Decks, Patios, Porches and Docks - Black Mold Growing on Recently Stained Deck
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jaymes
08-21-06, 08:41 PM
I have a deck that is less than a year old and which has only been stained within the past three or so months. I used Maxum Semitransparent water-based stain by Coronado, but I added a natural bug repellent to the stain that consisted of various oils (i.e., citronella, cedar wood, etc) AND is sold as compatible with my stain.
Part of my deck is under a big pecan tree. I now have many boards that have a thin layer of what appears to be a kind of black mold. It is not sooty and it does not rub off easily.
Any advice on how I can remedy this situation; possibly clean up the deck a little?
Thanks
Jaymes
Part of my deck is under a big pecan tree. I now have many boards that have a thin layer of what appears to be a kind of black mold. It is not sooty and it does not rub off easily.
Any advice on how I can remedy this situation; possibly clean up the deck a little?
Thanks
Jaymes
lefty
08-21-06, 09:34 PM
How well did you clean the deck before you applied the stain? My first guess would be that it's pollen from the pecan tree, especially if it can be rubbed off (albeit with some effort).
jaymes
08-22-06, 03:58 PM
How well did you clean the deck before you applied the stain? My first guess would be that it's pollen from the pecan tree, especially if it can be rubbed off (albeit with some effort).
Like I said, the deck is fairly new; however, I did use a Mill deglazer to clean the deck and it seems to be pretty darn clean when I stained it. I know it's not pollen per say as I waited until all of the pecan pollen pistles fell from the tree before I stained the deck. Again the deck has only been stained a couple of months now. I really think it is some form of black mold and I am concerned that the oils I added to my stain are feeding the mold.
I would like to try and clean the deck with some bleach, but I am concerned with the effects bleach will have on the stain (I don't want to bleach out my new stain and have to restain the whole thing over again... IT IS 1500 sq ft).
Anyone have any input on what a mild bleach solution (or other cleaner) might do to my stain?
Like I said, the deck is fairly new; however, I did use a Mill deglazer to clean the deck and it seems to be pretty darn clean when I stained it. I know it's not pollen per say as I waited until all of the pecan pollen pistles fell from the tree before I stained the deck. Again the deck has only been stained a couple of months now. I really think it is some form of black mold and I am concerned that the oils I added to my stain are feeding the mold.
I would like to try and clean the deck with some bleach, but I am concerned with the effects bleach will have on the stain (I don't want to bleach out my new stain and have to restain the whole thing over again... IT IS 1500 sq ft).
Anyone have any input on what a mild bleach solution (or other cleaner) might do to my stain?
lefty
08-22-06, 07:32 PM
What did you use for decking? My second guess, if pollen isn't the problem, would be the water based stain reacting with the tannun acid in the deck boards. That will leave black spots as well.
jaymes
08-24-06, 10:12 AM
What did you use for decking? My second guess, if pollen isn't the problem, would be the water based stain reacting with the tannun acid in the deck boards. That will leave black spots as well.
I used PT lumber that had weathered in place for over six months (winter) before I stained it. I also used a Mill Deglazer on the deck before applying the stain. The black growth was not there after I stained it back in May. It has only shown up recently (2 months later) with the humid month of August (I'm in GA). It is not a reaction, I am pretty darn sure it is a type of black mold. It is not real sooty, but it is dull like mold.
What I am really looking for is advice on bleach. Does anyone know if bleach will adversely affect my recent stain (i.e., will the bleach bleach out my stain)? If so are there other products that might remove the mold, but not affect the stain? Again this is a large deck and I only have the problem in the area of the deck under the most tree cover (i.e., the shadiest part of the deck). The deck is about 3 ft off the ground at this spot and I have trimmed back some of the pecan limbs to bring more light to this portion of the deck, but what I need to know is how to fix the damage that has all ready been done. Tempted to stain a scrap piece of wood and let it sit for about a month and then try and bleach that to see what it does to the stain, since I can not think of any other solution...
what about TSP? Will that remove mold without affecting the stain?
I used PT lumber that had weathered in place for over six months (winter) before I stained it. I also used a Mill Deglazer on the deck before applying the stain. The black growth was not there after I stained it back in May. It has only shown up recently (2 months later) with the humid month of August (I'm in GA). It is not a reaction, I am pretty darn sure it is a type of black mold. It is not real sooty, but it is dull like mold.
What I am really looking for is advice on bleach. Does anyone know if bleach will adversely affect my recent stain (i.e., will the bleach bleach out my stain)? If so are there other products that might remove the mold, but not affect the stain? Again this is a large deck and I only have the problem in the area of the deck under the most tree cover (i.e., the shadiest part of the deck). The deck is about 3 ft off the ground at this spot and I have trimmed back some of the pecan limbs to bring more light to this portion of the deck, but what I need to know is how to fix the damage that has all ready been done. Tempted to stain a scrap piece of wood and let it sit for about a month and then try and bleach that to see what it does to the stain, since I can not think of any other solution...
what about TSP? Will that remove mold without affecting the stain?