I need suggestions on how to fix my retaining wall.
Is there a quick and cheap way to fix it? Unfortunately, I don't have the money right now to spend on replacing everything.
You will notice that there is rot and a hole in the lumber:
You will see that above my retaining wall is our fence:
Best Answer
Although it looks to be functional at this point eventually the bottom tier will rot away causing the retaining wall to fail. You have a legitimate concern. There is no simple answer to this because the right answer is to rebuild the wall. I'm assuming here that the wall has compacted soil on the other side. Since the bottom tier is rotting, and if you're willing to invest some sweat equity in this project, one less expensive option might be to cut out the bottom landscape log with a wedge and sledge or axe. This will be labor intensive but not expensive. Remove one section of the log at a time, removing soil by hand and shoring each section up with pavers/landscaping blocks of the same height as the log. Work along the entire length until you have replaced the entire log with landscaping blocks.
You will mostly have vertical pressure on the bottom log from the weight of the retaining logs above it and whatever structural material is above the logs. The bottom log will not have a lot of lateral pressure from the soil behind it. The main thing you need to do is make sure that as you remove small sections (a foot or two at a time) that the pavers you put in its place fit securely and are on a solid base so as you transfer the load to the pavers there is no compression of the course of pavers. If you do that you'll be fine.
Any soil under that bottom log should be well compacted but you could put a layer of pea gravel under the pavers before you insert them. If you tap them in with a hammer be sure to hold a wooden block over the side of the paver as you tap it in so you don't crack the paver.
The blocks don't have to be flush with the logs above. It will appear to be a base for the wall.
My neighbor and I fixed his retaining wall along the steps to his basement years ago (when we were both in better shape and in our late 20s). We had it dug out by hand in a few hours, but it was mostly clay, and didn't require shoring up. If you've got a long length, or sandy soil that's going to keep filling in as you dig, it might not be a good option, but it's really not that much work.
Digging out a pit isn't as hard as something like trenching, where you're always bending over ... with digging out the retaining wall, you can get in the hole, so you're not constantly bending over.
There are also plenty of ditch-digging equipment that could easily get through a five-foot opening. If you really wanted equipment, measure how much space you have, and call your local tool rental shop; there's a whole class of 'mini-excavator' that might be able to get back there. If you needed to loosen the soil, you could use a tiller, but then excavate by hand.
I've recently purchased used railroad ties from home depot for my own landscaping needs. They were the cheapest by volume that I could find about, $15 for an 8"x10"x8' (nominal), and if you want something that's going to match the worn look of an existing railroad tie retaining wall, well that's as good as it gets.
Concrete blocks will be more expensive and probably will stand out. If you're not going to cement and rebar them in, I also find blocks harder to get set in so they look professional.
Best Answer
Although it looks to be functional at this point eventually the bottom tier will rot away causing the retaining wall to fail. You have a legitimate concern. There is no simple answer to this because the right answer is to rebuild the wall. I'm assuming here that the wall has compacted soil on the other side. Since the bottom tier is rotting, and if you're willing to invest some sweat equity in this project, one less expensive option might be to cut out the bottom landscape log with a wedge and sledge or axe. This will be labor intensive but not expensive. Remove one section of the log at a time, removing soil by hand and shoring each section up with pavers/landscaping blocks of the same height as the log. Work along the entire length until you have replaced the entire log with landscaping blocks.
You will mostly have vertical pressure on the bottom log from the weight of the retaining logs above it and whatever structural material is above the logs. The bottom log will not have a lot of lateral pressure from the soil behind it. The main thing you need to do is make sure that as you remove small sections (a foot or two at a time) that the pavers you put in its place fit securely and are on a solid base so as you transfer the load to the pavers there is no compression of the course of pavers. If you do that you'll be fine.
Any soil under that bottom log should be well compacted but you could put a layer of pea gravel under the pavers before you insert them. If you tap them in with a hammer be sure to hold a wooden block over the side of the paver as you tap it in so you don't crack the paver.
The blocks don't have to be flush with the logs above. It will appear to be a base for the wall.