Retaining wall help/advice


Old 06-11-15, 11:16 AM
Thread Starter
Join Date: Jun 2015
Location: United States
Posts: 1
Question Retaining wall help/advice

Hi everyone, this will be my first post to this forum, and I apologize in advance for any mistakes.

Before i continue i understand this is a HUGE HUGE HUGE project for me but id like to try, and am prepared to spend the next few months working on it if needed, if i happen to fail or quit, i am prepared to take the loss and hire professionals, but this is just way more fun and satisfying!

I've done a ton of research, but have a few remaining questions, And would greatly appreciate your help, review of my process, and any advice.

Id like to give you a short explanation of what im dealing with:

I live on a VERY steep slope on one side, and the dirt has been eroding for quite some time now, We moved in 2 years ago, and i can only assume that its been eroding for over 10 years. (my best guess is that the slope ranges anywhere from about 50-70 degrees, and is about 15 feet high/tall from the street, and 50 feet wide and about 15 feet deep, from the sidewalk to house)

Since it is a home project, I am planning to build two (or more) 4 foot high retaining walls, with at least 1-1/2 block beneath the ground, with the base consisting of 3-5 inches of gravel, followed by 2-3 inches of paver base/sand. (i would also have a perforated drain hose under the the gravel.

Do you think this would suffice? Or am i going about this wrong?
I understand that even with two walls, id only be up to about 8 feet high, while the slope is around 15 feet tall.

What type of wall blocks would you recommend? Solid, hollow, other, or would it not matter?

Next question is regarding the landscape fabric, i noticed there are so many, and im not sure if it matters. Many of them advertise weed prevention and im guessing that doesn't matter since its only used to hold back the gravel and dirt.

finally, would i need to use adhesive or mortar to glue each block, or would the weight be enough to keep the walls in place?

Any and All advice/input is appreciated!

Thank You!
Sponsored Links
Old 06-11-15, 11:57 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 20,083
Likes Received: 101
I would use a dry stack retaining wall block. Not the small ones you find at home centers but the larger, engineered ones intended for structural retaining walls. I use Keystone but there are many others. They have very detailed installation instructions for varying situations.
Old 06-11-15, 12:32 PM
Join Date: Mar 2005
Location: USA
Posts: 6,130
For 15' high and 15' deep that is a HUGE, HUGE, HUGE, HUGE project and not a DIYer job because the potential weather problems over the construction time needed. Once the digging (at the bottom) starts you are at the mercy of Mother Nature and many places in CA can turn a shower into a disaster for everything above and below the wall.

As a minimum, get a Geotech engineer to give you a preliminary sketch to get you planing on how to do it and move the soil. - You will need equipment to excavate, fill, bring in materials (gravel and suitable fill).

You may also run into some zoning and code situations even in remote areas. - It is hard to hide a 15' high structure when the trucks/trailers and equipment move.

I suspect that with building 3 walls with a surcharge from above you would have a hard time spacing them far enough apart since the slope is great above and puts pressure on the walls below.

I worked as an engineer in CA and have some big disasters when one of the rare showers comes and erodes a lot of material in a short time. If you are in a foothill area, that can be a bigger problem.

It is a project best suited for real retaining wall block (not landscaping block) as compared to a rigid reinforced concrete wall that can involve more dirt moving and construction cost.


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes