Why Does My Composite Decking Have Black Splotches?

composite%20deck%20board Why Does My Composite Decking Have Black Splotches?
So you spent your hard earned cash on Trex or one of the other big name composite decking brands. You were sold on the idea that this product was low maintenance. No need for staining and the deck will never rot, splinter or have problems with bugs.
But now you’re ticked off.
That beautiful, smooth composite decking has black marks all over it. Dark splotches that mar the pristine finish you paid for. Stains on the face of an expensive home improvement project.
Your frustration and fury are rising. And you’re not alone.


There are disappointed people all across the country, homeowners up in arms about the appearance of their composite deck after only a few months. They thought they had paid for a no maintenance product. But now they’re finding themselves scrubbing, washing and cleaning the deck surface to get rid of the ugly black marks.
Why?
Those black marks are actually mold. The official Trex website states that a “build-up of pollen and other debris can support the growth of mold” and will require semi-annual cleaning. Um, that means twice a year people! And you thought this was maintenance-free, did you?
There are some warranty claims and potential law suits being pursued right now (google “Trex black marks” and you’ll find a bunch of forums and links mentioning them). But since the warranties of these composite decking companies do not cover mold or mildew, it doesn’t look good for the homeowners.
What Can You Do?
Wash your composite deck in the spring and fall with a wood cleaner product. It’ll only take an hour or so and will leave the surface looking clean and smooth… for a little while.
Change your expectations. Composite decking is found outside where the weather, sunlight, dirt, dust and all sorts of other debris are floating around freely. Maybe a little wash now and then isn’t too much to ask for. Maybe a few black marks are understandable and can be lived with.
It’s up to you, really. But with lower, more realistic expectations of composite decking your blood pressure may drop a few notches and you can actually enjoy the backyard a little more.
photo courtesy of Joe Shlabotnik