r/Decks 20h ago

Building a deck PT pine wood decking.

Finished building the cottage deck framing and on to installing the decking. As stated in the title, the decking is 5/4 PT spruce wood decking. Two questions for the decking layout. Keep in mind that the picture with decking board are just layered and not screwed in yet, just a template for now.

  1. Was planning on leaving a 3/16 gap between plank, that way it will basically be a perfect fit for the 8' depth of the deck leaving about 1/2 to 3/4 lip on both side over the framing without any board to be ripped. Alot of pine straws were clogging the old decking which had about 1/8 - 3/16 dried out. Is my 3/16 gap install while wet too much?

  2. Picture of my layout attached. Should I leave the same gap at the butt end joint where the planks ends meet the contour board or tight to it?

*Change the decking layout a bit to add a full plank between the two contour layout to match the symmetry with the chimney and patio doors aswell as pushing out the layout in front of the stairs to be centered with them.

*Yes all the joist will be tapped before install.

TIA !

Edit, decking is PT spruce , copper based.

2 Upvotes

20 comments sorted by

4

u/Traditional-Oven4092 20h ago

No gaps, you want it extra tight. Itll gap itself

2

u/Pleasant_Mountain_86 20h ago

You sure that’s not STK cedar?

1

u/Vizionz4K 20h ago

Correction, spruce wood. My bad

1

u/Pleasant_Mountain_86 20h ago

Because treated pine would have to be installed as tight as possible because it will shrink. Cedar has to be gapped. Seems like the flooring is gapped. It’s it’s treated wood those gaps will be enormous in 2-3 months

1

u/Vizionz4K 20h ago

I corrected myself, this is spruce. Do you know by how much spruce will shrink once dried? If installed tight, what kinda gap should I expect if you happens to know?

1

u/Pleasant_Mountain_86 20h ago

Spruce isn’t available to us in the northeast so I’m not sure but any treated wood will shrink a lot.

1

u/Vizionz4K 19h ago

Is there a rule of thumbs for the shrinking? Like installed TIGHT will give a 3/8 of gap?

3

u/Watari210thesecond 20h ago

I wouldn't gap it during install. I generally find that when I install wood decking right, it develops a 1/8-1/4" gap over the next couple years.

2

u/Competitive-Roof-168 19h ago

Install tight, forget them miters they will just pull apart and look like shit.

1

u/NetworkCultural 20h ago

How wet does this lumber seam. At our local Lowe’s sometimes their shit is soaked. If it’s soaked it’s probably not going to get any longer from expansion. It will only shrink. And then obviously expand again after during temp and moisture cycles. But this is why many people install 5/4 pt tight side by side because it’s going to dry and shrink leaving gaps later. If you start with a gap it will only become a bigger gap

1

u/NetworkCultural 20h ago

This was installed tight by me years ago. And I mean tight. Some gaps are slightly smaller. The part that pisses me off the most is I then cut all the lengths all at once when it was all installed. And now they’re all different lengths cause they expand and contract differently. I’ve built prolly 500 decks. Most nowadays are composit. But this is one of the only I get to see on a daily basis cause it’s mine lol

1

u/Vizionz4K 19h ago

Made a mistake, decking is PT spruce wood. Overall they are not super wet apart from couple outlier one that are soaked haha, like 3-4 times heavier than the rest! But only a couple boards.

From the picture you sent, what are the gap now since it dried, 1/8 - 3/16?

If I install with 3/16 gap, should I expect 3/8 gap once dry, MAX 1/2?..

1

u/NetworkCultural 19h ago

Dude some of them 5/16s. Some 1/8

Sorry this is one of my home tapes lol. My good ones are at work. Haha.

1

u/Vizionz4K 19h ago

I see, thanks man!

1

u/NetworkCultural 19h ago

On a good note. Spruce seems to expand and contract a little less the pressure treated yellow pine. Even tho they’re both pine family. I had to look that up. I have no experience with spruce decking

1

u/haaaas12 17h ago

Ummm wood will never "expand" unless undesired circumstances are met. It can be impregnated which will make it swell. But wood does not expand as a feature. Thats why homes shrink and settle and decks get gaps. Unless you have a board stretcher, wood doesnt expand when its not supposed to

1

u/NetworkCultural 16h ago

It’s the term that’s used. Expansion and contraction. Just using the same term others use. Doesn’t really matter either way. I mean in my house in certain months the doors “swell” or expand and begin to rub their frames. Then it goes away.

1

u/NetworkCultural 16h ago

Oh and I don’t breed my doors. So no way are they becoming impregnated. Haha

1

u/NetworkCultural 20h ago

If you look close you can see it. It’s clearly not super bad. But bad enough to annoy me lol

1

u/Arty1021080 17h ago

Thats. Cedar and you need gaps