Street: ST. GEORGES CRESCENT, DRUMMOYNE
Project: Bellmont Façade Engineering was engaged to undertake a preliminary visual inspection and report on the current condition of the floor slab after the recent removal of magnesite flooring at the above mentioned property.
Recommendation: Based on our preliminary visual assessment, we advise that the magnesite affected concrete was identified in several locations and excessive within two locations including the living room, kitchen, dining areas and bedroom.
It is our recommendation that the further exposure of several sections within the floor slab shall be conducted revealing the condition of reinforcement placed within the bottom layer of the concrete slab, this is due to severe corrosion of the existing top reinforcement within those allocated sections.
It will be also necessary that the other spalled concrete sections identified are also exposed to allow for structural assessment – destructive investigation to uncover the underlying reinforcing steel so that its condition can be assessed.
Item A: Magnesite Repairs including & floor levelling
Item B: Balcony Waterproofing Membrane, Tiling & New Doors
Item C: Balcony Cavity Flashing
Status: Currently in pricing stage of project. Expected to start early this year.
Street: EUROBIN AVENUE, MANLY
Project: Bellmont Façade Engineering were engaged by Strata Real Estate Services to assess the condition of the balcony slabs of 3 levels of residential units. Based on our inspection, it is our opinion that the cause of the separation between the masonry balustrades at the ends of the balconies and the building is due to excessive deflection and rotation of the cantilevering concrete slab balcony. The rotation is more pronounced due to the cracking in the slab.
Additionally the cracking within the slab indicates a localised rotation that has contributed to the separation. This cracking provides a water ingress point to access the steel reinforcement in the slab. The top reinforcement is the critical strength reinforcement for cantilevering slabs and the condition of the reinforcement needs to be verified, however the cracking evident is an obvious precursor to reinforcement corrosion.
The movement of the metal balustrade indicates a loss of connection strength of the middle post. It is our opinion that the metal balustrade requires being replaced due to non-compliant strength and also height.
Recommendation: Replace brick balustrades with lighter aluminium balustrades to significantly reduce the loading on the concrete slab.
Status: WORK IN PROGRESS. The front of the building’s three balconies have been complete. Left to do are the three balconies to the rear of the building.
Street: ASHBURNER STREET, MANLY
Bellmont Façade Engineering was engaged by Strata Choice to undertake a visual inspection of the internal cracking occurring within a unit on Ashburner Street, Manly. This inspection was undertaken on Wednesday 21st November 2018.
It was concluded that the internal cracking was likely caused by the weight of bricks that hold down what are called tie down supports. Such supports secure the roof and provide resistance against wind uplift. In this unit, strong multi-directional winds caused movement of the tie down supports which ultimately caused the horizontal cracking within brickwork.
Alternatively, the cracking could’ve also been a result of the corrosion of steel elements, a.k.a. ‘rust jacking’, where the displacement of building elements occurs due to the expansion of steel.
Subsequent to our inspection we would broadly recommend the following:
- Inspection of the remaining upper level units of the complex to ascertain whether similar cracking is visible on the interior rendered & exterior brick walls (where access is provided).
- Creation of a series of investigation holes in the walls (from inside the occupancy) to facilitate use of a bore scope camera to view the condition of brick ties and tie down plates or straps used and assess the level of deterioration.
The scope of works referred to within this technical specification is applicable to the façade of the building, the rooftop and internal works and includes:
Item A: Rooftop Repairs
Item B: Embedded Steel Fixing Removals
Item C: Steel support Beam Replacement
Item D: Steel Pillar Treatment
In solving these suspected issues Bellmont delivered the installation of new gutter brackets along the perimeter of the rooftop, removal of corroded pre-existing mild steel fixings, installation of new sheeting and flashings for skylight including complete weatherproofing, installed new sheeting accommodating existing vents and complete weatherproofing, as well as treatment of the steel pillars.
Recently, BellMont was employed to undertake an inspection of this property by the strata committee in charge of it. During our diagnostic investigations, we discovered that there was a large amount of concrete in the structure that was unsuitable and in need of remediation.
As you can see below, the defects were quite extensive and required some consideration on how to best approach the task at hand. It was decided that the most effective method to repair the damage before it worsened and caused any catastrophic failures, was to use hand applied repair methods.
This approach involves:
Below are some pictures of this process.
Often these defects are a safety concern and will only worsen over time. So if you're concerned about your concrete, don't hesitate to contact us and start the process now.