[average_male]

Hello All,

I am going to put up a 2 foot (height) retaining wall to maintain a 1 foot grade offset between my neighbors fence and my yard.

Question: Do I need to lay down a cement foundation for these cinder blocks to rest on or can I simply tamp and level crushed rock and lay down my cinder/motar on that?

Thanks,
Moe

 

[kyassassin]

I would use the retaining blocks with the lip on the back that you can find at HD or Lowe's. Use a little heavy duty glue between each block and it will easily hold a 1 foot grade with no cement and no footer.

Here's a project I finished this spring...

 

[average_male]

thanks for the reply. That looks very professional yet simple as no footer, cement, rebar etc was needed. However, there is something about the tapered look that won't fit my yard. Do they make such blocks that have a flush side (front)?

 

[beranbr]

Yes you can build a 2' high segmented retaining wall without stepping the blocks back, but that is the max. you can go before needing geo-grid.

Here are some pictures of some jobs I have recently completed:

 

[beranbr]

Another:

 

[beranbr]

By the way, I do not use anything from lowes or homedepot. The retaining wall blocks they carry are more or less simply garden walls and not to be used as a full blown retaining wall. You need to find a local stone or hardscape center that carrys EP Henry, Techo-Bloc, Hanover, Nicolock, Allan Block, or something of the like.

At 2' foot high you will need (not optional) a 4" perforated pipe that is vented to day light located behind then wall in the base trench for drainage and I would backfill 18"-24" behind the wall with 57 stone and machine compact in 6" lifts to consolidate. Do this all the way until you reach your last course of wall block and then use soil to finish the backfill. Not using a drain pipe and backfilling with on site soil and not stone will most likely result in a failed wall that come tumbling down.

 

[average_male]

beranbr,

That looks amazing. Exactly the thing I am looking to do. Quick questions, if I may:

1) What of the concrete foundation for a 2' wall, is it needed?

2) In the first picture you posted (the L-shaped retaining wall), did you use motar to build the wall? Can't tell by the picture.

3) In your reply: "I would backfill 18"-24" behind the wall with 57 stone and machine compact in 6" lifts to consolidate."

What do you mean by '6" lifts to consilidate'? Does that mean compact the 57 stone every 6" (inches) until I reach the target 18"-24"?

4) Do I need to go the height of 18"-24" of 57 stone if my wall is going to be 3 feet from my property line, can I go with less compated 57 stone height? Also how far back should I back fill with the 57 stone? That is, what is my width of the drainage channel?

5) Do you recommend drainage sheet/tile between the 57 stone and the wall?

6) I have a manual tamp, I know it will be a lot of work, but can I use that to compact the 57 stone? Or will I not get the compation needed if I do it by hand?

7) Did you use stone veneers in your installation?

I really like the lighting features of the installation, must look very inviting in the evening.

I really appreciate your input and look forward to hearing from you soon,
Moe

 

[beranbr]

1. No concrete footer. Dig a trench 18-24" wide by 12" deep by the length of your wall. Machine compact the bottom of the trench, lay down geo-textile fabric if there is a lot of clay or you think you need extra reinforcement, then machine compact 6 inched of crush and run in 3" lifts. Then your ready to lay your base course, leveling each block front to back and left to right and level with each block next to it.

2. No mortar is used in either wall. Just a masonry adhesive or some manufactors supply pins, but masonry adhesive is much easier to use.

3. I mean you need to backfill from the back of the block 18-24", 12" is required but if you want the wall to last I would go 18-24" because there is no geo-grid. By 6" lifts I mean fill the void behind the wall which is going to be 18-24" wide 6" deep which is usually one or two courses depending on if you are using 3" or 6" high blocks. By consolidate I mean use a machine plate compactor to tamp the 57 stone. You can use a hand tamp to do so but it may take you a LOOOOONG time. 57 stone will not reach a high compaction rate because there are no fine particles to fill all of the voids so you are just consolidating the stone.

4. No stone veneer was used, but I intall that too. Mainly on cinder block walls or other masonry materials.

Hopefully I have answered all of your questions.

Here is a complete guide offered by allan block retaining walls. I highly recommend going through and reading everything. There are also videos on their website.

http://www.allanblock.com/RetainingWalls/Installation/Landscape/intro/intro.aspx?ta=1&product=rt

 

[average_male]

beranbr,

Thank you for the follow-up. You answered every question I had with great detail. Thank you so much for your time and knowledge, it's greatly appreciated.

I have heard a lot about Allan Blocks, they come up all the time on YouTube when searching against 'retaining wall'

Thank again,
Moe