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Mold on Porch balusters

user-234256 | Posted in General Discussion on November 28, 2006 11:31am

Hello Everyone,

This is my first time here, so I’ll give you a bit of background.  13 years ago, my husband and I moved into a “Money Pit” in the beautiful Shenandoah Valley in Virginia.  The house was built in 1742 and has been remodeled every year since then (and not professionally, I might add), and we are continuing on in the tradition.  The last big project before we moved in was an insensitive addition, which included a garage, to the old structure; tied all together with a brick facade.  Despite that, it is a lovely place.  Needless to say, I started a subscription to Fine Homebulding then, and what we have learned has enabled us to keep the roof from falling down on us, and it has given us the courage to tear out and re-do.

We added on a porch in 1993.  The decking is pressure-treated wood and has been sealed regularly.  The balusters and railing are wood, the railing painted dark green and the balusters painted white.  They have been repainted every few years.  The area gets sun in the morning and in mid afternoon.  There are no trees shading the porch, although there is a 100-year-old maple nearby.

This fall, for the first time ever, a black mold is growing on bottom rails that were just installed (purchased pre-primed), but not yet painted.  Green mold is growing on all the balusters.  There is more mold on the sides which get direct sun; the side of the balusters facing toward the house have the smallest amount of mold and it seems to be growing from the bottom up.

I tried washing it off with the hose, then with a brush, but no luck.  Then I scrubbed it off with clorox and it looks lovely now.  There are places where paint was scrubbed off, so I will prime and paint those areas.

So, to my questions:  Any thoughts on how, why mold? and why now?  why not years ago?  What should I do to keep this from happening again?

I did read the article in Fine Homebuilding on mold, and that’s what prompted my intention to write.

Thanks so much,

Margaret Ann

Reply

Replies

  1. WayneL5 | Nov 29, 2006 12:17am | #1

    Welcome!

    The bleach probably did not so much remove the stain as kill the organism and take away the color.  It was the right thing to do because it has to be killed before anything else.

    In some climates the conditions are so favorable that fungus will grow on nearly any surface.  Even vinyl, which isn't a food source, can have fungus on it which feeds on the dirt that builds up on it.

    I've had good results with a product called Woodlife.  It is a clear preservative.  After your wood is thoroughly cleaned (with bleach and perhaps a bit of detergent -- never use ammonia or acids with bleach) and dry, coat it with Woodlife, then prime with a mildew resistant primer.

    You may have mildew instead of mold.  I'm not clear enough about the difference to risk trying to describe it here in public.

    1. user-234256 | Nov 29, 2006 12:53am | #2

      Hello everyone,

      Thanks for the suggestion, WayneL5.  It's so strange that it would happen this year, with 13 years of nothing (and we are officially in 7th year of drought, so it's not over moist).  It seemed to me that the black stuff on the primed wood is mildew, and the green stuff on the painted surfaces seems to be the kind of mold that I'll see growing in stagnant water -- a really bright green.  Also the painted wood trim of the windows in the same area is mold-free.

      Would appreciate knowing if anyone else has encountered anything similar.

      Thanks,

      Margaret Ann

       

      1. BryanSayer | Nov 29, 2006 01:30am | #3

        I thought the bright green stuff on stagnant water was algae. Which I think can appear on roofs and such.

        1. user-234256 | Nov 29, 2006 02:47am | #8

          Hello everyone,

          BryanSayer, you're correct -- I don't think it's really algae, but is the same brilliant green.  The area where the porch is located is not damp, and there isn't growth on window trim or on the pressure-treated deck of the porch.

          Thanks,

          Margaret Ann

      2. calvin | Nov 29, 2006 02:07am | #5

        Margaret, could you please fill in your profile.  If for no other reason than your location and climate, which would be a big help.  You were right on in describing the orientation etc. 

        And welcome to Breaktime.

        Any change in paint previous to the occurrance?  And were the new pcs sealed up on all sides, cuts included?

        thanks.A great place for Information, Comraderie, and a sucker punch.

        Remodeling Contractor just outside the Glass City.

        http://www.quittintime.com/

         

        1. user-234256 | Nov 29, 2006 02:51am | #10

          Hello everyone,

          Calvin, there were no changes to the paint prior to the occurrence, and the new pieces of primed wood were primed on all sides, including the cut ends (my husband is very insistent on that -- we set up sawhorses in the garage and everything gets primed before it goes to the worksite).

          That's why this is so strange -- the area gets sun and the side facing the house (which would get no direct sun) is the side with the least amount of mold.

          Thanks,

          Margaret Ann

      3. VaTom | Nov 29, 2006 02:27am | #6

        Welcome to BT neighbor.  Albemarle here.  Why you had no mold for the last decade is a mystery to me, unless your paint had an herbicide that finally broke down.

