Worst house we have washed. Ideas why?

[tinman 14]

We washed a big house (brick with sood trim and some siding) last week and it was only 13 months old, but very dirty. No green stuff, mostly black. The bleach would not touch it so we basically brushed everything with the gutter cleaner . I even tried the gutter cleaner sprayed on with the wand just to see and that did not work. With closer pressure the top layer would come off but it was still there. And alot of the homes in that sub division looked the same way. Any ideas on the reason? It is as though something was wrong with the paint or the wood underneath when they painted it new. Thanks

[squirtgun 122]

We cleaned a house a couple of years ago that had a similar problem.There was black mold growth under the paint.I threw everything I had on the trailer at it doing test spots to no avail.I even called a couple of chemical suppliers in the industry who felt as though I had done everythig I could.

I hate admitting defeat,but this is one we walked away from.The customer wasn't happy and even less pleased when I refused to be paid for not getting their house clean.

[CLASSICPW 14]

Is the house near an airport or a coal burning power plant? Could be oily residue from jet fuel or the plant. Otherwise I"v seen mold under paint from a poorly prepped previous job. Mainly on wood siding that wears a semi. It's very annoying to keep washing and still see black areas.

[RyanH 14]

We built our home in GA about 16 months ago...already have lots of black stuff on the paint and the gutters are horrible.

Gutter consensus: undersized gutters and roofs with too great a pitch. In GA for some reason they love to build high steep roofs and put tiny gutters on. When it rains, water overflows and carries roof oil with it and streaks the gutters. That's my theory, anyway.

Mildew consensus: we have such huge swings in temperature around here that we hit dew point every night with rare exception. With that much condensation on a house at night and sunlight during the day, siding is a buffet for stuff to grow.

Fortunately, I'm not concerned since I know someone who owns a few thousand $$$ worth of pressure washing equipment and the know-how to use it ;) My neighbors are lucky.

[Beth n Rod 1,279]

Is it in the flight traffic lanes? Could be jet fuel. Needs a degreaser to remove it.

Rod~!

[John Orr 206]

My guess is that your bleach had gone "flat". I have it happen occasionally, due to (I think) the additives I use neutralizing the chlorine. (I use 12.5%) As a matter of fact, I had this happen yesterday. 4 year old house, aluminum trim, vinyl siding. Some green, but mostly black algae on all the trim. My mix was not touching it, changed to a fresh batch and it disappeared.

[tinman 14]

not near the airport. I don't think the bleach had gone flat, as I just got it and used it on 2 other houses & it worked fine. Every house on the street is just as bad.

[PLD 14]

I agree with this thought. I spent 6 hrs and a bunch of degreaser on a 1.5 hr house that was "just mildewed". Turned out to be soot from a trash/fire pit that once existed in the backyard.

Is the house near an airport or a coal burning power plant? Could be oily residue from jet fuel or the plant. Otherwise I"v seen mold under paint from a poorly prepped previous job. Mainly on wood siding that wears a semi. It's very annoying to keep washing and still see black areas.