Replies

1. 
   xMikeSmith | Mar 26, 2002 07:00am | #1

   a 3' high retaining wall of fieldstone is not much of a problem..

   if the face batters back about 5 deg. and the back side aproximates the angle of repose ( about 45 deg in normal soil ).. then it will withstand most forces of soil movement.....the aggeagate can be used to build this angle... and a filter fabric to seperate the clay from the aggregate will maintain the drainage ability of the aggregate...

   if the top of your wall is going to be 2' wide.. and the wall will be 3' high.. then the base will be 5'.... and the old rule of thumb about one stone goes on two is always a good rule..

   Mike Smith

   Rhode Island : Design / Build / Repair / Restore

2. 
   stonefever | Mar 26, 2002 07:43am | #2

   I'm a fan of drainage.  As Mike says, use the landscape fabric.  It will provide some drainage as well a keep the dirt from infiltrating the stone stack.  I prefer to go a step further and lay drain pipe at the base of the trench.  First lay down the fabric. then the pipe (perforated), pea rock to cover and then bring the fabric back around to cover that combination.  Layer strips of fabric (like tarpaper on a roof) behind the wall as you build up.  Be sure that drain pipe leads to daylight somewhere.

   The big rocks go on the bottom.  Select them so a broad flat side can go down, but also so that an attractive front face shows at the point above grade.  Rather than fill the voids with aggregate, I prefer to carefully select other stones that will fill those voids as completely as possible in such a way to distribute the loads from above evenly while providing for a stable base for the next stone(s).

   Remember this: one over two, and two over one.  Never, ever allow a vertical gap to continue up.  It weakens the wall and looks bad.  Just like a brick layer would, you must bridge any vertical gap with a stone that is supported on both below.  Good support, not just anything to bridge the gap.  That good support will be needed for the next course above.  Keep a good supply of wedge shaped stones to fill in where necessary.  From time to time, a large stone should traverse the entire distance from the face of the wall to the back.  The more often, the better.  I also prefer to have the cap stones to be large enough to extend from the face to the back as well providing a flat surface that can be walked upon.  This may sound extreme, but the true measure of the quality of a dry stacked wall should allow for it to be walked upon without having ANY stone quiver from the load.  And as Mike says, a 5 degree backward slope is very important.

   The overall design should appear homogenous.  That means an even blend of colors and shapes.  I roll my eyes every time I see a wall with big stones on the bottom tapering up to all small stones on top.  That tells me an amateur built that wall.  Such a homogenous blend will take MUCH more time as well as MUCH more rock to select from.  But the results will be MUCH more rewarding.

   The height of the wall should follow the contour of the land.  Don't make it appear as if one layer was put down and another put on top.  Make it flow together as if Mother Nature laid it down.  On the other hand, some form of signature should be employed in the lay.  For instance, in the dead center of the span, place a trophy stone that makes a statement.  For each side of it, split a large rock and position them as mirror images.  This combination should be a eye catcher.

   Finally, and far more importantly, even though I said the wall should support a walking load, extreme care should be taken to prevent anyone from doing so.  Just to the back of the wall, a fence needs to be built to prevent youngsters from driving their mountain bikes off the ledge as well as to keep you from inadvertently driving the John Deere off.  If the building inspector is going to care about anything, it is this issue.  A split rail looks perfect.

   Take your time and do it right.  If you plan on being in the house for any time, every time you drive by it, it will make your day.  And your wife will be so proud, it'll also make your nights.

1. 
   bearmon | Mar 26, 2002 04:23pm | #3

   Jon, I agree with most of what stonefever said, especially about the drainage method.  I don't agree that a fence is needed.  A planting bed along the top discourages traffic, looks nice, and gives a cleaner edge to mow to. 

   Kids will walk on the wall.  One idea I've been using lately is to use outdoor-rated construction adhesive to glue the top course to the one below, so the top ones don't move around. 

   Building inspector?  I've never seen one that cared about something like this.  It is usually considered a landscape element, and not of their concern, but you could ask.Bear

1. 
   CloudHidden | Mar 26, 2002 05:00pm | #4

   >Building inspector?  I've never seen one that cared about something like this.  It is usually considered a landscape element, and not of their concern, but you could ask.

   Agreed. Ours says if it doesn't touch the house, he doesn't care.

1. 
   byrd48 | Mar 26, 2002 05:20pm | #5

   I spoke with the Atlanta bldg inspector this morning and he does require a permit. He made no specifics about the wall itself, but said the trench beneath needed to be 12" deep ( a bit excessive I think for a 3 foot wall) but filled to ground level with gravel (normally only 2/3 filled with gravel I thought). The trench needs to be 25% wider than the wall (that's fine).

   I already have the landscape fabric and the yard will still have a very gentle slope near the wall.

   Thanks for the input, I'll update as work progresses.

   Jon

1. 
   bearmon | Mar 26, 2002 05:55pm | #6

   Jon, I'm very surprised about the permit. 

   For a paver driveway, I use 10-12" of crusher run, but that is more than you need for a typical wall.  If he insists on a 12" trench, I'd go with about 10" of base material so that the 1st stone course is partially below grade when finished. 

   Will the wall be right up to the pavers?  If so, you can do all the excavation and base work at the same time.  Do the pavers first, then lay your first layer of stone against the pavers.  Even with a narrow strip of lawn or groundcover, flowers, or whatever, it is still easier to do all the base at once, then replace a little of the stone w/ topsoil for the strip. 

   Good luck with the project.Bear

2. 
   JeffOps | Mar 26, 2002 06:50pm | #7

   Is it possible that the reason you are having to get a permit, is because you are calling it a wall ?

   Seems to me that you could simply call it a bunch of stones thrown strategicaly on the ground, and it would not matter a whit to the building department.

   It's not like you are building a free standing actual wall.

   My name is Luka.

3. 
   byrd48 | Mar 26, 2002 10:15pm | #8

   Well the permit is only $50 and I've seen quite a few "Stop Work" notices in my neighborhood, so I think the inspector has a quota in my area. At any rate, I would hate to get one of those notices and deal with it on the back end.

   As for the foundation I was originally thinking 10" trench with 6" crushed stone.

   We were planning pavers for the driveway, that's a good idea to do it at once, hadn't thought of that. I think it's time to order the backhoe and knock this whole thing out.

   Thanks again and I'll keep you posted.

   Jon

4. 
   jimblodgett | Mar 27, 2002 02:34am | #9

   It should be easy enough to find a stoned dry wall expert, wherever you work.