Stone Walls: Dry vs Wet

Dry vs Wet laid Stone Walls:

One of the first questions many homeowners ask when proposing a new stone wall is whether the wall should be built with or without the use of mortar.  (A “wet” stone wall uses mortar, while a “dry” stone wall does not). Different factors can effect this decision, but we at Concord Stoneworks will most often recommend a dry stone wall.  In this article we will discuss why this is so and the advantages and disadvantages of either option.

split face stone wall

Mortared Stone Wall – Split Face Stones

A wet stone wall is designed as a rigid structure.   When external forces are exerted on the wall, (ground settling, frost heaving, errant snow plows, etc.), the wall is designed to withstand the forces and hold its form.   A well-built, mortared stone wall with a solid base and backing will hold up for quite some time, yet, it is inevitable that at some point movement will occur. When it does, and when the forces become too great for the wall to withstand, the material cracks. When this occurs the repairs are not easy. Patchwork will be unattractive and do little for the structural integrity. Rebuilding the wall or portions of it will be labor intensive and may require all new material.

On the other hand a dry laid stone wall is flexible. Water drains through it naturally, and any minor settling or shifting that occurs is absorbed by the wall and goes largely unnoticed. Even if major failure does occur for some reason, the wall or portions of it are easy to dismantle and rebuild using the same material.  Repaired portions will also blend seamlessly into the existing wall.

Drystack Stone Wall - S. Windsor, CT

Drystack Stone Wall – S. Windsor, CT

One of the advantages of a mortared stone wall is that it is easier to achieve a high level of finish. While building the wall, the mason can rely on the adhesive properties of the mortar to hold the stones in place. This makes it easier to focus on facing the wall to create a very flat and consistent finish.

A dry stone mason uses gravity only to hold the wall together.   Each stone is laid with structural integrity in mind. Instead of facing the wall with a stone’s flattest face, the stones are stacked so that the heft of the stone ties back into the wall and holds everything together. This produces a more rustic or traditional look. Extremely high finish dry stone walls do exist, but they take extra time and care to produce.

Lastly and most importantly, it is often less costly to build a dry stone wall. Wet stone walls require a rigid concrete base, mortar for the wall and the machinery/labor to mix the mortar, and proper drainage.  This additional prep work is necessary to try and prevent any movement.

Dry stone walls on the other hand are built with a simple gravel base and backing. They require no additional drainage and the only material needed is the stone itself.

Dry stone walling is a unique skill that not all masons fully understand and appreciate.   Although there is a time and place for wet stone walls, we at Concord Stoneworks much prefer the aesthetic, function, and efficiency of a dry stone wall.

 

Bluestone Walkway and Granite Steps – Boxborough, MA

At this home in Boxborough, MA an old bluestone walkway had come out of level and the stones were breaking apart.  Also the bluestone steps had come loose and were unstable.  The homeowner wanted to replace the walkway with new bluestone and use solid granite steps.

For this project we removed the existing bluestone and excavated below.   Whenever possible we will excavate by hand in order to preserve the surrounding landscape and minimize/eliminate extra costs for sod repair that can arise when machines come in.

Here we have excavated the area to depth of 8-10″ to allow for new base material.  The new walkway will go in the same footprint as the old.

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excavated stairway

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excavated walkway

Next we install the granite steps.  The steps are dry laid on a bed of crushed stone and a thin layer of stone dust to achieve level.   One step goes in, we back fill behind it to meet level, and the next step is stacked on stop.  The adjacent wall has to be partially dismantled to make room for the new steps.

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granite step installation

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granite step installation

All nine granite steps are set.  With the steps in we have a guide for the level of the walkway portions.  We’ve carefully planned the upper steps so that the finished height of the walkway doesn’t sit too high above or too low below the grade of the adjacent sloping lawn.

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granite step installation

Next we finish compacting the subgrade and filling the base with crushed stone to prep for the bluestone walkway installation.  The crushed stone provides a solid base that readily drains water.   A layer of stone dust is used to set the bluestones in and achieve the fine tuned level.

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bluestone walkway prep

The bluestone is installed, stone dust is swept in the joints, and some soil is added to the edge to regrow grass and meet the level of the stones.  The bluestone used is natural cleft, full color range.  It comes with it’s irregularities, but produces a handsome and slightly more rustic finish than the more finely treated varieties of bluestone.

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completed bluestone walkway and granite steps

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completed bluestone walkway

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completed granite steps

Fieldstone Wall Repair – Westford, MA

This fieldstone wall in Westford, MA was damaged after being struck by a fast moving vehicle.  The car careened off of the first wall, narrowly missed the house, and then struck another stone wall further down the property.  Fortunately the driver was able to walk away from the incident.

The homeowner found our website and hired us to rebuild the damaged portions of the dry laid stone wall.  It was also a convenient time to tidy up some of the other portions of the walls that had deteriorated over time.

Fieldstone wall damage - Westford, MA

Fieldstone wall damage – Westford, MA

One of the advantages of a dry laid stone wall such as this is that when damage does occur, be it from a vehicle or snow plow or just ground movement and frost heaving over the years, the repairs are fairly inexpensive.  The stones can be easily dismantled and then re-used in the same style.  Often it is hardly apparent that any repairs took place at all.  Had this wall been laid with mortar, the repairs would have been much more extensive.

Farm wall damage - Westford, MA

Farm wall damage – Westford, MA

The larger wall above and to the right is of a rougher style – often how you see old farm walls. Farmers would pull stones out of the field and quickly and roughly stack them at the property line.  Emulating the same style and method, we were able to tidy up this wall and re-stack the stones that had come off.  Without bringing in machinery and tearing it all out and rebuilding a higher finish wall – were were able to clean up this stone wall by hand in short time.

Farm Wall - Westford, MA

Farm Wall – Westford, MA

The other wall being of a higher finish took a bit more care.  For this we first dismantled the damaged portion and then rebuilt.  The fieldstones were laid in the same style, making an effort to re-use aged/lichen covered stones on the surface in order to maintain the aesthetic of this old New England stone wall.

Fieldstone Wall Repair - Westford, MA

Fieldstone Wall Repair – Westford, MA

The result came out well and to the untrained eye it is hardly noticeable that any repairs took place at all.

With a days work, we at Concord Stoneworks were able to make big improvements while preserving the traditional aesthetic of these New England fieldstone walls.

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fieldstone wall repair

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fieldstone wall repair

 

Fieldstone Wall - Westford, MA

Fieldstone Wall – Westford, MA