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SirMaxPowers t1_iugwo2k wrote

Reply to comment by OrangeYouGlad100 in What is the max joist span for a deck with deck blocks? by OrangeYouGlad100

That's too much over kill on the pierpads/ deck blocks. For 16' you should have 3 pads/ blocks on each doubled up 26, 2 towards the end and 1 center. I would add a double 26 beam in the middle for added support/ to help bounce or defection. So imagine the beams going the 16' length, two where you have them at the top and bottom, one in the middle. So 3 -16' " beams" or double joist, and 9 pads total for a rock solid foundation.

Also if you add butyl tape/ window flashing that comes in rolls, on top of the joists where the decking meets ( on top of the 2*6 where you screw the decking) your joists will last a whole lot longer.

That 3 beam setup would be strong enough for most environments/ weight.

Here in WA if the deck isn't over 30" off the ground you don't need railing.

Also they sell concrete blocks/ pierpads with an adjustable 4*4 metal bracket so if you mess up a cut or the ground settles, you can use a wrench to adjust it up and down. Good luck..

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OrangeYouGlad100 OP t1_iui3h4e wrote

Thanks for the suggestions! Unfortunately, I already bought like 20 deck blocks that have a space for a single 2x and therefore can't fit a double beam (this kind https://www.lowes.com/pd/Common-7-in-x-11-in-x-11-in-Actual-7-125-in-x-10-375-in-x-10-375-in-Concrete-Deck-Block/50113084 ). I suppose I could return them all.

Alternatively, could it make sense to use 3 beams like you suggested, but put the blocks under joists instead of beams like in my picture? I got that idea from these plans:
https://gardenplansfree.com/furniture/deck-plans-free/

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SirMaxPowers t1_iuiece6 wrote

What's the load/ weight your putting on this? Usually the load is supported by beams running 90 degrees to the joists.. I can't speak to this plan, I've never built one like this but it doesn't mean it's wrong..

Unless your installing on concrete you'll want to make sure all 20 blocks are level and even with each other. That can be a pain but depending on skill and terrain. But if you're going for a low profile look than this might be better than buying and burying adjustable pierpads. Good luck!

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OrangeYouGlad100 OP t1_iuigsa7 wrote

Thanks. Aside from the weight of the deck itself, it will only need to support a few deck chairs and a few adults. And yes, it will be low profile. The joists will be just an inch off the ground and the surface of the deck around 8 inches high.

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SirMaxPowers t1_iuihmkv wrote

Gotcha. Make sure you use treated lumber, not much ventilation under there. Good luck.

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