My husband and I have spent the last four weeks rebuilding our deck. We
decided to go with a cedar surface because we love the natural reddish
colour of the wood.
We nailed the last board in on Sunday evening. Everything was perfect -
straight, flat, lovely golden/rosy tone.
There was a thunderstorm on Sunday during the night. On Monday morning, we
awoke to discover that our lovely new deck has developed mildew. In the
space of EIGHT hours. I kid you not. Many of the boards are speckled with
little black marks, and the top stair tread has a big grey mouldy looking
stain. It's bloody awful.
Is this normal?!? The guy at the hardware store seemed really surprised that
mildew would develop so quickly. What makes it more perplexing is the fact
that the deck is south facing, and has been baking in 30 degree sunshine
during the construction process. We live in a dry climate with very low
humidity. How the hell does mildew develop in that?!
We had hoped to lightly buff the surface with a sander, then finish off with
a natural coloured UV protection oil. What we're worried about now - how
long do we have to wait after cleaning out the mildew, and will the mildew
grow back before we get a chance to sand and stain?!? I would have thought
no, but I also didn't think that mildew could appear in the space of a
Were we supposed to treat the boards with the protective oil on all sides
before we nailed them down?
Also, I've noticed that some of the boards are developing hairline cracks.
Is this normal for cedar?
We thought we had everything in hand, but the appearance of the mildew has
really thrown us off course. I'm beginning to wonder if we haven't just
thrown a huge amount of money down the drain :-(.