigation identified that the sand beneath the footing was soft. Access to the rear of the property was limited to a narrow pathway with a number of steps.

GFWAust carried out permeation grouting with stable ultrafine grout to provide underpinning of the footing. The ultrafine grout was mixed with a microsilica slurry to provide stability to the grout, and a superplasticiser to assist with dispersion of the grout in the sand.

The owner then required to excavate basement space beneath his house which meant undermining load bearing walls. GFWAust carried out additional permeation grouting to underpin the founding walls and allow excavation to proceed.