deck board spacing: KD19 5/4x6 southern pine

[Glacier]

Hi, I'm building my first deck. I have a couple of questions regarding decking board spacing. I have almost completed the substructure, where

2x8 joists are spaced on 16" centers and I'm going to use 5/4x6 decking boards perpendicular to the joists. Actually I have purchased 5/4 x 6 presure treated decking boards, the stamp says KD19 southern yellow pine. They've been sitting in my carport (you know, a garage with only a roof, no surrounding walls) for about 3 weeks.

The first question is about the spacing between decking boards, I've seen conflicting posts on google on this matter, some recommend using

8d-10d nails as spacer, others insist butt the boards tightly for PT. I figure it has a lot to do with how dry (or wet for that matter) the wood is. So is KD19 considered to be dry? The boards has been stacked tightly in my carport for 3 weeks, how will this affect the dryness of them? I measured a couple of the boards and they are between 5 9/16" and 5 5/8". Will they eventually become 5 1/2" when they are completely dry? Also, a question for those who has used similar woods, roughly how long after installation will the board dry out to produce the final spacing (a week, a month, or 6 months)?

To speak of spacing, what do people deal with the first row of board that go against the house, I'm confused because I've reading different opinions - some say butt against the house, other say leave a 1/4" to

1/2" gap to allow drainage. Please advice.

A final question, what are the pros and cons of starting laying the decking from the house side versus starting from the other side and working towards the house? Which one is more practical? I've read in a book where it is suggested that working from the outmost side towards the house to laying deck boards is a better way because a narrow row of decking will be less apparent against the house.

Thanks in advance for your help. BTW, I'm in Massachussetts if that will have an effect on the answers to my question.

- glacier

[Rob Spear]

Put them as close together as you can as you will end up with a 3/16 gap by doing this............note: i have never seen dry treated lumber.......the word of the wise.

Hope this helps you as the first deck i build i left an space and was sorry for doing so.........just completed my 3rd deck and very happy with the spacing on the last 2.

[Unisaw A100]

Ditto what the others said. I pulled all my decking together with pipe clamps (built 3 years ago) and right now I'm looking at gaps that are 1/8" to 3/16".

UA100

[Bill]

I've built a few decks in the Maryland area and always butted the (5/4 x 6) decking boards tightly. Within a year, there was an 1/8" to 1/4" gap between boards. I've seen decks where the boards were spaced and later had as much as 1/2" gap. I always started at the house and worked outward. You need to measure to the outside of the deck every few boards and allow a little gap as necessary to keep the boards parallel to the outside edge. I've cut as much as half of a board at the outer edge and it really isn't noticeable if there is railing. If you won't have railing, I'd consider working from the outer edge in.

HTH Bill

[Robert L. Witte]

I build decks as part of my remodeling business. I agree with Bill. Get those boards as close as you can and you will be amazed how open the parallel joints will be after a season. I use pry bars, other short bars and my Gorilla bar to push the boards into place.

One tip here, look around Google or get a woodworking book to see how to place the boards to prevent cupping. And remember no matter how you try you will never get the boards straight, so pop a reference line equidistant from the area you are working up to like your house, and make sure you maintain the same distance. Otherwise that last board could look like a giant wedge.

Make sure you cut off the splits on the end to square things up. I usually make the joist/subframing layout fall short by about one half inch so I can cut a quarter of an inch or so off each end of the boards to square them up.

Goog luck!

Robert

[Glacier]

Thanks to Rob, Bill, Robert, and UA100 for sharing your experience, much appreciated.

I'm going to butt the boards tightly to allow for the shrinkage of PT and I'll be laying the boards starting from the house side towards the beam because I'll have to build railings (deck is 4' high).

As for my second deck spacing related question, whether the first row of board should be placed tightly against the house or, there should be a spacing to allow rain water to drain - could someone shed some light? After the shrinkage of the boards, what will be considered a proper spacing between the first row of board and the house? Or there doesn't have to be gap at all? BTW, I used Z flashing to cover the top of the ledger, also roofing felt were placed between the ledger and the house.

Thanks,

- glacier

[Pat Barber]

[mike]

Butt them as tight as you can. Leave gap at the house siding. Start at either end, makes no difference.Rent or borrow a bowrench, makes pulling up boards a snap. I usually pull three or four boards up at a time then nail. Make sure you are using correct fasteners for todays new treated lumber. Stainless steel or double dipped galvanized is generally reccomended.Apply a sealer such as thompsons as soon as you can after completion of deck.

mike

[mike]

Butt them as tight as you can. Leave gap at the house siding. Start at either end, makes no difference.Rent or borrow a bowrench, makes pulling up boards a snap. I usually pull three or four boards up at a time then nail. Make sure you are using correct fasteners for todays new treated lumber. Stainless steel or double dipped galvanized is generally reccomended.Apply a sealer such as thompsons as soon as you can after completion of deck.

mike

[Dave Hinz]

I used a synthetic decking for mine, and the spacing is just shy of 1/2 inch. I have to agree that wide spacing isn't a bad thing, by any means. Like Pat says, the random crap has a chance to fall through, yet the gap isn't wide enough to catch toes, heels, or chair legs.

Shrinkage with the BORG's synthetic decking has been zero, FWIW.

Dave Hinz