Can you pressure wash render ? The short answer is yes you can. However-, be aware -there is a real danger you can easily cause damage.
A pressure washer is a very useful tool cleaning outdoor spaces, rendered walls included. But using a pencil ( zero degrees) nozzle , or a turbo ( dirt blaster type ) nozzle, can permanently damage a delicate surface like K rend, tyrolene, Weber , and monocouche type surfaces.
So how should you clean ‘through coloured’ ( no need to paint ) rendered walls?
Most soiling of one coat rendered walls is organic staining caused by algae growth. This is usually green algae , red or black. This is absolutely nothing to worry about and we can clean this off easily with biocides, sodium hypochlorite and water – using a low pressure steam clean. Results are usually excellent if this organic staining has been left only a year or two. On occasions where the biofilm has been left to grow for ten years plus I have seen the render being permanently stained and even etched away in places.
Some of the other staining we see is caused by pollution ( carbon from exhaust deposits ). This is the most tricky one to remove and requires an acid.
Rust stains caused by rain water running down metal fittings are generally easy to remove with a mild acid (again -if not left too long).
Water marks caused by rain water running down window reveals can provide the most problems , especially when the minerals from cement leech out. The worst case scenario is we have to paint the walls but this is rare and usually on retaining garden steps where no membrane was installed between the soil and the wall.
The others problem can be access. We have equipment to work from the ground up to around 3 or even 4 storeys. If required we can bring our scaffold tower or cherry picker.
The first step is send us your details including some photos and we will advise
So – Can you pressure wash render ? We can ! Contact us here
