I recently got a request to wash a very expensive house covered in dark blue Hardie board and my first reaction was to ‘run away’.
I explained to her about pigments used and potential for spotting etc, so she’s pretty bummed about it but it got me thinking. What can we safely downstream that will kill mildew and algae on the white trim but not harm the paint? Any updates on some miracle chemical?
Do a test spot. If the house has factory painted Hardi I doubt you have to worry about the paint changing colors. That’s a particular paint code from Sherwim Williams.
I do test spots, factory paint I’ve not had any issues myself. Just check reactions first, do lower %Sh mix.
Not the house but here’s the color.
I just did an olive green house this week and have done a few blue that color recently. Prewet the siding, light .3-.4 mix and rinse before it dries and rinse and a lot. I’ve never had an issue.
I thought basically everyone here said stay the hell away from the blue colored houses? Hell, I thought they said stay away from dark houses period.
Walk away. Sherwin williams has the most issues because they sell the most paint. It can happen with other paints, even dark colored vinyl. Were you drinking while I was typing lol
Ok…what?
He must’ve had one too many Cheerwines before posting.
Lol, went back and corrected it
I stepped away from this one, referred her to a more established company. Last thing I can afford is to repaint a million dollar house.
I do a fair amount of Hardie board with no problems, but I was nervous about this dark red one I did today. Went behind hvac unit and hit a spot with some straight SH and let dwell for about 15min. No problems, but still went with about a .5% mix since gutters and trim only things really dirty. Cleaned up fine with no problems what-so-ever.
LOL, neighbor came over to get card after walking out to get in car and seeing this.
Nice! You’re braver than I am lol.
That’s almost the exact shade of red as the one I did that faded and came back. It was older and oxidized though.
This one is about 10 years old, had just a little oxi but not bad. Houses close together, so doesn’t get a lot of sun except in the rear and more faded there. Took a boatload of before pics to CMA.
I do just what you did. I usually have to hit gutters and soffits twice because of lower SH. No issues though….
Since I’ve never seen Hardie board get nearly as bad as vinyl, I go even lighter, .3-.4%. I lightly mist it first, then hit it and rinse right away and rinse excessively. On average I probably spend an extra 15-20 minutes on those color houses just rinsing. I’ve done dark blues, olive greens, reds, you name it. Been doing this for going on 5 years and have yet to have an issue with any house. Maybe what I do is a bit overkill, but I rather spend an extra 20 minutes and know I won’t have an issue.
2 year old hardie, really dirty from landscaping and dust from cutting stone and concrete.
Best way to wash effectively while avoiding issues? Also, on well water and black fascia etc, will probably try Rick’s @Racer recommendation of rinse-aid?
Sometimes it’s ok to say no thanks. This would be one of those times
