DIY Home Improvement, Remodeling & Repair Forum > DIY Home Improvement > Bricks, Masonry and Concrete > Landscape Block Wall

Help Support House Repair Talk by donating using the link above.
Thread Tools Search this Thread
Old 09-17-2017, 04:58 AM  
Join Date: Apr 2012
Posts: 64
Liked 2 Times on 2 Posts
Likes Given: 30

Default Landscape Block Wall

I'm planning a small landscape wall to alter the drainage around my house. It will be ~3 ft tall tapering to 2 ft over a span of 11 ft before ending.

I plan to use the stone pictured in the attachment.

How many inches do I need to excavate behind the wall? I plan to back-fill with large gravel (#57 stone). If I use #57 stone, do I really need a drain pipe as well? I plan to protect the backfill with landscaping cloth.

In your opinion, is it worthwhile to fill the voids in the block with gravel? Will it make the wall more sturdy?

Thank you!

Click image for larger version

Name:	6c7c4253-97cf-41fa-bda3-72982fd049e4_1000.jpg
Views:	40
Size:	135.0 KB
ID:	14656  
soparklion11 is offline  
Reply With Quote
Old 09-17-2017, 07:44 AM  
Senior Member
Join Date: Sep 2006
Posts: 2,745
Liked 472 Times on 419 Posts
Likes Given: 1


Garden walls higher than 2'6" are considered to be retaining and should have an appropriate footing, rebar and grout, as well as the appropriate hydrology drain.

Generally the french drain is placed behind the first coarse, encased in gravel and the excavated slope backfilled.

What is the slope of the excavation? 1:1 is a 45 degree.

Illigitimas non-carborundum
Snoonyb is online now  
Reply With Quote
Old 09-17-2017, 09:28 PM  
slownsteady's Avatar
Join Date: Jun 2009
Location: Newton, NJ
Posts: 6,455
Liked 1160 Times on 962 Posts
Likes Given: 1905


That may be California rules only, but it pays to check for any local code.
You only need to have enough room behind the wall to work comfortably, but you should go low enough to put in a good solidly tamped down gravel bed. If your objective is to alter the drainage, don't cheap out by skipping the french drain. Bury the fr. drain and the first course and back fill with gravel as you go up. I'm not familiar with #57 stone, but you don't want to have large voids between the stones...they will fill with something on their own. You don't have to fill the voids in the block, just factor in a top row of cap stones which can be glued down with landscape adhesive. Anyways, that's how I would do it; local conditions may influence how you make it happen.
Learn something every day
slownsteady is online now  
Reply With Quote
Old 09-17-2017, 09:32 PM  
Senior Member
Join Date: Sep 2006
Posts: 2,745
Liked 472 Times on 419 Posts
Likes Given: 1


Hydrology affects all retaining walls.

Fail to address it at your own peril.
Illigitimas non-carborundum
Snoonyb is online now  
Reply With Quote
Old 09-17-2017, 09:39 PM  
Contractor retired
nealtw's Avatar
Join Date: Nov 2010
Location: Upper Fraser Valley, British Columbia
Posts: 23,705
Liked 3052 Times on 2671 Posts
Likes Given: 5040


I like allan blocks more because the lip on the front helps getting th slope back angle right.
I think you can go 36" with them before you need an engineer.
nealtw is online now  
Reply With Quote
Old 09-18-2017, 02:33 PM  
mudmixer's Avatar
Join Date: Sep 2006
Location: St. Paul/Minneapolis, MN
Posts: 669
Liked 76 Times on 59 Posts
Likes Given: 72


Soparklion11 -

That unit you show is really not a good unit for a retaining wall unless there some secret hidden in or behind what is seen.

When you lay a conventional shape block like that on top of another, the block can just slide with any soil pressure below and any soil crumbs act just like oil to lubricate the surfaces. - Rock in the cores will help a little, but it still cannot be considered a "retaining wall unit" by any stretch of imagination. - You need some sort of key or projection to maintain stability.

The Allan Block is one and I have also seen others that had a "lip" or key on the lower back of the block and served the same purpose.

There are many other units (the good licensed products and even the "knock-offs) will work for your situation, but a lot of the "knock-offs" lack some features. - Stick with the good units.

Most codes to require some sort of engineering for retaining walls over 4', but then you get into soil reinforcement (geo-grid, etc.).

In my 40 years experience in the block business, I made most of the major block used for testing and approval purposes plus a few other types that never succeeded.


Last edited by mudmixer; 09-18-2017 at 02:36 PM.
mudmixer is offline  
nealtw Likes This 
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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

Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
Allan block wall leaning nealtw Bricks, Masonry and Concrete 5 06-30-2017 03:53 PM
Filling gap in block wall beachguy005 Bricks, Masonry and Concrete 1 05-02-2013 05:04 AM
Wet Block Wall andrea&tom Bricks, Masonry and Concrete 6 02-15-2009 12:25 AM
Block Wall Jose119 Garage & Workshop Forum 0 08-28-2008 12:37 PM
Filling Big Hole in Block Wall hurbear Bricks, Masonry and Concrete 4 03-02-2008 12:57 PM

Newest Threads