With the interior now restored, the next stage is to reinstate the exterior to its original condition
One of the most significant and striking features of the buildings facade is the aluminum grille. Along with the stone work, it is an essential part of the buildings modernist appearance. If the grille was to fail and have to be removed, the cost of replacing it would be prohibitive and the building facade would loose its defining feature.
Unfortunately, it has had no maintenance for almost 60 years. Being aluminum, it has survived well but the grille was fabricated in two sections. They were joined from the back with flat steel bars. This has resulted in Galvanic corrosion. It occurs where there is both metallic contact and an electrolytic bridge between different metals. The least noble metal in the combination becomes the anode and corrodes. The most noble of the metals becomes the cathode and is protected against corrosion. In most combinations with other metals, aluminum is the least noble metal. Thus, aluminum presents a greater risk of galvanic corrosion than most other structural materials. In addition to this, the steel bars are rusted through in some sections.
The result is that the grille now slumps in the center on the horizontal plane and also bows back into the building on the vertical plane. It is likely that the aluminum behind the steel will be badly corroded.
To correct this we intend to:
- Remove the existing steel flat bars.
- Assess if any repair needs to be made to the aluminum grille.
- Jack up the horizontal slump with wedges and timber supports.
- Clean the back of the section.
- Attach a new 3000mm length of mill finished (not annodised or powder-coated) aluminum angle, 6mm thick x 40mm x 40mm. This will have superior strength and brace the section of grille over a longer section. This will be attached with aluminum rivets. This bracing technique will result in only one material / metal type and stop the Galvanic corrosion.
- The new bracing will be slightly visible from the street but should not detract from the appearance of the grille.
- This process will then be repeated on each of the 12 horizontal sections of the grille.
- The bolts anchoring the grille to the masonry will also be inspected but they appear to be in good condition.
- Once reinforced, the grille will be cleaned and re-polished restoring it original, modern gleam.
Cracked exterior slab
Behind the grille there is a narrow ledge that allows for window and grille cleaning and maintenance. The ledge, which is exposed to exterior elements, has a crack in the center. When purchasing the building, the building report found that this has no structural impact on the building but it does leak through to the ground floor porch below resulting in the paint blistering.
The proposed solution is to apply multiple coats of Ardex WPM 310 waterproof membrane. This will not be seen from the street or the interior of the building.
Prep & painting
The exterior of the timber windows and surrounding walls need stripping back to the original substrate, undercoating and painting. The windows are in good condition but are now at a critical state of disrepair as the bare timber is exposed and needs protection.
The entire first floor needs painting. The colour is Dulux Redwood, which is an exact match of the original exterior colour. The exterior framing of the windows is to be painted black which is also the original colour. Black and white window framing was a decor concept used throughout the building and is striking.
Fascia boards and flashings
As seen in the original photo of the ES&A Bank, the fascia boards created a crisp white band which capped the building. It is assumed that there was water penetration issues with this design.
We can see in the photo taken in 1971 that the fascia boards now have standard roof flashing which comes over the fascia. While this would greatly improve the impermeability of the roof, it has detracted from the architects original concept. The appearance is makeshift.
The solution proposed is to remove these flashings and replace with a custom pressed flashing. This would cover the roof edges and be siliconed off to prevent wind blown moisture penetration. It would also cover the entire fascia board. The material will be white Colourbond steel. This would greatly improve the fascia band and restore the original finish of the upper level of the building.
Flag pole reinstatement
A new aluminum flag pole to match the original is to be purchased and installed.
The current window awnings were not original as seen in the image opposite. They would have been installed later as the hot western sun became an issue. The awnings have reached the end of their life as they are coming apart and rattle in the wind. In addition to this, the awning over the back door did not allow for the security grill to open so had to be removed. The back office has not had an awning and in just one year the paint work has cracked with the hot summer sun. The protection they provide is essential.
It is proposed to replace the current awnings with slat awnings. This style of awnings were very popular and on trend with modernest houses. The example shown is from Rose Seidler House -1950. They are to be made from 100mm x 25mm aluminum rectangular section. They are riveted together on a supporting triangular aluminum bracket. The awnings are seen from the street.
New sky sign on the roof
The sky sign really adds to they dynamic asymmetrical appearance of the facade. We indend to add a new sign on the roof of spun and routed aluminium.