Michael Roback wrote:
I just finished remodeling a house. The outside deck has sat without a
finish surface for about 2 years. A rubber membrane surface was painted on
the plywood deck and then an aggregate coat was floated on top. Well the
guy who did it did not tape the seams properly and it started to leak a few
weeks ago with the bad rains in southern california. I have been waiting
for the deck to dry out enough to bring someone else in to finish it. Well

Rubber coated plywood deck? Why? What is under it?

the other day I noticed some discoloration under the deck on the plywood and
thought it was water stains but it is dark and probably is mold or fungus
and I am not sure what to do. I assume it would be a good idea to remove it
if possible prior to the topside of the deck being finished so that if there
is any mold between the joints of the plywood it can be treated if possible.
I have read that bleach doesn't really do a good job at removing or killing
this. It is now wet as it rained today. I don't want to infect myself with

If it got to your deck, it got to you. Mold and mildew float around
everywhere.

the spores. Is there anything I can spray on it that is safe to use? I
have maybe a half of a dozen pathches or streaks. One area is maybe 2-3 ft
square the rest are smaller. But if I wait until the rains stop and things
dry out to deal with it it may have grown alot more. Is it better to deal
with it wet or dry? To tear the deck down and incur the cost of rebuilding
would be a financial nightmare for me right now. Once the mold is removed
or treated is it a pretty good bet that it will stop growing. I don't want
dryrot growing in a deck for obvious reasons? And I was considering govering
the underside of the deck with stucco at some point. I guess I should paint
and leave it open to observe it over time? Any adivice or help would be
greatly appreciated.


Is the area beneath the deck open to circulating air? That would
probably help it dry out once it stops raining. Don't worry about the
mold under the deck unless you are living there. Worry about falling
through the rotting wood when you walk on the deck )