Residents of Mascot Towers have made an emotional plea to the government for help as they prepare to pay for urgent repair works next week. The repairs will cost the 130 owners between $5,000- $14,000 a month each for nine months. Banks have refused loans to the residents. Image: News Corp Australia

Sydney’s compromised Mascot Towers could face “structural failure” unless urgent repair works are completed, according to engineers who have discovered new cracks in the apartment block.

The 132-apartment tower was evacuated in mid-June after cracking was found in the primary support structure and facade masonry.

New advice from a structural engineer - sent to owners and residents on Tuesday - suggests the building’s existing cracks have widened.

Additionally, new cracking has developed in or around the northeast transfer beam of the building, and at all basement parking levels.

Increased cracking in the basement footing slab, which supports the towers, is also of “significant concern”, Tuesday’s update states.

“(We) have been advised that remediation of the bearing capacity of the soil underneath the slab is now required on an urgent basis so as to avoid a structural failure in the north eastern tower one corner,” the advice reads. Cracks currently range between 0.2 and 0.5 millimetres.

“It is our current view that once the cracking reaches 0.8mm the structure would be deemed unsafe,” the structural engineer warns.

The update - provided by law firm Mills Oakley - also says engineering consultants believe work at a neighbouring Aland development caused some of the problems plaguing Mascot Towers.

“The design and construction of the shoring system and waterproofing utilised in the excavation of the basement levels of the neighbouring Peak Towers development ... has likely caused the erosion of fine particles and the destabilisation of land supporting Mascot Towers,” the update states. Preliminary soil testing also indicates there’s been a “significant loss of soil bearing capacity” through the creation of voids or zones of very loose sand substrata compared to tests done before construction.

The Natural Resources Access Regulator indicated “de-watering” of the Peak Towers basement recently ceased, which coincided with a rise in groundwater levels near Mascot Towers, the update states.

Aland has previously told AAP it’s confident an independent investigation will confirm issues at Mascot Towers are unrelated to nearby construction. However, there could be some good news for Mascot Towers owners and residents as experts believe a “viable and permanent remediation solution” could be implemented once several matters are addressed.

These include the completion of effective waterproofing of the basement of Peak Towers, grout injection to stabilise the foundations at Mascot Towers, and providing a fail-safe for any beam failure through “propping”. AAP has contacted Aland for comment.