Vinyl siding vs. mold...

Hello all -
Why is it that houses with vinyl siding seem to get buildups of algae or mold on the vinyl?
I don't see the problem with wood or aluminum siding. This old house I'm in (1911) still has its original stippled wood siding (I -think- it's wood, have wondered if it could be asbestos-based). The paint is at least 34 years old, but still -- no mold.
Yet that stuff takes to vinyl like it belonged there. Any way to keep it under control (other than washing or cleaning it off)?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Never noticed it. My house has vinyl siding and while the foundation on the north side has had some mold, the siding above it never has. Never took any preventative measures either. I may wash the house down every few years if the rain does not do enough, but that is all.
Spray it down with a solution of 1/3 vinegar and that will kill any mold spores. Strong bleach should not be used.
Trim any bushes and tree branches nearby too. Darkness and moisture make a comfy home for mold.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
alt.home.repair:

My house has vinyl siding, and the north side, which is also very shady in the summer, does get a little green mold. I just wash it off with some bleachy water every year or two.
What's wrong with bleach in this situation?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 20 May 2012 02:33:07 -0400, Nil

Strong bleach or undiluted bleach should not be used. Diluted should be OK. I'd go with at least 8 qt of water for every 1 qt. of bleach.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I use a product called Jomax House Cleaner and Mildew Killer
Mixing instructions are:
3 1/4 quarts Water 2 1/4 cups Bleach 3/4 cups Jomax
It works very well on the mold I get on my vinyl siding. Spray it on, let it sit a few minutes, hose it off.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 5/19/2012 9:00 PM, John Albert wrote:

I've got it on aluminum siding on North side of house. Easy enough to wash off, where I can reach it, and a little dilute bleach will not hurt but in shaded sections it reappears.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.