Small retaining wall and fence


  #1  
Old 04-11-08, 05:29 PM
T
Member
Thread Starter
Join Date: Apr 2008
Posts: 1
Upvotes: 0
Received 0 Upvotes on 0 Posts
Small retaining wall and fence

I live in the northeast and need to put up a standard 6'-0" fence. First i want to pour (or lay) a retaining wall that comes up about 12" from the ground. The fence posts will be drilled into the wall. My question is how deep below the ground does the wall need to be? Does it need gravel/stone and rebar? Like I said it is just a low wall to give seperation from the ground, which is flat and the retaining wall will not hold much back.

Thanks
 
  #2  
Old 04-11-08, 06:18 PM
Join Date: Mar 2005
Location: USA
Posts: 5,650
Received 1 Upvote on 1 Post
Small retaining wall and fence

If you build a mortared restaining wall or a poured retaining wall (both are rigid walls), you should have footings below the frost line to prevent frost heaves. You can find this information from a local building official or some on-line maps for frost penetration.

You should also have the right backfill that drains well to prevent lateral heaving.

You can then attach to the walls if they are thick enough for drilled posts or the wider bolted base plates.

If you use a segmental retaining wall (Allan Block, Anchor Wall systems, Keystone, Versalok - all have sites)), no footing or mortar is permitted because the wall is inteded to moove very slightly since there is no cracking. The problem is that any fence posts will have to be set in soil slightly behind the wall.

Dick
 
  #3  
Old 04-11-08, 07:08 PM
N
Member
Join Date: May 2002
Location: Maryland zone 7
Posts: 1,654
Upvotes: 0
Received 0 Upvotes on 0 Posts
Hi Tomgee,

You'll need to know the frost line depth where you live. For that contact a contractor or your local building inspector or permits office. If you don't dig below the frost line you risk heave and your fence toppling over. You may need a permit for a fence over 6' as well. Here's how to build a basic retaining wall. Yours would have to be mortared as a dry stack wall won't be sturdy enough to mount a fence on.
http://www.highplainsstone.com/ideas/drystackwall.shtml
http://www.irwinstone.com/howto_stonewall.asp

Newt
 
  #4  
Old 04-11-08, 07:20 PM
Join Date: Mar 2005
Location: USA
Posts: 5,650
Received 1 Upvote on 1 Post
Small retaining wall and fence

Newt is right about not attaching to a segmental retaining wall (SRW) wall. They are not designed to have the block mortared together. In your area, your frost depth may be more than the height of the wall you desribed. An SRW wall usualy requires about 2 feet of excavation for a gravel base and erosion protection. For your 2 foot wall a permit probably is not required unless there are requirements if drainage is changed.

There are some patented probucts available to install posts behind a SRW wall, but I am not aware of the eaxact names. You could Google or ask a supplier.

SRW walls are, however, very sturdy and preferred by highway departments and municipalities for many applications because of the economy and slight "give" in the wall. The biggest SRW wall I have seen was 3 sections covering about 5 miles with the height varying between 1 foot and 30 feet. The highest I have seen was 45 feet, so the are certainly substantial and "sturdy".
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: