I need to replace a crumbling stone retaining wall in the back of my house. The main wall is about three feet high with six feet of level ground behind it then a short (12-18″) retaining wall. Behind that is a concrete patio.
What I am considering doing is building essentially a short fence, with PT 6×6’s sunk in postholes, with PT 2×6’s or similar screwed to the backside of the posts. Then I would backfill with gravel, provide for drainage, etc. etc. etc.
Before I get to the questions portion of the program, let me say that I understand that the local code enforcement authorities will have final say, and that I will of course get all necessary permits. I’m here just looking for some opinions.
So, the question. I would like to sink the posts in compacted gravel instead of concrete for the sake of longevity. Looking down the road, we have talked about building a wooden deck over the concrete patio, which is cracked and settled completely out of level. What would I need to do in order to be able to use these 6×6 retaining wall posts as part of my future deck structure? Would I be able to pour a concrete pad at the bottom of the hole, then install the post surrounded with gravel?
Thanks!
Bart
Replies
It all seems feasible to me. There has been some debate here over the years as to the best way to set PT posts for longevity, and your method was discussed. I guess I would think you'd get 25 good years out of it; is that enough?
I don't know how wild I'd be about the idea of using the fence system of 2x material for your retaining wall, at least for looks, but I don't have to look at it, you do. If you think that it looks okay, great! Maybe it would. But if you plan to do it this way, maybe leave the posts sticking up to the height you would need for your deck in the event you would add that in later.
My preferred method is to use 6x6's laid lengthwise and stacked up, kind of overlapping each other like stairsteps as they get higher. This is all pinned together with rebar and large spikes, and tied to the ground and house with more pins and timbers.
Where are you located? Some consideration for drainage and moisture, freeze/thaw may affect your decision.
Anyway, I didn't see anything here as a red-flag nono.
Edited 5/13/2003 12:11:26 PM ET by Mad Dog
Thanks Mad Dog. I'm in Middle Tennessee, so freeze-thaw isn't really much of a problem. I thought about the stack-up method, but doesn't that require deadmen back into the slope? I would rather avoid that much excavation if I can. Also, it seems like it would be harder to anchor the deck to the wall that way.
So you think pouring a concrete pad at the bottom of the hole would work? Kind of like a post placed on top of a concrete pier, except underground.
Bart
Yes, it does require timbers laid back into the slope. But they don't need to be too long to get the job done. if you are not going too high and the hill side is fairly stable you can get away with 2 footers.
Brian P.It's my job!