Must you space outdoor wood decking?

Question

I was helping my father-in-law install the floor decking on his wooden patio recently, and everything i've ever heard about installing decking says that you must space out the planks as they need room to expand and contract. We were using pressure treated wood, and my fil insisted that we jam the planks flush with one another. we're about 1/4 of the way done...should we go back and space them or will it be just fine?

Thanks

Answer 1

DO NOT LISTEN TO THESE PEOPLE!!! keep them tight together. when the wood dries out it will shrink and create gaps. if you space it  the gaps will become so large you could loose a small child through them.  i have built more than my share of decks and walkways. keep em tight.

Answer 2

I'm going with Tom Silva on this one as well. You definitely need to space the boards about the thickness of a 16d nail. That will give you enough of a gap to account for expansion of the deck. If you don't allow for this, the boards could expand against one another and start to cup.

Answer 3

I agree with repobud. Pressure treated wood is wet if you install it tight then as it dries out you will get a nice gap. However if you space it as the wood dries out you may get a larger gap than you wanted.

Answer 4

You are right. Those boards really should be spaced.

Pressure treated wood will take up water and swell just like untreated wood.

Answer 5

The wood will expand and contract, and probably buckle. I used a large nail as a spacer and had no problems. Not spacing the boards will also allow water to puddle.

Answer 6

Either way ,esp if using 5/4  treated deck boards.

As mentioned the decking will contract more than expand & you may end up w/ a slight space anyhow.

Have spaced decking to allow sand to sift through & make sweeping easier.

Your call.

Best regards

Answer 7

Wood just like everything else expands.  You have to have room for it to do that plus you want the water to be able to run off.  

Answer 8

The pressure treated lumber will shrink a little so you should be okay. Anything other than pressure treated is spaced the width of a 16 penny nail.

Answer 9

Space them.

Tim Silva of This Old House uses spacers. If there was EVER a guy on the plante who knew what the h**l he was talking about it is Tom Silva.

Space the planks.

Eric

Answer 10

I would say YES!!!!! If you don't space the out the boards ( about a 1/4 inch ) then water will lay on the deck with no place to go & cause the boards to rot alot faster pressure treated or not. The spacing will also allow air to flow threw & dry faster. I learned this the hard way & my deck only lasted 4 yrs.

Answer 11

Depends on the condition of the lumber when you start the project. A lot of treated lumber is damp when you buy it. An easy way to tell is drive a nail though it. You'll see moisture ooze out on a wet board.

If the lumber is damp, keep the boards touching each other while you're laying them. One person said they will shrink when they dry out, and that is correct. You will then have gaps the correct size.

If the lumber is dry when you're installing it, you can use a spacer.