North Asheville Retaining Wall

 

North Asheville Retaining Wall

North Asheville Retaining Wall

This large drystone retaining wall replaces an old block wall that was being slowly pushed outward by hydrostatic pressure. Located in a quiet North Asheville neighborhood, this is the largest single wall Hammerhead’s done to date, at over 300 square feet. The yard slopes quite a bit and so the wall had numerous steps in it, as the wall maintains the same relative grade as it goes down the road. This is practical too, as it ensures that the wall is never taller than 48″, the maximum allowed by code before engineering is required. The wall is built of 30 tons of Hooper’s Creek, a locally quarried granitic gneiss.

North Asheville Retaining Wall

Biltmore Forest Stonework: Retaining Wall

Boulders and drystone retaining walls blend together seamlessly in this Biltmore Forest stonework project built by Hammerhead Stoneworks.

 

Biltmore Forest Stonework: Before and After

This pair of images show how this stonework project evolved. The boulders were already in place, but ineffective at slowing erosion on the bank above. Mulch and leaves were constantly washing into the driveway. We decided for aesthetic and cost-savings reasons to leave the largest boulders and build our retaining walls to meet them. Smaller boulders were removed to make way for the retaining walls.

The space before

The space after

The space after

Stonework Project Getting Started


This image shows the calm before the storm. There’s about 9,000 pounds of stone there, (more than we need, but there are other projects planned we will use the excess for.) This is a drystone wall. Note the black geo-textile drainage fabric laid over the exposed bank. This fabric allows water to pass through, but captures silt and other fine particles that would wash through the wall. Drystone retaining walls are more beautiful and more durable than a mortared wall installed in the same situation. In effect, the whole wall is a drain, allowing rainwater runoff to pass through. Hydrostatic pressure never builds up. Hydrostatic pressure is a powerful force and is responsible for pushing over so many of the older, mortared retaining walls that we see around Asheville.


This image shows us making progress on the lower wall. The string line is level across, though the wall shrinks and grows as the driveway rises and falls.

Stonework Project Details

We used a metamorphic stone called gneiss, quarried in Fletcher, North Carolina. It’s a native stone and looks just right used for landscaping walls like this one. All of the stone is laid in its bedded plane, meaning the stones are set laying the same way they were formed. Face bedding (standing up) a stone like this can result in major problems, as water can work its way into the stone and cause layers to delaminate and peel away. In the background you can see a rough old wall, a jumble of stones really, that will someday soon be replaced with a wall like this one.

Water Feature, Stone Paths, Steps & Bench

Asheville stone masons Hammerhead Stoneworks recently completed this water feature with a natural stone bench, paths, drystone walls and steps.

Dry Stone Paths & Steps

This dry stone pathway connects the homeowner’s driveway with their favorite hangout spot, on their back deck. A single slab of sandstone provides an easy step up to the deck. The regular shape of the slab lends an air of formality to the entrance, sometimes used by guests. This serves as a counterpoint to the more natural looking stones that make up the adjacent steps, walls, water feature and bench.


The bench is found at the bottom of the water feature. It is very organic, a natural slab with a patina of lichen. The area is fairly shady and so I am hopeful that the lichen will survive. Two rugged boulders were topped and anchored in concrete to provide the bench supports.

Water Feature Before and After

 

This pair of images shows how we transformed this unused space. The drystone retaining wall at the bottom raised the overall grade. This allowed us to hide drainage pipes running from the house’s many downspouts. We used heavy duty solid white PVC pipe to extend the drain pipes. Though more expensive, these pipes have never failed me. Everytime I have dug up a black corrugated drain pipe it is either collapsed, perforated or clogged. Or all three. Next spring, once the plants have been chosen and given time to establish themselves, this will be a lovely view.
Click on the image above for a larger view of the water view and overall design.

Coming soon: more pictures of the water feature itself.

Drystone Pathways Over Bad Concrete

Drystone Pathways Over Bad Concrete

A broken down piece of concrete magically disappears under a stone pathway laid without mortar or cement.

