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I am extending my deck and plan to make it a freestanding deck (just to avoid attaching to the current one but it will be close on top).

I plan to have a row of 4 posts on the lower level (left). Each post has 4x4 on top of pier block with metal bracket (same as existing deck):

http://www.homedepot.com/p/Concrete-Pier-Block-with-Metal-Bracket-8053112/202820094

Then on the upper slope, I am planning to use 2x8 and put on top of this pier posts:

http://www.homedepot.com/p/10-in-x-10-in-x-8-in-Concrete-Deck-Block-012023A/205613606

enter image description here

Do you think this is OK?

  • Depends how you plan to use those blocks. Are you planning to bury them 30" deep? decks.com/how-to/573/… – Tyson May 13 '16 at 13:18
  • I won't be burying them completely but leave like 1/3 above the ground. – HP. May 13 '16 at 23:22
  • Did you read the article I linked? That type block should be sunk to be below the frostline. @benWelborn answer is awesome. – Tyson May 14 '16 at 0:28
  • Yes I read all the articles in that link. We are in Seattle so no frost line. But I am planning to dig 1 foot deep, fill with 5/8" minus like 3-4 inches, then put the blocks on top. – HP. May 14 '16 at 18:04
  • Depending which map you look at the frostline in Seattle is either 18" or 24" – Tyson May 14 '16 at 18:09
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Those pier blocks or deck blocks are a waste of money. It's not going to be as difficult to dig a few holes and install some real posts now as it will be after the deck is complete and has sunken (unevenly). They might be okay for a light duty shed or dog house, but nothing significant, like a deck.

Edit based on comment:

enter image description here

  • Sure. But from architecture stand point, do you think it's OK to have 1 side using 4x4 post while the other side using the 4x8 as the beam directly on the pier footing? – HP. May 13 '16 at 23:23
  • @HP 4x8 or 2x8? (or two 2x8s together?); the concrete blocks are made for 2x8... or various sizes. Supposing that you had solid footing, it would be ok. Editing answer with pictures. – Ben Welborn May 14 '16 at 3:04
  • The block is for 4x8 like lowes.com/… because it's the beam right? I mean I can't just use 2x8 for beam, no? I guess my main concern is if it's OK architecturally to have 4x4 posts on one side and just beam directly on blocks on the other side. – HP. May 14 '16 at 18:01
  • @HP Whether you set the beam on a block or a post doesn't make the difference. Without getting distracted by technical exceptions, you could use a 2x8 if you have it thouroghly supported. If you use a 4x8 beam, then it should be able to hold more weight, and/or require less support. But since the support will be blocks placed on the ground, I would probably use 4x8 plus extra blocks for support (distribute the weight). Sinking blocks/support is the primary concern. – Ben Welborn May 16 '16 at 12:32

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