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Discussion Starter · #1 ·
I had a two-tiered stone retaining wall installed professionally to replace a rotten timber wall, which had a deck secured to it / resting on it (yes... I know!!!!!).

I had the lower wall built with a recess to build a deck into (see pictures below). The area to build in is 17' wide by 15' deep (from the house). The recess is 4' deep. I have experience building a beam on post deck that had no major complications / restrictions (plenty of room to work).

I have two issues:

1) I'm nervous about digging footings too close to the retaining walls and compromising the integrity of the wall. The wall had proper base material installed and compacted. I want to get footings into the "cutout" of the lower wall (see pictures). How far away from the walls can/should I put a footing? I was hoping to get the deck as close to the walls as possible.

2) I only have about 8-9" from dirt to the bottom of the joists. I looked around online for information on a flush beam but am not able to find very much. Are there such things as "flush beam joist hangers" or some way I can through-bolt the hardware that would be more secure than nails? I'm worried I would not be able to do any overhang with a flush beam (which I need to do if I can't get the footings too close to the wall). Are there any other things I need to take into account when using a flush beam?

Hope this makes sense, looking forward to any advice. Thank you!
 

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retired framer
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Yes after the 1st 12" it is all clay (at least as far as I've ever dug!). Thank you so much for the help! I've been losing sleep over this for a while!
Cut the bottom few inches off a 5 gallon pail dig down into the clay and install the pail and back fill around it. Finish digging the hole thru the pail.



BTW two hangers would be installed upside down so the outside rim is supported from the ends of the beams.
 

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Discussion Starter · #10 ·
Cut the bottom few inches off a 5 gallon pail dig down into the clay and install the pail and back fill around it. Finish digging the hole thru the pail.



BTW two hangers would be installed upside down so the outside rim is supported from the ends of the beams.

Both of those things make total sense! :smile:


I wish I would have posted here months ago. Thank you again for your help and quick response!
 

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Hammered Thumb
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I wouldn't be worried so much about augering a post footing next to the wall. It's when you are on top of the grade that the wall is holding back is the concern.

I would remove the concrete stoop. It looks 5' wide to match the slider, that ledger there is maybe 3" tall? Too big an area to use 2x4 joists. And capillary action of water sitting on top the stoop back under the ledger board, and movement of the stoop. Also, it looks like you used GRK screws for the ledger. Minimum 1/2" lag screws.

You should follow DCA-6 Prescriptive Guide for Decks, whether a permit is required or not. It is pretty good as a step-by-step how-to. It will tell you the size of your beams and post spacing for a simple layout, which you do not have so far.

With this plan you need 2x10 joists. When you frame joists into both sides of a beam, you have to size the beam to consider the span on either side of the beam. An inspector may even want the joists offset. Also, you will have 4 girder beams, I imagine most DIYers are unable to size those, and 6 'standard' beams.

P.S. if you haven't noticed it yet I imagine it is an echo chamber back there, especially once you are sitting on the deck within the retaining wall notch. Some plantings can help mitigate that.
 

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Discussion Starter · #12 ·
I would remove the concrete stoop. It looks 5' wide to match the slider, that ledger there is maybe 3" tall? Too big an area to use 2x4 joists. And capillary action of water sitting on top the stoop back under the ledger board, and movement of the stoop. Also, it looks like you used GRK screws for the ledger. Minimum 1/2" lag screws.


...


P.S. if you haven't noticed it yet I imagine it is an echo chamber back there, especially once you are sitting on the deck within the retaining wall notch. Some plantings can help mitigate that.

I was thinking about removing the stoop, but I think I "monkey see monkey did" with what the previous ledger did in that location. I know it's not up to snuff over the stoop but I guess I was thinking the previous deck lasted 30 years and still felt solid with 2x4 joists over the stoop. Good point about water sitting there I had not thought of that. More excuses, but the second story does overhang the stoop and that area stays relatively free of rain and snow. But now I just feel like I'm making excuses :)

I followed the GRK structural screw tech bulletin for ledger boards, so I thought I was ok to use them instead of lags:
https://www.grkfasteners.com/getatt...4aad-8456-537e06f76847/LedgerBulletinvs-3_new

Did I just fall for some marketing wank?

As for the echo chamber, its not bad back there. Bushes in the first wall and giant evergreens up top do a pretty good job of dampening everything. But I did want be raised up so I didn't feel like I was sitting in a prison. Why I'm going for a deck over a patio in the first place.
 

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Hammered Thumb
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Simpson has their documents showing equivalency with their fasteners, if GRK does too all is good.

My main point is you can have just one beam along the retaining wall, then a simple span of 2x10 joists (prob 12" o.c. though) back to the ledger. But a continuous ledger. Suggesting KISS.
 

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Discussion Starter · #14 ·
Simpson has their documents showing equivalency with their fasteners, if GRK does too all is good.

My main point is you can have just one beam along the retaining wall, then a simple span of 2x10 joists (prob 12" o.c. though) back to the ledger. But a continuous ledger. Suggesting KISS.



KISS is good. Now I have some decisions to make :)
 
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