        What isn't a mystery is the only surface I've ever seen that absolutely won't grow mold.  Boat hull paint.  Very expensive but wears like iron and will not grow mold.  I've used it on patio furniture for a client.  Furniture lives outside always, unprotected, and zero mold.  Not a user-friendly product, read the MSDS. 

        Molds need food, above 50% relative humidity, and warm temps.  Virginia's a great place for it.  I tend to put copper on exterior wood, dislike paint maintenance, and copper isn't bad for mold growth.PAHS Designer/Builder- Bury it!

        1. user-234256 | Nov 29, 2006 02:57am | #11

          Hello everyone,

          VaTom, you're just over the mountain, so you are familiar with the climate.  I used PPG paint until no one locally stocked it, then went to the Olympic premium.  Don't think any of them had a herbicide included.  The railing was painted every 2-3 years.

          By the way, my grandfather manufactured paint, and my father grew up working in the business.  He ended his working career in a high-up position at PPG Paints.  He had no explanation for this!

          I don't think I'd be able to use the boat hull paint, but will suggest it if I can get a relative to visit who is interested in doing a little painting...

          I'm not familiar with copper on exterior wood, other than the copper post caps that are so popular these days.

          Thanks,

          Margaret Ann

           

    2. kate | Nov 29, 2006 01:43am | #4

      Mold & mildew are the same thing -

      1. user-234256 | Nov 29, 2006 02:48am | #9

        Hello everyone,

        Kate, thanks for that information -- I was afraid I'd have to have separate remedies for the black and the green!

        Thanks,

        Margaret Ann

  2. Shep | Nov 29, 2006 02:31am | #7

    Have you recently mulched any areas near the porch?

    Mulch will sometimes carry molds that can spread to other areas.

    I recently had a customer that had mold spores from mulch attack his Porsche's paint - it showed little black specks over the car.

    1. user-234256 | Nov 29, 2006 02:59am | #12

      Hello everyone,

      Shep, that's a good idea.  Now that I think of it, though, I have just the opposite situation.  I used to have boxwood in front of this porch, but it has been moved out.  Right now there is just an area with flowers and groundcover -- no mulch has been spread this year.  I will keep that in mind for when we re-do that planting area.

      Thanks,

      Margaret Ann

  3. calvin | Nov 29, 2006 03:39am | #13

    So other than a paint brand change, the only difference from the previous trouble free years is the new bottom rail (factory primed, not painted.  The balusters are showing mold at the bottoms-from the connection of the new rail and up.

    edit:  Any regular watering in the vicinity from an irrigation system-spray?

     

    A great place for Information, Comraderie, and a sucker punch.

    Remodeling Contractor just outside the Glass City.

    http://www.quittintime.com/

     



    Edited 11/28/2006 7:41 pm ET by calvin

    1. user-234256 | Nov 29, 2006 04:03am | #14

      Hello everyone,

      Calvin, are you on to something?  Something not quite right with the new bottom rail?

      No, no irrigation -- we're in the country, and if it can't survive on its own, it won't growing here!  I do have a terrific collection of attractive weeds -- er, I mean native plants. 

      This is what's so strange -- no additional moisture, nothing changed except that bottom rail.

      Thanks,

      Margaret Ann

      1. calvin | Nov 29, 2006 04:20am | #15

        Was the bottom rail treated wood?

         A great place for Information, Comraderie, and a sucker punch.

        Remodeling Contractor just outside the Glass City.

        http://www.quittintime.com/

         

        1. user-234256 | Nov 29, 2006 04:26am | #16

          Hello everyone,

          Calvin, no the bottom rail was not treated.  It was factory-primed and I primed the cut ends.  It's been installed just a short time, just haven't had the right combination of weather/time to get it painted.  This weather in the 60s and 70s at the end of November has been wonderful for getting outdoor stuff completed before winter hits.

          Thanks,

          Margaret Ann

           

          1. Bob_the_cartoonist | Nov 29, 2006 04:41am | #17

            I built my own porch and did it very carefully.  It rotted in the lowest spots and I took out the wood and replaced it with PVC.  No more problems, mold mildew, etc.  I only trim anything now with PVC trim..

          2. user-234256 | Nov 29, 2006 02:25pm | #18

            Good morning everyone,

            Bob, had not considered that -- will have to see what's available in our rural area.  If this is going to be a recurring problem, using vinyl might be necessary.

            I had occasion to visit an elderly friend recently; his porch has been in place for the past hundred years, with just an occasional painting.  It is shaded by trees and sited so the house shades it from direct sun.  I would have thought from the location that his porch would have had mold, but when questioned, my friend said it had never happened to him.

