Building Cladding Case study
This case study aims to highlight the specific needs of common but difficult modern cladding materials in respect to preforming building washes and ongoing preventive maintenance.
Materials discussed: Alcoubond, Powder coated aluminum and Hardy board type fibrous panels.
The apartments that make use of these materials were constructed in the 2000’s and belong to a group of many residential high rise complexes that are very similar in design, cladding materials used and also colors.
These buildings had at that time incorporated newer types of cladding materials and also new uses of existing materials, this also means that the building washing industry needed and needs to become more aware of the unique requirements of these materials when it comes cleaning them while preforming building washes.
This is mainly due to the cladding in question being easily damaged and not offering any result if washed incorrectly.
As well as Zenith property maintenances extensive knowledge and experience, Zenith has been in close contact with the manufactures and constructors of the buildings and materials that are in question and have discussed the correct procedure and techniques to use when preforming a building washes and maintaining buildings that make use of their cladding products.
Hardy board fibrous panels
The hardy board type fibrous panels have been mounted using screws set into collars, these panels are negatively recessed ie: the panels are fixed to a joining and sealing/ joining strip behind the panels themselves adding to a strong paneled effect on a larger scale.
These panels are quite resistant to degradation caused by the weather because most have been sealed quite well, however due to the textured nature of the boards themselves they can hold quite a lot of grime and dust within the profile of this texture, this is because there is more surface area for dirt and grime to cling to.
Making this problem worse is the fact that most of these boards have been coated with a matt or satin finish to accentuate the paneled or padded effect.
This use of matt finish is really bad for this application due to the reason above and also because of the fine texture being very easily marked by any sort of contact. Once marked because; the texture offers more surface area and is also quite porous it holds on to any soil really well and cannot be removed by any sort of building washing technique no matter how much time and effort is put in.
Also we have notice sub-par painting work done on these panels mainly the lack of undercoating, due to the nature of this fibrous panel and its white color you can clearly see the difference in tone between panels that have been under coated and the ones which have not been.
It is sadly a common sight when washing buildings that many commercial painting contractors have cut corners, skipped parts and do not show proper technical knowledge when applying coatings, although in this case the architect in charge most probably specified the coating sheen levels while still in the design phase.
This being said most of the panels problems (which are not serious at all) can be solved by adding a high sheen coating next time their repainted, this will make the panel less porous and thus offer less surface area to the environment which would aid with lessening the time frame needed between building washes .
Alucobond panels are a cladding material consisting of a core made out of polyethylene laminated with aluminum and coated by a pvdf (vinyl type) exterior layer.
Alucobond is a relatively new material and has proven to be wildly popular in many applications and still is today in public and private buildings all over the world, it gives the effect that any shape that is cladded with it is solid steel or depending on color, one large piece.
This gives freedom when designing buildings to make them look more like shapes or (if you like that sort of thing) works of art.
Alcuobond panels have proven to be quite resistant to degradation and staining when left for long periods of time without a building wash in normal conditions.
We have found that panels that are exposed to high levels of road dust and carbon build up loose their surface finish and become very matt and textured in appearance. This is due to the degradation of the outer coating as the road dust that sits upon its surface moves with the environmental conditions (wind and rain)and the dusts physical weight causing abrasion the surface over time like sand blasting does steel.
The panels are very resistant to seepage or cracking type damage because they have excellent sealing properties and good uv protection.
However the silicone seals between each panel are prone to break down via exposure to uvs and become brittle and lose their seal.
Also if the seal has too much of a recess between each panel it can cause water and dirt to sit in the ledge and over time cause run marks on each panel.
Many chemicals react adversely with the coating on alcuobond panels and this causes chemical burns on the panels, the most common cause of chemical burns on buildings in Auckland are by application of an unsuitable cleaning detergent by service providers.
Generally the main cause of damage to these panels over time is caused by abrasion due to the fact that they are very soft and can be scratched easily.
Environmental abrasion caused over time by particles in the air is due to the proximity of a road carbon or salt from the sea.
Many ill-informed service providers have also scratched theses panels by using incorrect brushes that are too stiff, these cause permanent brush and swirl marks.
A remedy this damage is not found by polishing the panel, due to the soft nature of the coating polishing only makes the damage worse.
The manufactures of alucobond recommend that panels be washed every six months to maintain shine and condition, they also recommend only one type of chemical detergent be used in the cleaning process to maintain their product warranty’s.
The panels themselves are quite weak and in most cases will buckle and dent if walked upon or asked to hold up against any pressure.
Zenith property maintenance has been asked preform many building washes that include washing alucobond cladding and on one building in particular the dirt had hidden many imperfections that had occurred when the material was scratched while it was being transported to site, this had occurred when a small amount of grit had got in between the stacked panels and rubbed between them as the truck had moved.
If water blasted these panels tend to form a static charge with acts as a magnet for the dirt and this result in the panel getting wet and the dirt on it moving around as its water blasted but not being removed.
Powder coated aluminum
These are simply aluminum that has had and electric current run through it while being covered with powdered type coating which becomes liquid upon contact with the electrified aluminum and forms a very strong bond with it.
Many residential apartments’ complexes do not get washed very regularly which can be very bad for these cladding types.
It is common in many buildings that the hand rails and window frames are made up of powder coated aluminum.
These panels are also prone to scratching and in most cases have been pre scratched while still in the process of being transported to the site while the building was being constructed.