I’ll be starting a deck next week, and thought that I might double every fourth joist. That way when I stagger my deckboard joists joints on 4-ft intervals I’ll have better bearing and an easier time installing deck boards.
It’ll cost me an extra $50, but I think it will be worth it for the time and hassle factors when decking.
Anyone else do this.
P.S. I ordered SS hangers and nails from McFeelys to use as part of my “better built” customer promotion, if you will. Would it be worth it to order their ProMax SS deck screws also, or will the Lowes/HD SS deck screws suffice. I’d like to minimize pre-drilling as much as possible for speed reasons. All PT S pine lumber.
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I don't like sistering joists on an outside deck. The small space between the new joist and old always catches dirt and moisture and increases rot.
Hopefully a Mr. Razzman will come along and tell you that if you'd filled out your profile we might know whether you live in a rainforest or a dessert.
I'm thankful for the loyal opposition! It's hard to learn much from those who simply agree with you.
i dont think its such a bad idea to beef it up,hell thats my motto beef it up baby!as far as rot i dont think you need to worry about it,because then you would have to worry about the main beam rotting as well wich it wont,any time i build a deck my understructure is all pressure treated so...
You can sister a one foot piece as a nailer as you go along. I think doubling the whole length might be overkill
Rather than just double them, you should space them with 2x blocks. This allows you to gap the ends of the deckboards for drainage and allow for even more room at the ends for nailing. This is detailed in the Pros Deck book (taunton press).
Hi Mike, spacing the joists helps the rot situation. Use rubber or plastic... then it doesn't hold moisture. (we use truck mud flaps...cut into little strips).
There's flashings available now to prevent the joists from rotting on the top as well.
Seal the end grain with stain to prevent rot... sounds like you care about what you are doing. Nice to see Mike.
L
GardenStructure.com~Build for the Art of it!
Use a spacer between the joists -- 1/2" or better.
I agree that the best way to avoid rot on exterior decks is to double up joist with a 1/2 or better spacer where floor boards are to meet., However it is also important to allow a small air space between the floor board ends so moister does not sit and allow air to dry the ends.
A reminder that when building a deck with the new PT, it does not mix well with Galvanized products.
George
Doubling is overkill, but adding a 2x4 sistered along the top edge would help keep your butt-joint screws further from the ends, which is nice. I think if I were doing that I'd simply add a short chunk of 2x4 glued and screwed to the joist right where the butt is, rather than along the entire length. The idea about using rubber strips to space things is excellent, as is the idea about flashing the tops of the joists. Grace makes a narrow roll of Vycor just for that purpose.
When you lay out your joist positions, be sure to space the second joist 10-12" from the first, and then continue your 16" (24"?) layout from there. That will allow you to easily use normal lumber lengths for the starter piece in each course. Does this make any sense? I once had a deck a frame built by someone else, all on 16" centers, and it means a LOT of waste. Photo attached of a frame I laid out... first joist in on a 10" layout, rest on 16"