TIL my new deck boards need a 1/8 inch gap or they'll rot out in 2 years

I was getting ready to install some cedar decking last weekend and decided to double check the spacing. The hardware store guy said to butt them tight together, but I looked up the manufacturer specs online and they said 1/8 inch is required for drainage. Without that gap water gets trapped between boards and the rot sets in fast. Has anyone else run into this problem after following bad advice from a store employee?

2 comments

2 Comments

webb.xena22h ago

My neighbor built his deck in 2006 with zero gap and it's still standing, no rot, no issues. He used pressure treated instead of cedar though so maybe that matters more than people think. I've got a buddy who laid his cedar boards tight and they've been fine for 8 years in a covered porch situation. The whole "inside out rot" thing sounds dramatic to me, like water is gonna sit there forever when it's literally outside and exposed to air and sun most days. I'm not saying gaps hurt but I've seen enough tight decks last just fine that I'm not convinced it's a guaranteed death sentence.

josephb351d ago

Yeah the butt tight thing is a classic mistake. I did that on my first deck years ago and was pulling rotted boards within two years. You need that 1/8 gap minimum or the water sits between them like a sponge. Cedar especially needs to breathe or it'll rot from the inside out. Get yourself some 8d nails or a cheap circular saw blade spacer to set the gaps consistent as you go.