Replies

1. 
   HeavyDuty | Jun 21, 2003 05:30am | #1

   9' high retaining wall? Concrete blocks? No system I know of would do that. With a wall of that height, I would seek the opinion of an engineer.

   Tom

1. 
   RobKress | Jun 21, 2003 05:42am | #2

   Sure, Keystone is one of the manufacturers of these things.  Here's a link...

   http://www.keystonewalls.com/

   I just don't know if these are the best guys.... most expensive guys.... only guys..... etc.

   And yes, I have already contacted an engineer but these concrete stacking block systems look like they are "pre-engineered" as long as you follow the "rules" (well, as much as they can be anyway).

   Rob Kress

1. 
   CloudHidden | Jun 21, 2003 06:16am | #5

   There are lots of options...Mesa Block, Versa-lok...just about any material supplier can tell you what's available locally. Safety depends a lot on what you're retaining, i.e., will cars be driving on it, will structures be built on it, does the land beyond the wall slope up even more, stay level, or drop. The good systems make use of geo-grids for tying into the earth--basically a non-degradable polypropylene mesh placed every few courses on gravel and compacted dirt.

   Usually 4' does not need to be engineered, but know your local requirements. Here I could do almost any height without plans or inspections as long as it's not connected to a building. Followed the Mesa block guidelines--they'll tell ya what to do specifically for your job, if you need--and have had no troubles at all (60,000 lbs of material later). I'm specifying Versa-lok for a job because it's the locally available brand there, and that's running about $3/sf.

2. 
   ClevelandEd | Jun 21, 2003 05:43am | #3

   My gut reaction when I saw the 9 feet of height was to say "wow."   I think that even a 4 foot high wall would have to be designed to avoid an eventual outward lean.

1. 
   RobKress | Jun 21, 2003 05:56am | #4

   Really?!?!?!

   I didn't know I was trying to do anything all that crazy here.  Sure, dirt is hard to hold back but as long as the wall is engineered and installed properly.... and the hydraulic pressure issue has been delt with..... no problem.... right?

   Maybe this really is a big deal.  I guess I just didn't realize.

   Rob Kress

1. 
   bobl | Jun 21, 2003 06:18am | #6

   concrete bloclks are usually produced locally so you need to find out what is availble in your area.

   to my knowledge up to 4 ft you don't need an engineer, above that you need some engineering design.

   I've nor built a wall with these type blocks but I have built 2 sets of stairs

   Have seen the blocks used in walls up to 30 feet high, but you need design.

   these blocks have a built in set back as you build up.  geotextile is used, I believe, for the higher walls.

   as you know clay will expand when it gets wet so that can have an effect on your fill.bobl          Volo Non Voleo

2. 
   VaTom | Jun 22, 2003 03:09pm | #7

   Hi Rob,

   This is not a small deal.  I use cast-in-place concrete in making retaining walls up to 15' high.  A 9' wall with flat grade on top gets a 4'8" wide footer with a LOT (#5 on 8"c.) of rebar connecting the footer to the wall.  A sloped grade above the wall gets even more. 

   The dry stack walls have to get this strength from somewhere.  Pay close attention to how they're anchored and back-stepped.  It'll work if you do it right.  If you look around you'll see more than a few retaining walls in the process of failure.

   Good luck.  PAHS designer/builder- Bury it!

3. 
   calvin | Jun 22, 2003 04:26pm | #8

   You are wise to seek out some engineering for this project so your efforts don't go to waste.  Here you can see that darn near the sky's the limit.

   __________________________________________

   Remodeling Contractor just outside the Glass City.

   http://quittintime.infopop.cc/ubbthreads/categories.php?Cat=

1. 
   darrenb | Jun 22, 2003 07:55pm | #9

   I personally have built a 5 foot high wall with Keystone blocks and it works very well.  I have also seen several in the 30' high range out here in CA.  Just stick to the pre-engineered plans.  The compaction behind the wall is the key.

4. 
   rjw | Jun 22, 2003 09:54pm | #10

   9' high?  Stacking block?  You might want to post certified copies of your homeowners insurance on the wall so people will know they're covered.

   "This is the key, that is the key": if that sucker comes down it could kill people, and the only key worth a damn would be in the hands of your parole board.

   It's gotta be engineered. 

   In this case, my tagline is spot on: see below

   _______________________

   10 .... I have laid the foundation like an expert builder. Now others are building on it. But whoever is building on this foundation must be very careful.

   1 Corinthians 3:10

   
   

   ---

   Edited 6/22/2003 2:55:29 PM ET by Bob Walker

1. 
   darrel | Jun 23, 2003 02:41am | #11

   As other's have said, check with your local code people. Around here, any hill over 4 or 5 feet (don't remember exactly) has to have city-approved engineering plans if you're going to do retaining walls...even if you step the hill in smaller runs.