Concrete Block retaining wall

Old 07-26-16, 08:12 AM
Thread Starter
Join Date: Mar 2014
Location: United States
Posts: 94
Upvotes: 0
Received 0 Upvotes on 0 Posts
Concrete Block retaining wall

Looking to build a concrete block (standard 8x8x16 hollow cores) retaining wall. I have everything down in my mind on how the build will be, but I started wondering about the ability it would have to topple over since it's a straight wall, and not reinforced with perpendicular points or corners, say like a normal basement wall would be.

The wall will need to be 7' to 8' tall at the highest point, stepping down gradually after a solid 10' run. I intend on doing a 8" thick x 16" wide footing (trenched 3' deep for frost). Should I look into putting a couple intersecting points that would form perpendicular braces of the wall? It will be at least 20' long, so picture a 20' long 8' tall (stepping down after 10') concrete block wall...seems like it may be apt to fall over after a good 15 to 20 years.
Old 07-26-16, 08:52 AM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 45,724
Received 850 Upvotes on 746 Posts
I'm pretty sure a retaining wall of that size would need 12" block with some of them filled with concrete/rebar. You also need to provide for drainage behind the wall. The backside should be waterproofed if you intend to put any finish on the front side.
Old 07-26-16, 09:39 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 27,939
Received 2,222 Upvotes on 1,983 Posts
I would not even consider building a CMU retaining wall. They must be done properly to avoid problems. Much easier, more reliable and more attractive are pre-cast concrete blocks that are dry stacked to form a retaining wall. I use Keystone but there are other brands of engineered retaining wall blocks. Do NOT consider retaining blocks you find in most home centers no matter what they say.
Old 07-26-16, 12:33 PM
Join Date: Mar 2005
Location: USA
Posts: 5,650
Received 1 Upvote on 1 Post
Pilot Dane was best choice without a doubt if you want a 7' to 8' high retaining wall and you can tolerate a very slight batter of the exposed face. These units are NEVER laid on a concrete footing and any warranties are void if a concrete footing is used.

To find availability, check with your city or county to see what brand they use and it will probably made reasonably near-by and you can follow the manufacturers installation suggestions that avilable on-line.

Unlike the common 8x8x16 blocks, the SRWs and made to be attractive and exposed and are usually available in colors and with split textured face. The appearance is one of they units these are used on road and sidewalk modifications by municipalities because the look far better than plain-Jane concrete.


Thread Tools
Search this Thread
Ask a Question
Question Title: