Retaining Wall

[Chad_E]

Wife and I are wrapping up a new home build that we hope/planned as our “forever home”. The house sits on a bit of a slope and approximately 3’ of select fill was brought in for the house pad. Option A would have been to simply feather out dirt way from the house to create a soft slope. However, I didn’t like this option for four reasons. (1) That would have required me to bring in more dirt when in fact I already need dirt at the back end of my shop. Moving this dirt to the back saved me import. (2) Our last house had a similar if not slightly bigger drop off that was not fun (borderline unsafe) to mow and never mowed cleanly. (3) I like the clean look of a sharp drop off elevation change. (4) I'd like to try and save one of the trees that is close to the carport. So retaining wall here we come.



I explored the idea of just having this done in concrete. However, that would have been a costly endeavor and my wife didn’t like the idea of a plan ‘ol concrete wall, visually speaking. She would have wanted to put some sort of façade on it. Thus making it even more expensive. Having done a small wall back in 2010 at a house in San Antonio, I decided to do it myself and save some money (not time or energy!).

First step was to move away the extra fill material. I used the family tractor w/FIL to do just that. I rough cut the fill slope with the bucket.









Our landscaper had sent me a picture of a project that he had seen with some block he thought would match our house’s stone. After a bit of research I was able to find the Keystone product. Turns out it was a limited run product that was made specifically for the referenced project and they had limited quantities left. So they made me a “deal” on the nearly 8 pallets they had left.

[Matt_C]

Retaining wall was a win. Based on my house and foundation issues.

[Chad_E]

This weekend the real work began. With some figuring on the fly I started digging the trench for the first course of stone. The trench needs to be roughly 12” deeper than the finished grade at the face of the wall. 6” for a layer of base and to bury the first course of stone (6” deep/thick blocks) below final grade. It also should be approximately 24” wide. The block is 12” wide and you should have approximately 6” of base on either side of the in place block. After running string lines, confirming the final planned top of wall and verifying level grade the entire route, I started digging with a mini-excavator I borrowed. I was NOT a graceful operator, especially at first! But after some time I began to manage. By the end of the day and a bit of hand work I had the trench dug and subgrade compacted.











Sunday morning I used the tractor again to clean up the mess I made with the mini-x. Moved the trench spoils to the back of the shop and checked level on all the string lines again. Then I began bringing in the limestone base material, spreading and hand compacting in 3” or less lifts. I am trying to get the limestone within about ¼” of level. Then I checked, rechecked and checked again as I began placing the first couple of stones. This first course sets the table for the entire wall so I wanted to be extra careful and take into account all the variables. By lunch we had 3 stones set.

I’m using left over sand the stone mason left behind to do final adjustments to each stone as they are placed and leveled. The afternoon saw progress speed up while I slowed down. Being a desk jockey did not help. I hung up the gloves at 5 yesterday having gotten about 1/3 of the first course set. Once the entire first course is set, visual progress should speed up.



I’ll continue to update this moving forward. I fully expect this to take a few weekends to complete. Given that we will begin moving stuff into the house soon I wonder how efficient I'll be... I have a feeling the wife will want my energy spent getting stuff moved.

[Pedernal]

Looks like that color will match perfectly with your stone. In your search how much does it normally run for a pallet of the blocks and how much wall could one expect to build with the 1 pallet...

[Hogmauler]

Looks like you have it figured out! I was going to suggest building gabions.

[kae006]

Looking awesome so far, how are you planning to do the wall around that pipe in your last photo?

[Chad_E]

Looks like that color will match perfectly with your stone. In your search how much does it normally run for a pallet of the blocks and how much wall could one expect to build with the 1 pallet...

30 square feet (face ft - face of wall) per pallet. Price seems to vary greatly
by product and by quantity so I'm not sure I can answer your question accurately. I saw one place online that was selling the stone I'm using for $8.33/face ft and one for 10.88/ face ft which is $250/pallet and $326/pallet, respectively. I paid basically $80/pallet.

Looking awesome so far, how are you planning to do the wall around that pipe in your last photo?

