No, that’s not a trick question. The obvious answer is “a seat wall is a wall to sit on”. That’s true, but I wanted to bring up some additional aspects of a seat wall.  For instance, what other functions do they serve and what else should you know about them?

In its simplest form a seat wall is generally built at a comfortable sitting height – somewhere around 18″. Like any wall it should be solidly built. The top or “capstone” should be level, substantial and secure. These walls see action – so give them the build integrity to deal with it.

Although many seat walls are built with two finished sides (i.e. front and back), some are also serving as a retaining wall (with one finished side). In the picture above this is the case.  This patio seat wall is supporting a raised garden.

However, as the grade level slopes down, the back of the wall becomes exposed. It’s now necessary to segue into two finished sides (picture at left).

What material options are there to build a seat wall?

Almost any material used for a wall in the landscape would work for a seat wall. But here are a few to consider:

• Natural stone: This is my personal favorite. Natural stone can be dry-stacked or installed with cement.
• Masonry Block With Veneer or Stucco: There are numerous veneers made of real and artificial stone that can be applied over a conventional block wall.  There are also stucco finishes that can be applied.
• Precast Modular Block: These are the manufactured wall systems.  Not my favorite choice for looks because I’m concerned this material will become outdated.

For Design and Purpose

Here are some functions and benefits served by a seat wall besides seating.

• Retaining Wall: I mentioned retaining wall use for the patio design above.
• Create An Outdoor Room: Any vertical element can help suggest a separate space or room.

• Integrate With Another Feature: such as a fire pit, water feature or outdoor kitchen.  You can also use a seat wall as the lower portion of an overhead structure such as a pavilion, gazebo or pergola. In the picture below the cedar posts are integrated into the seat wall build.  They support a cedar shake roof.
• Safety and Containment: If you have a raised patio or terrace, a seat wall around the perimeter can keep people contained and away from the dangerous edge. Make sure you check with the local construction office for building code that might pertain.  Sometimes an additional railing is required depending on code and circumstance.

Here are a few additional ideas to keep in mind.

At the end and at various intervals along the seat wall you can integrate piers.  These piers can help identify entrance points or visually break up the wall line.  Sometimes lighting is installed on the piers.

Decorative planters can also add a nice touch.  They too can be placed to distinguish an entrance or used as an occasional accent.

Capstones are somewhat of an independent element to the seat wall. Consider different capstones as another creative option in designing your wall.  I’ve even used natural stone such as bluestone and limestone to cap precast modular walls.

Construction Matters

You’ll hear the term dry-stack stone wall used. It’s basically a term that means the general construction of the wall does not happen on a concrete footing, but rather on a compacted gravel footing.

The stones are stacked on one another essentially using their position and gravity to lock them in place.  It’s not uncommon to use some mortar to “shim” and set some of the stones, especially the capstone.  Ideally the mortar does not show.

A masonry wall will have a legitimate concrete footing. Whatever material is used to build the wall on that footing (block, brick, stone, etc.) will use mortar to hold the pieces together.

A wall that includes any kind of veneer or stucco must be built on a concrete footing. If not the veneer and stucco can potentially crack and crumble.

Determine early on if lighting, audio or other utilities are part of the design.  If so, the conduits and wiring can be installed within the wall construction.

Drainage should be another consideration. Water and poor drainage can be problematic for construction.

For the structure itself you may want to install a perforated pipe and gravel as part of the base.  Water should never be allowed to collect at the base of the seat wall.

Grading is certainly another part of the drainage solution.  Always try to grade the surrounding areas so that runoff water moves away from the wall.

This is a general overview of seat walls.  There are numerous factors and circumstances that can affect the specific choices and build strategies. As always, check with the local building department to see if a permit is required and what the current wall building codes are.

Let’s take another visit to the lake home and landscape project by East Coast Landscape.  In the last post we traveled down natural stone steps alongside a well-built and engineered waterfeature.

We’re now almost to the shoreline and standing on a wide path covered in woodchips.  This path actually travels a roundabout and gradual climb up to the main house.  It serves as both an alternate route for a casual (and longer) stroll, and also provides access for smaller equipment to get closer to the lake.

Combining Natural and Man-Made Elements

It is at this point where the cascading water coming down the rocky slope meets with a natural stream.

Alan Goodell from East Coast Landscape explains how this convergence of the two water features was handled.  At the base of the slope a retention pond was built using more boulders to echo the existing rockery.  Both the natural stream and the constructed waterfall enter into this pond.

While looking like just another natural occurring feature, this engineered pond allows the two water sources to be “managed” properly.  A weir is built below one of the bridges as part of the water management system.  The water flow and level of the pond can be adjusted as needed.

On the other side of the bridge the water exits after flowing over the pond weir.  This last part of the journey for the water before entering the lake is another display of cascades over rockery.

Notice how the plantings between the stone helps to unite the boulder groupings and then visually ties everything in to the surroundings.  I actually had to look closely to distinguish between the natural and man-made parts of the project.

The Beach And Dock Area

From the wood chip path there’s only a short stretch to the lake.  East Coast constructed a wide belgian block ramp that leads to the open-front pavilion.

The belgian block cobble provides a stable, strong surface.  It naturally has a nubby texture for traction and sure-footing.  Belgian block, as a dimensional, thick, heavy paver can conform to the subtleties of the slope.   Also, its gray tones blend well with the surroundings.  I like the way the belgian block pavers combine to meet the flagstone in front of the pavilion.  Different paving elements that connect can be challenging in design.

The pavilion has an open-front and together with the flagstone patio offers a spacious room for all sorts of activities. From the pavilion there are several stone slab-steps to the beach and dock area.

The trek from the house down to the lake was certainly not an effort.  In fact, I wish it had continued!

In design, if you can bring people to a point where they are no longer thinking about the clock and perhaps what else they should be doing, you’ve created something special.

On a project like this it is an appreciation and respect for the surroundings.  The natural conditions are simply too powerful to try and manipulate them in any other way than how they naturally want to be.

Dry Laid Stonework Is Great If Built Correctly

She already knew quite a bit about the comparative features of each. She liked the fact that dry-laid stonework can “move” with nature making it less susceptible to cracking. She also saw the advantage of being able to lift and reset the dry laid stones or pavers if necessary. This feature in itself is valuable, especially around pools where you never know when you might have to dig to repair an underground water line.

“Her one concern was the issue of the patio stones “heaving.” This is where some of the stones get pushed or lifted out of their level setting and protrude above the rest. As you might suspect this not only looks terrible, but also poses quite a hazard.”