This client recently called this house at Runaway Bay. He asked us to come and sort out the subsidence behind the wall which was becoming increasingly of concern to him as it was near his pool.We pulled back the pavers and pebbles to find a void had indeed developed.
The first thing we needed to do was correct the cause of the subsidence. In this case the wall's weepholes were blocked and in some instances were allowing the material from behind the wall to flow out. Also the wall's construction joints were no longer sealed and a large crack had opened up in the footing of the wall. A team 'The Canal Wall Doctor'were called in to get the wall back into order. Canal Wall Doctor are a part of Gold Coast Barges. The team specifically target corrections to canal walls.You can find out about them here canalwalldoctor.com.au
Firstly the team installed filter and plugs and clearing and cleaning the weephole the allow the weephole to function as it was designed to do. The team attended to cleaning priming and sealing the Construction Joint with marine Sealants recommended by our engineer. The wall was high pressure cleaned and oysters were removed to 400 mm below the high tide mark and adjacent to weepholes and construction joints. A sealant was applied tot he wall to slow the deterioration of the surface of the wall.
The Footing had a crack which was opening up and was allowing material to come forward. Sand was pumped into the subsidence area and pebbles and pavers were reinstated.