Siding Turned Yellowish After Cleaning...HELP!

[Laurie Grathen]

Washed a house this afternoon with painted masonite siding. The east side only turned a yellowish-tan splotchy color after the wash with cold water and treating with a 25% sodium hypochlorite solution.

Any ideas? We're completely stumped.

 

[Beth]

Was the ratio the same on all four sides of the house for the solution? I know bleach (sodium hypochlorite ) can have a yellowing effect if too strong and not rinsed well. Maybe more rinsing or have you rinsed the heck out of it already?

Also, what do you know about the paint that's on the side? What kind is it? How old, etc.....

Beth

 

[johny]

It happened to me once when i used pool bleach on a very old ,white vinyl siding.It only appeared on one side.I left it as is,but somebody on the board i remember suggested to try some light acid solution.Like oxalic to bring ph back to normal.I hope somebody else replies to help you out.
Johny

 

[Laurie Grathen]

Extractive Bleeding??

Ok, maybe I didn't say it correctly. Using regular household bleach (5.25% active ingredient), the guys put 1 part in to 3 parts water. It's the same mixture they've been using for 3 years to treat mold and mildew on homes with no problem.

And if it was the sodium hypochlorite that did it, why only on one side of the house? There's gotta be some other explanation. I can't believe it was anything we did. What other kinds of things cause this to happen?

After some research last night, it appears that there are thousands of lawsuits regarding masonite type siding, that wood affected by moisture from behind or improperly prepared painted surfaces does something called Extractive Bleeding which leaves a yellow-orangish stain. Anyone one know about any of this?

 

[Glenn]

Laurie,
This is just a guess now as I haven't ran into this before. I think you are on the right track with the bleeding, but I think it hapened only on one side due to the fact that before cleaning that side probably had more oxidation on it. After cleaning the oxidation off you in effect uncovered an underlying condition of bleeding. I would guess it has been several years since this house was painted and I would explain the process of oxidation to them and suggest that they paint at least that side. How was the lighting meaning what side gets the most sun? I would think this problem would have been the south side, or is it actually a south east side. This is just my best guess.
Good luck Laurie,
Glenn

 

[Laurie Grathen]

All's Well...

[flag]

Randy went back yesterday and, as instructed on the web site explaining extractive bleeding, rerinsed with warm water and sprayed a solution of oxalic acid. Returned almost immediately to it's normal color. So...

it appears that the finish had probably failed, exposing the wood, which was still full of the tannins and stuff wood's full of. The sodium hypochlorite changed the chemistry of the wood, just like in decking (although I've never seen quite that color on a deck!) and we returned the chemistry back to normal with the acid.

Magic. Thank goodness we didn't have to call on our liability insurance.

Thanks for all your help and input.

Laurie and Randy
All American PowerClean
Lake of the Ozarks, Missouri