Drystone Pathways

I am frequently asked to remedy concrete walkways. Sometimes these concrete paths are old and broken down, in other cases, they just aren’t the look the homeowner desires. In most situations, the existing walkway, broken down or not, needs to be removed. This can be expensive and bad for the environment, if a good use can’t be found for the broken concrete. Whenever possible, I try to leave the concrete where it lays and place my stone over it. Dry laid flagstone is stronger and more durable than mortared paving, and it doesn’t matter how messed up the concrete is underneath it. (Mortared flagstone should only be applied to solid slab in good condition.) Laying drystone flagstone over ugly concrete saves money, and avoids filling the landfill with concrete waste. There are two main issues that can come up when taking this approach that we’ll explore below: clearance and drainage.

Drystone Pathways

BEFORE: This little used path wrapped around the back of a lovely Asheville home. The homeowners wanted to pretty it up and maintain access to their backyard.

Drystone Pathways

AFTER: A loose stone pathway winds its way through a field of pea gravel. Instead of removing all the concrete, I placed my flagstone over the top. Stucco became a quick fix for this ugly wall. You might see that it’s being pushed over by the bank behind it. Someday we’ll replace it with drystone!

Dealing With Drainage & Your Stone Pathway

Drystone pathways and patios allow water to run over them and percolate through. This prevents pooling and reduces slick spots on the walking surface. It’s important that the top surface of the stone pathway be able to slope gently away from houses, foundations or other areas sensitive to moisture build-up or erosion. It’s equally important that the substrate below the flagstone is also pitched in the proper direction, as some moisture will pass through. This means, when I go over a concrete walkway with stone, I have to be sure the slab is draining in the right direction. This is easily assessed with a level and tape measure. A host of solutions can be considered if the drainage situation isn’t ideal.

Clearance Issues For Flagstone & Steps

Clearance issues are usually the deal breaker for whether a dry stone surface can be laid over concrete. The height of existing thresholds, curbs or steps must be taken into account at all points along the flagstone surface. The risks being that one could create weird little steps, make a trip hazard, or block a door so that it no longer opens! As it happens, so much settling occurs in Asheville homes, old and new, that I can often find the clearance I need, sometimes by replacing awkward and uneven steps with stone stairs that are uniform and solid.

Drystone Pathways

In the image above, the large stone slab that acts as a step was the key to getting the clearance needed to build the path that circled the house. Previously there had been an awkward three inch rise- too tall for a threshold, but not tall enough to be a step. This stone step, at six inches tall, is a real step, consistent with those at the street and that lead into the house.

BEFORE: A broken down set of uneven concrete steps lead to the street. There’s a fourth step hidden in the shadow of the telephone pole. The top step is coming apart and is off center with the steps below it.

Drystone Pathways

AFTER: I had to tear out the bottom three steps, but that was the only concrete removed for the whole project. (Reclaimed by a friend who needs clean fill for another project.) I set the steps further back from the road and gave them a consistent rise over run. I rebuilt the wall, opening the main entryway and making it more welcoming. The steps are now aligned with the path. The steps and wall repairs are mortared; everything else is laid dry.

The homeowners are both craftspeople- he’s a woodworker and she’s a potter. As we stuccoed this old block wall, we embedded ceramic tiles made by the potter. This is a picture of my favorite, a relief print made from a gravestone carving she found at Riverside Cemetery.

Drystone Retaining Wall: Downtown Asheville

retaining wall

Springtime wall

I built this drystone retaining wall a couple of years ago, just outside of downtown Asheville. I like to visit it when I can and I have been working in that neighborhood lately (more updates to follow.) My friend Betty Sharpless, owner of Good Help Landscaping, maintains the site and is responsible for these beautiful irises. The wall is made of a variety of sandstones from Tennessee and Virginia with some Pennsylvania bluestone thrown in for fun. See more pictures of this wall here.

Benefits of a Drystone Retaining Wall

A well-crafted drystone retaining wall will have a smaller carbon footprint and will outlast a similarly sited mortared wall. Here are some of the other advantages of drystone masonry:

  • Flexible, moves rather than breaks in response to outside stresses
  • Drains water effectively, preventing build up of hydrostatic pressure, the force that pushes over mortared walls
  • Doesn’t require concrete footings or slabs or block wall backing
  • Weathers better and lasts longer
  • Easier to repair work or reuse the stone at a later date
  • Requires no waterproofing
  • Looks more natural in the landscape

Read more about drystone here.

Springtime!

drystone retaining wall with water meter cover

Water meter cover embedded into a drystone wall.

I built this drystone retaining wall in a neighborhood just outside of downtown Asheville last summer. It’s come into its own this spring with the arrival of dozens of tulips. This manhole cover detail is one of my favorite things I built last year.