            Thank you all for suggestions, I'm going to complete the painting this time and see what happens next.  I'll keep you posted.

            Thanks so much,

            Margaret Ann

  4. User avater
    Matt | Nov 29, 2006 03:27pm | #19

    Most exterior paints contain a small amount of mildewside (sp?).  If you go to a professional paint store you can get mildewside (if that is the correct term) in a small bottle that can be added to your paint for more protection.  

    It sounds like maybe the root of your problem is the new bottom rail?  If possible, I'd contact the manufacturer and tell them what you think of their preprimed products - not that it would likely help you now, but who knows, they might listen, or even "throw you a bone". 

    1. user-234256 | Nov 29, 2006 04:01pm | #20

      Hello everyone,

      Matt, thanks for the tip about the paint additive -- I've known about an insecticide additive (useful here because we have wasps and carpenter bees), but not one for mildew.

      I will let the Home Depot and the manufacturer know -- who knows?  they might throw me a bone!

      Thanks,

      Margaret Ann

       

      1. User avater
        Matt | Nov 29, 2006 04:16pm | #21

        Read the other (current) thread here at BT called "Missinformation at hone store" (or similar. :-)

        1. user-234256 | Dec 02, 2006 02:26am | #23

          Thanks, Matt

           

          Margaret Ann

      2. Snort | Nov 29, 2006 04:16pm | #22

        Margret Ann, if the bottom rail is newly installed, and factory primed, mayhaps the primer is oil-based, making an amusement park for mold. Or, the primer doesn't have mildewicide?We live in a white house in mold central, next painting, I'm taking in a mold sample and having it matched<G> "I am the master of low expectations." Georgie Boy, aboard Air Force One, June 4, 2003

        1. user-234256 | Dec 02, 2006 02:29am | #24

          Hello Snort and everyone,

          Good point -- I don't know and will check at the store.  I had supposed it was a latex/acrylic primer.  I may have to do the same and get the mold "typed" if this happens again.  I'm still clueless as to why I had 13 years with no mold and now this!

          Margaret Ann

           

           

          1. Snort | Dec 02, 2006 04:32pm | #25

            If one is to believe the mold article in the new FHB, building materials have become much more delectable...we have to rethink those moldy oldies<G> Oh God said to Abraham, "Kill me a son"

            Abe says, "Man, you must be puttin' me on"

            God say, "No." Abe say, "What?"

            God say, "You can do what you want Abe, but

            The next time you see me comin' you better run"

            Well Abe says, "Where do you want this killin' done?"

            God says, "Out on Highway 61."

  5. VAVince | Dec 02, 2006 04:57pm | #26

    Welcome,

       I just completed a 2 1/2 month project in Lexington. It seemed to have rained at least once a week during that time frame. We had one down pour about two or three weeks ago of 3" of rain in a six hour period. It has not seemed to be a wet fall because of a lot of warm weather and sun shine. I also noticed that the Shenandoah River is full of water for the first time in a long time. By the way Rockbridge County is very beautiful.

       I have noticed my deck rails(I live on the east side of the mountains) are covered in green this year. Hope this helps.

    Happy Holidays



    Edited 12/2/2006 9:08 am ET by VAVince

    1. user-234256 | Dec 02, 2006 06:13pm | #27

      Hello VAVince and everyone,

      There must be something going on if your railing is green, too!  As to climate -- we are in a "Pocket".  We live along the South River, but a high cliff is between us and the river, so only hear the river occasionally.

      Our weather is very different from Lexington -- higher elevation figures in, I expect.  Our seasonal changes are a week or two behind Lexington.  In the winter, the Route 11 area and Lexington will have an incredibly beautiful ice storm, leaving the trees hung with jewels, while we have a misty rain.  It's cooler here in summer, and we don't get the rains unless they come directly up from the south, as we are protected by the mountains when the storms come from the east or west.  We got less than 1/2" when Lexington had the deluge in the fall.  Our river is full, but the water is from Augusta County coming south -- they, too, had lots of rain in the fall. 

      Yesterday, we had about 1/2 hour of gentle drizzle; however, my husband reported that the rest of the area had driving rain off and on all day long (he's the mail carrier and Montebello and the Blue Ridge Parkway are included in his route).

      I base my degree of wetness for our area on the output of two springs -- they were dry last year, and all of this year, but now do have a little water in them.  Folks with shallow wells in the area have had to have new wells dug.

      Guess I need to check on whether a really cold winter will kill the mold so we can start fresh in the spring!

      Thanks,

      Margaret Ann

       

       

       

       

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