Mold on Hardy Board

[Rick Babulski]

My daughter in Raleigh has what appears to be mold on the exterior of her house on the shady side...(Don't know if it's mold or mildew or somethimg else) look at attached pictures. What can be cause and what is the cure...anyone????
Thanks

[Jerry Peck]

I'm afraid what you may be seeing is the tip of the iceberg.

Fully agree with that.


It looks to me like the moisture issue is behind the siding.

Agree with that too.


that looks like some sort of pressboard and it looks shot.

Looks like hardboard siding (Masonite, LP, etc.), not HardiePlank, agree on that too.

[Richard Stanley]

Probably perfectly natural. Moss grows on the north side of trees.. no sunlight to kill the algae. Power wash the wall or use a light clorox/soap/water solution with a brush - - then wait until next year and do it again.

[Vern Heiler]

Probably perfectly natural. Moss grows on the north side of trees.. no sunlight to kill the algae. Power wash the wall or use a light clorox/soap/water solution with a brush - - then wait until next year and do it again.

And have replacement boards on hand for when you have finished:D

[Scott Patterson]

Fully agree with that.



Agree with that too.



Looks like hardboard siding (Masonite, LP, etc.), not HardiePlank, agree on that too.

Yep, that is MDF or hardboard siding.

[Matt Fellman]

Pressure washer???? Better have a spoon handy to pick up the oatmeal....

Sorry to say it but that is totally failed siding.

[Brandon Whitmore]

I tell my clients to stay away from pressure washers, and tell them to not let anyone else pressure wash their roof or siding. How many of you have seen contractors blasting away at roofs and siding systems at an upward angle from way too close? My neighbors house was just painted. The painters pressure washed the house first. They were spraying at an upward angle, and were maybe a foot away. I'd hate to see what the WRB and window flashings look like.

Judging by those pic's, I think that the siding system is shot. Bigger roof overhangs would most likely have prevented all of this damage.

[Richard Stanley]

Oops! I just answered according to the original question re: Hardy
On the other hand ... The power washer could expedite removal of the crap.

[A.D. Miller]

It is not a James Hardie product, and that is not mold.

It is a hardboard siding product that has failed, as it was destined to do. The wood-destroying fungus is now utilizing it for what it is worth.:D

[Jerry Peck]

My first thought was the title: Mold on Hardy Board , which should have been "Mold on Hardly Board" as that hardboard is "hardly a board". :)

[A.D. Miller]

My first thought was the title: Mold on Hardy Board , which should have been "Mold on Hardly Board" as that hardboard is "hardly a board". :)

JP: If hardlyboard.com is not taken, perhaps you should do the honors.:D

[Robert Dalga]

That is just down right nasty looking!!!

[Scott Patterson]

I tell my clients to stay away from pressure washers, and tell them to not let anyone else pressure wash their roof or siding. How many of you have seen contractors blasting away at roofs and siding systems at an upward angle from way too close? My neighbors house was just painted. The painters pressure washed the house first. They were spraying at an upward angle, and were maybe a foot away. I'd hate to see what the WRB and window flashings look like.

Judging by those pic's, I think that the siding system is shot. Bigger roof overhangs would most likely have prevented all of this damage.

I wish I could find the pictures of an EIFS house from several years back. The owner pressure washed the EIFS to get the "dirt off". In several areas he took it down to the EPS foam and even blew off a couple sections of foam under a window. It was a hoot! He called me out to his home so he could join a class action lawsuit!

I laughed so hard, I had a hard time even charging the guy just to tell him that he was an idiot!

[Brandon Whitmore]

I wish I could find the pictures of an EIFS house from several years back. The owner pressure washed the EIFS to get the "dirt off". In several areas he took it down to the EPS foam and even blew off a couple sections of foam under a window. It was a hoot! He called me out to his home so he could join a class action lawsuit!

Now those pictures, I'd like to see. I don't understand how some people lack what should be common sense.

[Mike Schulz]

That is Composite board AKA Masonite. We have allot of it around here. We also have osb siding which rots pretty much the same way.

Water splashing off that propane bottle and lack of gutters probably caused water splashing into the wall.

They make cement fiber with the same profile so replace with that as needed.

[Matt Fellman]

As I'm sure you all can relate to, I often find myself at an inspection looking at a water stain or something else and wondering 'how did that happen and where could it have come from' - Then I'll answer my own question as I work or drive through a neighborhood and watch some yahoo spraying his pressure washer straight into his soffit vents or up his siding around the windows.

[A.D. Miller]

Like this guy . . .

[Brandon Whitmore]

Aaron,

He would have sprayed upwards at a steeper angle, but that's the only way he could get the ladder set up. :D

I drove up to a house last where where the builders employee was cleaning his personal house he was selling. The employee was scared of walking on roofs, so he stood at the gutter line and sprayed upwards. I jumped out of the truck and got some great shots of shingles flipping up for the report.