The final act is the re-waterproofing of the 35 storey apartment blocks roof. An aged and deteriorated bituminous membrane was removed to be replaced with the Sika Floor N – Elastic polyurethane membrane system. The system was to be applied to an exacting specification produced by Majcon which required detailed preparation of the roof slab by diamond grinding to remove residues of the old bituminous membrane and to open up the pore structure to receive the Sikafloor 160 – 2 part epoxy resin primer. Three coats of the Sika Floor N elastic membrane were then applied after suitable recoating and curing times. Technical reps from Sika Construction Chemicals regularly attended site to inspect the work in progress and to advise on tricky detailing issues and interfaces with roof plant areas and equipment.

The complete roof area, is now in the process of being paved with a porcelain paver from the Urban Surface collection supplied by Amber Stanmore. The 600×400 pavers are being mounted on paver pads supplied by Elmich.

At completion the whole roof area will have a smart new look and further works are planned into the future to enable the occupiers of this major high rise building to enjoy the amenity the roof area provides, an outstanding view point to enjoy those special views of Sydney Harbour.

The post Rooftop remedial waterproofing appeared first on Structial Building Pty Ltd.

In Sydney, Sydney Sandstone in most cases, provides a good stable material on which to found a building. If the rock layer is found at shallow to moderate depths then raft slabs, piers or piles can be utilised to provide effective footings. Smaller buildings, or buildings where the rock depth is excessive often resort to footing designs in the soil layers. Performance of footings in soil layers can vary depending on the applied loading, drainage and other environmental factors.

Inner Sydney is blessed with sandstone relatively close to the surface, or, there exists a relatively shallow sandy clay over that sandstone. As we move westwards deeper clay layers are found which often give rise to expansive clay conditions whereby clay layers shrink or swell depending on moisture content. Historically Sydney summers have provided good rainfall resulting in little difference in the moisture content of clay layers during summer or winter but of late more frequent drought conditions have caused a resurgence in damage to buildings due to the effects of expansive clays as the seasonal moisture differentials increase.

As a remedial building company and foundation repair experts we see foundation failure resulting from a variety of causes including inadequate initial understanding of the ground conditions leading to inadequate design. The old adage that ‘a site investigation is paid for whether it occurs or not’ often rings true as rectification costs mount.

Other causes of foundation failure include, inadequate control of ground water or changed ground water conditions. It is largely true that if you can control the water on site then the site is under control. Flooding, gradual seepage or installation of close by deep basements re-routing groundwater flow paths as an example, can all have damaging effects on footings.

Whilst there are many causes of footing failures in buildings, in all cases, there is a need to properly understand, design and construct remedial works to ensure effective repairs are undertaken. This requires the services of structural engineers to design the works and contractors to undertake the works. Both parties must be experienced and  skilled in works of this type to make the problems just go away…

Contact Structial today!

The post Best Methods for Foundation Repairs appeared first on Structial Building Pty Ltd.

So, what is it? Concrete cancer or concrete spalling, as it is also known, is generally caused by the corrosion of the reinforcing steel embedded within reinforced concrete building elements. As the steel corrodes, due to the presence of chloride salts or other contaminants, it expands causing the concrete surrounding it to crack and eventually spall off.  Whilst initially a minor problem, in time, if left unchecked, widespread spalling can lead to a loss of structural integrity and in severe cases structural failure. Spalling concrete becoming detached from buildings and structures can also poses a serious threat to the safety of the general public and property in and around them. Usually concrete cancer is attributable to the ingress of chloride salts from, marine environments or industrial processes, or carbonation due to prolonged exposure to carbon monoxide from vehicular traffic or other sources. Factors that can hasten the onset of concrete cancer include poor waterproofing, aggressive environments, poorly placed or finished concrete easing the path of contaminants through the concrete cover layer to the reinforcing steel, and poor design of the concrete structure.

Now that we know what concrete cancer is and the damage it can cause, let’s understand how to diagnose and do concrete cancer repair! A few tell-tale signs of concrete cancer will be cracking or crumbling concrete, rust stains, roof and internal wall leaks or bubbling concrete render. If you notice these, make sure you contact a professional (such as a structural engineer or remedial builder) to properly diagnose and correct the problem.

Minor instances of concrete spalling are generally addressed via patch repair procedures where concrete is repaired by breaking out the concrete at the repair site using jackhammers to expose the corroding reinforcing steel and them ‘chasing’ that corrosion until good, un-corroded steel is found. The corroded steel is then either cleaned or replaced and new steel is installed as per engineering requirements. Primer is then applied to steel and concrete surfaces and concrete repair mortar is then applied to reinstate the repair area to the original profile. Larger and more serious instances of spalling may necessitate more ‘heavy duty’ methods of removal, preparation and reinstatement. For example the use of hydro demolition techniques using water delivered at around 20,000PSI is  a highly effective method removing large areas of spalled concrete in an economical fashion. In such cases repair products are often spray applied using either wet or dry sprayed repair products or in larger flat areas repair products may be poured into prepared formwork. In all cases the repair of spalling concrete is a job for specialist consultants and contractors.

ACRA, the Australian Concrete Repair Association, is a good source of information and expertise on concrete cancer repair and other problems and its membership is vetted for quality and competence in the field. Structial Building are a member of ACRA and are happy to assist if you are concerned about spalling in your building or structure. https://acrassoc.com.au/

The post Is Concrete Cancer repairable? appeared first on Structial Building Pty Ltd.

ACRA aims to provide a forum that exchanges discussion of views in the concrete repair and remedial building industry in order to advance technologies and practices in remedial and associated industries. 

We look forward to joining the Association’s members who are at the forefront of concrete repair and remedial technology across Australia and New Zealand.

The post Proud member of ACRA appeared first on Structial Building Pty Ltd.

The existing sliding doors on this project in Cronulla, were inadequate to withstand the wind and water conditions they were exposed to.

Structial in cooperation with the Façade Engineer are replacing the sliding door and window assemblies on the eastern elevation, facing the beach, and making good all internal finishes. The new sliding doors and windows, supplied by G James Glass & Aluminium are all rated and tested to combat the elements and protect the residents.

With building defects becoming a major issue for the community, choosing the right builder for the job has never been more critical. Contact us to make Structial your remedial building partner.

The post Sliding Doors in Cronulla appeared first on Structial Building Pty Ltd.

A building’s façade is more than just an element that defines its external appearance; it also fulfils functions associated with weatherproofing, light transmittance, acoustics performance and energy efficiency.

Check out our Build Australia magazine editorial here.

The post Build Magazine October 2019 – Façades appeared first on Structial Building Pty Ltd.