Decks, Patios, Porches and Docks - Trex Decking Butted up against each other

I was taught that regular wood decking required about 1/8 inch of space between the deck boards. How about with Trex decking. Our deck was installed with the Trex boards butted up against each other and the result is that it holds rainwater and dirt and the deck needs to be swept after each rainfall or I start to get a green mold forming. I was thinking of taking my circular saw and cutting a kerf intermittintly between some of the boards to allow it to drain. What is your advice?

Well, you are right about the spacing. They really should have left a bit of a gap between each board. But cutting a few slots here and there is not going to significantly help your problem unless you have lots of puddling taking place. Mold and mildew can be kept under control by frequent cleaning. A power washing now and then would take care of it. If you don't have a power washer, a bit of laundry detergent or deck/siding wash and a stiff brooming, followed by a rinse with the hose should be enough to keep it sufficiently clean.

Your other option would be to complain to the company that installed it that way.

Removing every other board, ripping them down to 5 1/4" and routering the edges would not be an easy or fun solution either. But aside from removing and reinstalling the entire deck, I'm not sure what a perfect solution would be.

Trex, or any other composite decking HAS to be spaced!! The spacing between the sides of the boards is 1/4" minimum in the summer, when the boards are warm, and 3/8" in the winter, when the boards are cool. At the butt joints. leave a 1/8th gap.

Composites are exactly the opposite of wood. They grow in the heat (summer) and shrink when it's cool (winter). Wood reacts to moisture -- it grows when it's moist (winter) and shrinks when it's dry (summer).

Thanks for the information. I'll be talking to my installer, but he believes his installation is correct.

The Trex website has a FAQ where this question about gapping is answered.

http://www.trex.com/Universal/faq.asp#gapping

If the decking is Trex, there is no question that your installer is wrong.

The Trex installation guide specifies 1/4" width to width spacing when installation temps are above 40F, and 3/8" width to width spacing when installation temps are below 40F.

see: http://www.trex.com/litcenter/Trex_installation_guide.pdf

Yes the product is Trex, not any of the other brands of synthetic decking material. Was bought from a lumber yard.

I have the same problem.....the porches were built 5 years ago with no gap. Taking it apart is not a viable option. Was think of drilling holes intermittannly on the seams, but the circular saw sounds interesting. Did it work or does anyone else have an idea?

Everytime it rains, I get major puddles! Any help would be great.

Thanks in advance

Sykes

Drilling holes for drainage is one thing. Gapping the boards to allow for expansion and contraction is another.

Sykes, you REALLY need to pull the deck boards off and gap them so that they have room to "GROW" when the weather gets warm.