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Stopping Inner West house movement and saving a gum tree
Our Brief
For over a decade, the owner of this Georgian style home in Sydney’s Newtown had repeatedly repaired his home’s wall cracks. Cracks would appear, get repaired at great cost, only to reappear again later.
Fed up with spending so much money, the owner sought out a permanent solution and contacted us.
Upon arrival, we observed countless attempts had been made to repair the cracked walls. These failed repairs had resulted in layers of patching and plaster tapes pushing out from the structure.
This made it obvious that consistent, active house movement was the cause of the recurring cracks. But the reason for movement wasn’t so obvious.
Our Challenge
During our inspection, we used a variety of visual factors and surveying techniques to determine the house had been built on reactive clay soil. Periods of heavy rain would cause the ground to shift, causing house movement.
What was unusual was that the house was lifting AND sinking, simultaneously. During downpours, the house’s internal structure, sides and rear elevation would lift. But the front of the house would sink.
We determined this intense tug-of-war scenario between the front and rear of the house was the cause of the recurring wall cracks. But we still didn’t know why the front was sinking until we took a closer look at the enormous gum tree in the front garden.
We found the tree’s monstrous roots sucking up water from the reactive clay under the front of the house. During downpours, the rear of the house would lift as reactive clay absorbed water and expanded. But the front would subside as the tree took a large drink!
Our Solution
A multitude of repair methods were employed to fix all the house’s problems, both at a foundational level and above the ground.
We began with the most pressing issue — the subsidence at the front of the house caused by the gum tree. To stop further sinking, we injected our proprietary geopolymer resin solution, GeoPoly™, into the reactive clay under the front of the house. This underpinned and lifted the front of the house and also solidified the ground, negating the need to remove the tree.
To allow for natural house movement without wall cracks recurring, we strategically installed control joints around the house. To further strengthen the walls, we also installed our very own HelicalBars™.
Finally, to give the walls a smooth, beautiful finish we applied our very own FlexiCoat™ system and a fresh lick of paint.
The Outcome
Over a decade, wall cracks had returned again and again because the underlying faults of the house had never been repaired by previous contractors. Repeatedly patching and painting the house had been a waste of money.
Buildfix was able to restore the structural integrity of this beautiful Newtown house within days. With our help the owner didn’t need to call upon multiple companies and spend more money to make repairs. And going into the future, our work and expertise has saved the owner tens of thousands of dollars.
Having underpinned the front of the house, it no longer sinks. And the strategic installation of our HelicalBars™ and control joints have entirely stopped the wall cracks from returning.
We even managed to save the gum tree from being removed!
