What does "retaining wall" mean to you? A flat, stacked and mortarless masonry wall is not a retaining wall, since it has no means to resist overturning moments.

Both wall types would use mortar. In that scenario, which is better?

You'd probably be better off with a locking keystone type retaining block. CMU isn't all that good, and the real rock will be VERY dependent on the installer. They actually make a decent locking block that looks like stacked stone...

Again, it all depends on your definition and needs for a "retaining" wall. How high will the wall be? What will it be retaining? Are there expansive soils and/or high water content? Or is it simply decorative and not really a retaining wall at all?

Thanks, Virgil! 3 feet high, real retaining wall. Retaining between the higher front yard and lower back yard. Ther will be water. Doesn't pour but would need standard drainage. In that scenario, what would be best?

jannicone, With proper drainage CMU would still be bad? The walls the mason does "look" good.

"...In that scenario, what would be best?..." There are various designs for retaining walls which will all work, but based on local conditions. Three feet high is not excessive and properly designed and reinforced CMUs should work. In all cases, however, retaining walls are not simply "masonry walls". Proper design includes provisions for reinforcement/anchoring and water drainage. Proper backfill is also important. What do your local "experts" suggest?

Google "retaining wall" and see how your situation fits into common designs.

Excavate area at base of walls to a depth of approximately 18-20"

Backfill with ¾” crushed stone & compact & install filter fabric

Backfill behind walls with approximately 5-7” riprap or construction material to enable proper drainage

Construct CMU retaining wall with stone veneer with desired appearance on visible vertical faces with hidden concrete to bond stones & ensure stability

Install granite caps that overhang

re "properly designed and reinforced CMUs should work" but would fieldstone be a better choice.

Best practices being equal, my vote would be fieldstone. Better yet, find a mason who prefers working without mortar, like those from this dry waller map. Your region is blessed with many well trained wallers!

In our area, experienced graders can do decent looking boulder walls that don't rely on mortar or concrete.

why fieldstone? don't they have issues without mortar for holding back dirt, and with drainage over time?

Also- thanks Springtime! :-)

Certainly wouldn't ignore creeping or colluvial site conditions but had more of this in mind with dry-stack masonry, the longest lasting architecture available?

Shingle style home in Hanover NH · More Info

Gardens with a view · More Info

River's Edge · More Info

Dry stack masonry is lovely to look at, no question. But even with concealed mortar joints there's just no strength there to deal with the lateral forces of soil creep, hydrostatic pressure and strong overturning moments.

Decide whether the priority is for initial beauty or longevity.

Actually, one can have both, but only with proper soil analysis and structural design.

Just to be clear, all three walls above are described as dry-stack, which typically use zero mortar, concealed or otherwise. Dry-stacked rocks comprise the oldest surviving architecture on the planet.

Most site grading with topography doesn't necessarily require a geo or civil engineer. Walls abutting a home and over four feet are triggers in our region.

For those unfamiliar with the traditional dry-stack stone walls and fences of New England and the old world, the dry stone trust is a nice resource. That tradition uses readily available and mostly smaller rocks. The more permanent stuff is bigger like that used by Egyptians, Greeks and my personal favorite the Incans.

Thanks to everyone. Virgil Carter Fine Art is right, there's an uphill slope behind the retaining wall. "Reinforced CMU, installed on a foundation with proper backfill and drainage" is it then. Thanks!

update: We had thought the mason was clear that we would use CMU with a stone veneer, but now they are proposing what is in these photos. Is this going to be OK for drainage and structurally?

A rubble wall (with a stone face), on compacted (?) gravel fill (no poured footing), with no reinforcing and no provision for drainage away from the fill? And what will be the height when finished?

Hi, Virgil- that sounds/looks like what they are doing (they compacted the earth underneath the gravel). No poured footing. 4 feet high. What reinforcing and drainage should there be?

Any advice appreciated. They will be putting crushed stone behind front stones, and in front of black fabric.

Photos of concrete poured to hold front and rocks together. Behind rocks against fabric will be crushed stone, gravel.

What part of the country are you building in? Does it freeze? Lots of rain?

Expansive, clayey soils?

Post a pic in a couple of years. Should have a very rustic look by then.

I don't believe this is prescriptive!

Another good thing about retaining walls like this is that one gets to renew them every few years, and keep local masons in business...

New England, sandy rather than clayey soils. Not really looking to sustain local masons in the short-term..... So the way they are doing it will not last?

If you were building a house and digging footings, how deep would you dig?

The wall needs to sit on a footing below frost depth.

I'd be building something like this, with proper drainage behind and faced with your choice of material.

Re. frost line: Since what my mason is doing is basically a dry stack wall; from here: http://www.doityourself.com/forum/lawns-landscaping-outdoor-decor/451549-frost-line-retaining-wall.html#b

A dry stack wall does not matter. The joints have enough space to allow this heaving movement. The large spacious joints in a dry stack wall are like expansion joints in other strucures, they will take movement.

versus

How did it go, stigwort_berry?