Fasteners for a plank deck

[Ernest T. Bass]

Hi all, I have a quick little question...

We will be installing a 2'' (1.5'') plank roof deck on our cabin soon. The rafters (logs) are spaced 4'.

What would you suggest for fasteners? I was wondering if common nails would start to loosen in time, and if we should go spiral or ribbed? Would 10d be about right?

Thanks for your input! The references I keep finding to nailing board decking is always for 3/4''..

[MountainDon]

is always for 3/4''..

3/4??  5/4" I could believe.


Common nails will loosen and self extract over time. Spiral or ribbed should hold much better.

Nails should penetrate a minimum of 1 1/2" into the joist, so the 10D would just meet that, if you were nailing into flat/square stock. However I'd go 12D at least if it was me. If you're nailing into round logs I'd go 16D just to make sure I had enough penetration.

Hot dipped galvanized.


Personally I prefer deck screws for something like that.   2  1/2", or longer on round stock. 

[Ernest T. Bass]

I'm open to screws if they would be more adequate, but expense and time are also a consideration...

The logs are flat-sided, so no problem w/ good contact.

Why galv.? VB and insulation will go over the deck, so there shouldn't be any moisture problems..

Usually when I read about board decking it is in reference to 1'' nominal (3/4'') t&g stock.

[MountainDon]

re: galvanized     I was thinking of a deck as in a deck exposed to the weather, not as in a deck that would be insulated, etc. Just the way I interpreted your statement.  If it's not going to get wet you can skip on the galvanized.


If the joist logs are 4 ft. apart it seems to me that the 1" (3/4) is not thick enough.  But then you also mentioned using 2" (1.5") planks... So I guess you've got me confused.      Are those 2x's T&G?


When you stated "roof deck", I envisioned a roof mounted deck you'd be walking on, picnicking on, enjoying the sunset from, etc.      This kind of decking is available in 5/4.

If this is a structural part of the roof you do not want to use screws. If it's covered over then standard common nails should suffice. Once again I was thinking deck as in something you entertain on. On those I have seen common nails slowly work their way up out of the wood.

[PEG688]

I stayed out of this one to see if someone would flesh out what we are doing here.

Now re-reading the posts , I think we are talking about 2x6 T&G car decking laid on flat topped log rafters. As roof sheathing.

If thats right I'd recommend 16d galv box nails. They won't "back out" and poke a hole in the roofing.

Your logs will allow for that without the points coming thru the ceiling side of the rafter I'd think , if not I'd say your log rafters are to small except for a very small building / short span / run.   

[Ernest T. Bass]

You're correct, except for the t&g part. These are just rough-cut 2x6's, sawn to dressed dimensions.

I guess I have to ask again... Why the galv?

Yes, this is sheathing, not a porch type deck.. Guess I should have clarified.

The only reason I mentioned 3/4'' t&g is because it is the only board sheathing I've ever read about, and my situation is different. Sorry for the confusion.

I know they won't back out from foot traffic, but doesn't the roof flex a bit from wind, etc.? Wouldn't this potentially loosen smooth shank nails in time?

[PEG688]

\

I guess I have to ask again... Why the galv?

Third line of my last post.

If thats right I'd recommend 16d galv box nails. They won't "back out" and poke a hole in the roofing.


You need a nail  that will hold well , sinkers would back out , you'll have a lot of wood movement as that roof drys out , the nails really need to hold well. Drive in 5 ea. Galv. 16d and 5ea.   16 d sinkers , then pull them out and you'll know "why" the galv. nails .

You don't want the nails working up and out thru the roofing.  Means a leak! 

[NM_Shooter]

A quick question to add...

When I nail things down that I don't want to work loose, I sometimes put a bit of an angle on the nail, and then angle the next nail differently. 

My thought is that any stress on the board that is not a shear load is better handled if the fasteners are not all parallel. 

Wives tale?

-f-

[Ernest T. Bass]

I usually do that too; not really sure if it makes a difference.

So, the galv. coating bites the wood better, I assume.. What about spiral? Unnecessary?

[PEG688]

 I'd say yes, the opposing angled nails would help some the holding better.


The hardest nails to pull are galv-ie's , followed by the old bright commons which today are not that commonly available. The spirals and ring shanks don't hold as well IMO.

Is this a case of "I got a box of spiral nails for free , can I use them?" If so ya I'd go for it , if I had to buy the nails I'd get  the Galv-ies.


No 1 1/2" rough sawn stock which "generally" nets out thicker , about 1 3/4" , that would depend  who milled it , BUT IF it nets out at 1  1/2" or better I'd definitely use a 16 d fastener.   

[Ernest T. Bass]

They're pretty much 1 1/2'', spot on.. Convenient, 'cuz you can use them w/ regular joist hangers and stuff. Plus, they're a bit cheaper as well.

We got 30 lbs of 16d galv. ring shank nails on amazon for $74 shipped. Thought it was a good deal, considering 30 pounds of regular 16d galv. nails are over $80 at the local building supply..

Thanks for the help! Gotta get that roof on before the snow hits...