Cleaning Omaru Stone

smyrnia, Mar 12, 3:50pm
Hi folks
Is it ok to waterblast an Omaru stone house.
Or is there a better way of getting the "mold" etc of the outside of it ?
Thanks

lythande1, Mar 12, 4:03pm
It's just limestone not special.

wine-o-clock, Mar 12, 4:30pm

maclad, Mar 12, 4:50pm
Using a moss and mould killer sounds like a good option but they can take months to work, but then the results last a long time. So if you have the time give it a go and then do the sealing thing. Limestone is prone to getting green mould. I sprayed my lichen infested roof with this 5 years ago, took almost 12 months to disappear but has never come back. Retreat again before you really need to as Moss and Mould killer keeps working for a while after it is used discouraging new growth.It has a residual effect and the ingredients in it are found in so many of your day to day cleaners, eg. laundry powder, detergents, shampoo soaps and so many more, so more than likely you are already in contact with the chemical, like it or not.

golfdiver, Mar 12, 5:27pm
Most of what you typed there is nonsense. The ingredients are found in disinfectants not laundry powder or shampoo. After about 60mm of rain there is no residual chemical left to have any effect at all. How do you think houses that use rainwater for drinking get on when they treat their roofs?

smyrnia, Mar 12, 6:02pm
Thanks for the answers so far folks

cagivachick1, Dec 9, 7:16am
wire brush or file it back to clean and seal it with a good quality sealer