Another stone will be just on the other side. Then I will bridge over either side with the largest stone in the 3-piece mix. I'll also be adding in sack concrete in this location. That is my gravity sewer line from the house going to my septic tank. I should have instructed my installer to put it a bit deeper. I had plenty of elevation change but didn't mention it. The results is we will have a larger flower bed area in this corner. But no big deal. I plan on building a raised cedar planter box that the wife wants to grow an herb garden in.

[Chad_E]

Just heard back from the sales rep that I bought from and he said normal price for the product I got is $290 (including pallet deposit).

[Dusty Britches]

This will be cool to follow. I'd like to do something similar.

[Chad_E]

Took off of work this past Friday to run a few errands and pick up some more supplies for the wall. Buddy of mine was nice enough to let me borrow his dump trailer so I picked up the gravel that goes behind the wall.

Friday I was able to get the limestone base in for the next third of the wall and get the bottom course installed and leveled.






Saturday was my oldest's birthday so I was only able to work till about 11 then between errands and someone that came by to see the house, I didn't get much done on the wall. I was able to complete the base and bottom course on the final stretch of the wall. This took a bit of figuring as you went because I had to stair step the wall's base up as the natural ground elevation rose to meet the back porch.


Sunday was a full day! Finally starting to see the wall come to life. The process goes: add a layer of stone, backfill with gravel, tamp and repeat. Here is a picture of the setup.


Approximately 7,250 lbs of hand placed stone plus about 1 cubic yard of gravel and this is what we ended with on Sunday. Just about halfway with the wall. Luckily, my wife chipped in and would tamp the gravel as I placed it which sped the process up and gave me a bit of a break between placing stones. The top layer of stone is glued down with a construction adhesive.




The plan is to put a staircase in the corner where we stopped. That will take some figuring. The plan is to now start from the other end of the wall and work our way near the same stopping point on Sunday. Then work on the staircase.


It was exciting to see the wall come to life. Hopefully another full weekend will get us close to finished. The landscaper and his dirt guy are scheduled in a little over a week. I'll need to have all the heavy lifting done by then. I won't be able to run the tractor in this area for a while after they move in. I can't imagine doing this work without the benefit of the tractor. To put it in perspective, our tractor is a 70 hp w/FIL. I have to remove the top layer of stone from the pallet because the tractor can't lift it when it is full. It's too heavy! Each pallet weights roughly 2,900 lbs.

[Mike Fangman]

Looks awesome, you're doin a great job, my back hurts just looking at the pics.

[TxAgHntr]

Man that is looking great!

Question and it is an ignorant one and maybe I missed it. Do you need to some how "tie" the wall back to the earth it is holding back...to keep it from falling forward over time...?

[meltingfeather]

Looks great-- nice work!

[Chad_E]

Man that is looking great!

Question and it is an ignorant one and maybe I missed it. Do you need to some how "tie" the wall back to the earth it is holding back...to keep it from falling forward over time...?

If the wall were taller or closer to bearing the load of the porches or carport, yes. At its tallest, the wall is only going to be retaining ~24". The load the wall supports radiates upwards at a 45 degree angle from its base. Therefore, it is supporting the dirt set 24-30" back behind the wall. The porches & carport are 5-6' or more back from the wall depending on where along the wall you measure.

The design of this particular wall includes ~1" lip on the back of each block which locks it to the block below it. There is at least one block below ground level for the length of the wall to keep the wall from "sliding" forward and to be the anchor for the stones above.

I'll say this. If the wall would have been 4' tall or carried a larger dead load (been closer to the porches), I certainly would have had at least one, if not two layers of geogrid tied back into the soil behind it to help support the load.

[TxAgHntr]

If the wall were taller or closer to bearing the load of the porches or carport, yes. At its tallest, the wall is only going to be retaining ~24". The load the wall supports radiates upwards at a 45 degree angle from its base. Therefore, it is supporting the dirt set 24-30" back behind the wall. The porches & carport are 5-6' or more back from the wall depending on where along the wall you measure.

The design of this particular wall includes ~1" lip on the back of each block which locks it to the block below it. There is at least one block below ground level for the length of the wall to keep the wall from "sliding" forward and to be the anchor for the stones above.

I'll say this. If the wall would have been 4' tall or carried a larger dead load (been closer to the porches), I certainly would have had at least one, if not two layers of geogrid tied back into the soil behind it to help support the load.

Right on, thanks for the thorough explanation. It's looking good. Keep up the great work!