Hardie board with no SH

Hey guys so I was asked to come look at a job today and was wondering if this was a good idea/ would work. It was a small 1,600 sq newer condo. The complex is doing a lot of construction and paving etc so the homeowner wants their house washed. There is no mold or mildew just dirty from dust and dirt. The front of the
House is hardie board the other sides are vinyl. I plan on hitting the vinyl with my normal HW mix (business as usual) but for the hardie board I was thinking of using just surfactant. It figured why risk running into issues with it reacting with the sh when it looks like all it need is a good rinse. Has anyone ever done this before not used SH just water and surfactant?

Question, while you were there did you do a test spot on the Hardie siding with just surfactant?

No. I understand I’m probably going to get in trouble for even suggesting it lol I understand it’s unconventional but it’s really a small area and just dusty/ dirty and to be honest I’ve never done hardie board I do mostly vinyl. So I assumed instead of doing a test spot and possibly running into issues it might be possible to just clean that small section without SH

If you ever have reservations the first thing you should do is a test spot in an inconspicuous area. To answer your question, yes, soapy water will clean dirt from Hardie siding. I’ve done exactly that many times.

Thank you, under normal conditions ( not letting it dry etc) could surfactant ever have negative interactions with hardie board or other painted surfaces?

Not in my experience. Again, do a test spot.

The ole Texan has good advice here. A test spot isn’t just to rule out adverse effects but it will help you figure out what will & what won’t work in the future when you run into a real challenge on the fly since every property is unique. There is very little hardy board around here but I’ve had great luck with it. No weep holes, no overlaps, easy as it gets.


or a test spot with SH…to alleviate any concerns…I mean, you were there anyway :man_shrugging:

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We have this richie rich area called Norton Commons and every house has Hardie board. I did one last year with surfactant-only and they were happy I was looking out for their property. They have this ‘tunnel effect’ wind and dirt just piles up like crazy.

In places with lots of dirt/pollen/bugs, I often wash Hardi with just Simple Green and warm water. Has always done fine.

Maybe check out Simple Cherry from PressureTek? Never used it, but here’s the link and description:

“Simple Cherry is a multi-surface cleaning product that is safe, effective and simple to use! Simple Cherry is sold in 10LB packages. Simple Cherry’s proprietary blend of surfactants and water softening agents make it rinse easily without harsh side affects on glass and painted surfaces. Simple Cherry’s surfactant package is stable if used with chlorine. Simple Cherry is infused with a strong cherry fragrance. Simple Cherry is safe to use on most surfaces including painted surfaces, vinyl, aluminum, awnings, wood, & more. Not only can Simple Cherry do all this it can do it at an effective price”

I’ve done plenty of hardi board homes and always use SH with no issues. If it looks pretty clean, I go lighter with about a 40:1 ratio instead of my normal 20:1. I’ve even done red, blue and green hardi board houses with no issues. I just do the lighter 40:1 and an extra rinse with those colors. Even when it appears there is no organic growth, you can see there is when the hw mix hits it. I won’t wash a house without sh. Just test to make sure it’s not organic paint, then wash it.

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Yeah but why waste SH on a house that’s just dusty?

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IMO, there’s always some level of organic growth present.

More important in my case, standardization of processes is critical when you have teams going out there to wash houses. It’s far from easy to have many crews that can make those sort of judgments from job-to-job. Limiting variables makes for efficiency and simplicity for them to go do what they do best, and make clients as happy as can be. I included the $20 in the standard pricing, and I’ll probably create more than $20 in inefficiency trying to make them do something they aren’t used to doing (or at the very least it isn’t worth saving the $20 trying to do it IMO). When you’re out there doing the jobs, that’s probably a different story, but may not be either…

If I did a whole house at 40:1 I’d use about 1 1/2 to 2 gallons of bleach. As stated above and what I said earlier, even if you can’t see it, there is always some level of algae and/or mold on the house.

For reference here is a picture of the condo. It’s attached to another condo so it stops
At that garage. The side and back are vinyl

It’s grey, should be fine with HW mix. I did see mild streaks one time with a light blue Hardie.

Personally, if it’s painted and there’s no mold or mildew, I would just use water and a soap. Collect my check and go.

There’s always some level of mold and mildew…even if it’s not quite reached the visible stage just yet. I’m not trying to wash something and have the mildew start to be noticeable in a couple of months. People want to make that argument about their brick front all the time… Sorry, we wash it all or not at all…

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