Mold on my metal building

[radioman]

first off -- I doubt its mold/fungus. You said its on north side. moss/algae grows on stuff on north side. any trees on north next to building? A stiff brush and algaecide/mosskiller will work.
now on the north side, does the roof drips on that side or does it goes into the peak of roof? If it drips on northside, do you have a gutter? If not, whats the roof really looks like up close? You might have moss/algae there too. You might want to do two things from this point if the prevent point is true. Open up the northern tree to let more light in. add copper or zinc strips to northern side of roof to prevent reoccurance.

 

[rrrkkk]

Ever tried standing on a sloped wet metal roof (just saying)

 

[woody]

I am getting ready to spray my house last done about 5 years ago. last time I uesd bleach and water brushed it on with a carwash brush and rinsed. this time I am going to try something a little different I have a paint sprayer I will use to put the bleach mixture on with and a pressure washer to take it off.

 

[teejk]

Ever tried standing on a sloped wet metal roof (just saying)

I know somebody that tried once. His broken back is healing nicely from what I hear and he no longer wears the head/neck brace. He is mid-50's so it will never be perfect again.

 

[teejk]

first off -- I doubt its mold/fungus. You said its on north side. moss/algae grows on stuff on north side. any trees on north next to building? A stiff brush and algaecide/mosskiller will work.
now on the north side, does the roof drips on that side or does it goes into the peak of roof? If it drips on northside, do you have a gutter? If not, whats the roof really looks like up close? You might have moss/algae there too. You might want to do two things from this point if the prevent point is true. Open up the northern tree to let more light in. add copper or zinc strips to northern side of roof to prevent reoccurance.

I've owned several houses. When I built what is hopefully my last one, I insisted that the lot be cleared to keep any stucture out the shade on the north and west sides. Decks on the north side attract what I think is algae. Get that slime wet and good luck flipping your pork-chops without finding yourself seated on the deck.

 

[schmism]

TSP works well as a solution to be sprayed with a pressure washer.

 

[brin]

The big box stores sell a bleach that does not hurt your lawn or plants....ask them for it...I forgot what it is called...

Be very careful mixing anything with bleach...like ammonia for sure....it can kill you dead as a stepped on mouse...no kidding...

 

[TNhobbyfarmer]

Thanks to everyone that responded. I am sure I used the wrong name for the growth. It is most assuredly algae, not mold/fungus as I called it in the original post. I think I will have no trouble getting it off. Just wanted to get your opinions. Lots of great knowledge here. Why not access it?

 

[cletus99]

Not sure about bleach hurting the paint, but when I lived in Florida I had a house with white vinyl siding and after a couple years it had a black mold on it. I used a pump sprayer with a little less than half bleach and water and sprayed it down. Then went back and used the water hose with a regular spray nozzle and hosed it down. Looked brand new when finished. No scrubbing at all. Just have to make sure to wear old clothes you don't mind being bleached .

 

[Deere Dude]

Ever tried standing on a sloped wet metal roof (just saying)

Last year I used a solution I bought from Menards that had a little bleach in it on my pole shed because of the green mold or whatever it was on the walls. I was concerned about hostes and other plants around the building base but it didn't hurt a thing. This stuff came in a 1-2 quart container that you hook a hose to and spray just like a garden hose. It reached easily to the 14'sidewall top. Then I had a medium bristle floor broom hooked to a 12' aluminum swimming pool handle. I sprayed and scrubbed and it came off very easily.

I did the same thing on the roof because the roof of my 36x54 pole shed has a slippery residue on from farmers dust and trees around it. The roof was verrrry slippery on the uncleaned portion. Once I cleaned one side I was walking along the peak on the dirt side to the other end and hit a patch of over-spray. I went down like a sack of potatoes and slid on my rear to about 4' from the drop. That is when friction took hold. All along i was trying to figure I was going to land this thing, but got lucky and stopped, but got chewed up from the screws.

Light bleach solution works white and green painted steel panels very well. Good luck.