Hardie board oxidation?

I have a customer who had his rental washed and it looks terrible. Big grey spots and streaks left on the home. I am stopping by tomorrow to run a sample test of my HWing mix. The problem is I can not tell if the other guy faded the old paint off in certain areas and thats what I’m seeing or is it just a poor cleaning job and it has been left dirty.

When I run my fingers over the exterior I’m left with a large chalk build up just like oxidation. The owner knows if its ruined he will paint anyway so I’m cleared to test and see. If he in fact needs it painted won’t he need the wash to prep for painting? If so is there a different process to prep? Is oxidation common on Hardie plank?

I will have pics tomorrow. Thanks

Run far away and quickly. No need to bring headache on yourself

Thanks for the input, I brought a builder over and it appears that a terrible quality paint and prep was done. The first pressure washer simply removed already damaged areas. I approached with caution because of your advice, Thanks again.

Like this?

This was after a “soft wash” which just removed the mould - not what the owners actually wanted. I just applied my usual house wash mix and then brushed it with a large soft brush - it’s one of those jobs you just have to stop thinking about and get stuck into.



Anytime I have a house with stucco, hardi or vinyl I have a discussion about oxidation before I start and make it clear that that if it has oxidation it is his problem and if he is not willing to accept that, I walk away. Not only can it streak but if the customer has an awning, the first time it rains the awning is going to get oxidation on it and he’ll be calling you back.


Hey we all hate to leave money on the table and walk away, but sometimes…

That’s good advice!

Thats exactly what I had to do. He liked my honesty and is using my company for two smaller services.

I had to hand wipe a town home last year that was oxidized. Didn’t see it while I was doing the bid.-Then washed it—and had to come back after customer had complaints.My first experience with it in 12 years of washing. A nightmare–yes…
It caught me by surprise. I can spot it now. I’ll never get involved with it again. As the other guys here say. Walk away. Or charge a couple thousand dollars to hand wipe it with a bleach water mix. That’s what I did on the vinyl siding.Not sure if that would work with Hardiplank. * Remember too.Once you set up your equipment and try to be a hero to any situation ,thinking you can resolve anything. You then become involved. I will never even set up my equipment and try anything when it’s dealing with oxidation. "Just walk away "