Dealing With Drainage On A Stone Patio

One way to address drainage concerns in a stone patio

One way to address drainage concerns in a stone patio


Usually it is fairly easy to ensure a stone patio drains properly. Pitch it away from the house- making sure that sub grade drains away from the house as well, and the job is done. But sometimes the patio area is captured by garden beds, sloping yards and other land forms that make it hard to get water away from the home. I have used this drain design a handful of times to provide water with a path away from the patio.
The cobblestone/trench drainage system works off water’s tendency to follow a surface. The cobbles provide rainwater runoff with numerous opportunities to flow down into the pipe below and out into the yard.
A couple of things that help to keep the system working properly.
Make sure you have a reasonable amount of slope in the pipe. Two percent works well.
Keep the drainage material (gravel and pipe) free of debris and soil. Water needs to percolate through. That’s why you wrap it in filter fabric and put a sock on the pipe. Use a good grade of filter fabric. The plasticy stuff big box hardware stores sell for under mulch beds is not up to the job.
Use white PVC pipe, not the thin-wall, cheapo, black corrugated pipe contractors favor. It’s crap.
Put the holes in the perforated pipe down. The trench fills with water from the bottom up. As soon as it reaches the height of the holes, it starts to drain into the pipe and flow out.
Keep the daylight exit clear.

A cobblestone detail that covers a trench drain in a dry laid stone patio

A cobblestone detail that covers a trench drain in a dry laid stone patio

Here’s a cobblestone system installed. Done right, it can provide an intriguing visual design element to a patio. This particular system begins and ends with grinding wheels. In this case the patio and cobble stones are sandstone from Tennessee. Cobbles are not necessary, though they do provide increased opportunities for the water to perc into the drain system.

I have installed similar systems at the edge of patios where grass or mulch beds have created puddles or soggy soil. The one pictured is in the center of a patio that is stuck between the house and a steady rising slope.

A grinding wheel starts a cobblestone trench drain.

A grinding wheel starts a cobblestone trench drain.

Stone Path on a Gradual Grade

In the mountains of western North Carolina, where Hammerhead Stoneworks is located, we often deal with awkward slopes. Gradual grades, like the one pictured here, are common. The best solution usually involves striking a balance of steps and landings. This walkway features several small stacks of slab steps with flagstone landings spaced throughout. It’s important to take the rhythm of walking into account. The rise and run of steps are an agreement between the builder and everyone who uses their steps. It should be predictable and within a ratio that we are familiar with. Stuttering steps- those awkward ones that are too short or too close together or weirdly spaced- drive my crazy. (A common thing here is the two inch step at the top of a run of stairs. WHY?!)
Of course, there are other variables as well. You want to steps to fall naturally into place along the slope. If your steps are too far ahead, then you have to do a lot building up with retaining walls to support the steps. Likewise, if you get too far into the slope, there’s a lot of digging needed and you may have to install some sort of edging to keep the soil and mulch off the path. Sometimes this can’t be avoided, but often, by taking the time to pay attention to those details in the design phase, you can have a stone path that has a natural rhythm, is safe and easy to walk and is strong and durable. Like this one in the pictures!

Stone path and steps

Drystone pathway with steps. Balancing bench in the background.

stone pathway and steps

A view of the stone path and the mountains

stone pathway

Tennessee sandstone pathway with steps slabs and site boulders

Sunflower Mosaic for Frankie

Frankie on her sunflower mosaic patio

Frankie on her sunflower mosaic patio

This mosaic patio was created for my friend Carmen. She needed something to cover the muddy space just outside the doggy door that leads off her porch. Frankie, the puppy in the picture, is an enthusiastic digger and was tracking in altogether too much mud. I had wanted to try a sunflower design in stone and this seemed like a good opportunity.
Sunflower mosaic made of natural stone

Sunflower mosaic made of natural stone

The seeds are Mexican beach pebbles anchored in concrete. I cast that piece in an retired plastic flower pot. The rest of the stone is laid dry on a bed of crushed stone and sand. The background is Pennsylvania stone and the flower petals are sandstone from Tennessee. I might simplify the design if I were to revisit it. There’s a slight “S” curve on the petals that required more time for cutting and shaping than a straighter line might have, though if it were bigger, that curve would be easier to cut.

North Asheville Stone Patio and Steps

dry stone wall and steps

A drystone retaining wall supports a set of carefully stacked steps. This is an overview of a recent Hammerhead Stoneworks project in North Asheville.

This is a recent Hammerhead project, a patio and wall combination to create a exterior space at a home in North Asheville. We used sandstone from Tennessee, one of our favorite stones for tight walls and flat floors.

A favorite detail of this project is the set of steps that emerge from the face of the wall. It’s all dry laid- no concrete or mortar. The design offsets two walls, providing support for the steps. This creates the effect of a single wall that is pulled apart to reveal the steps. I love the look and like how sturdy they are.

stone step emerge from dry laid wall

This is a close up of how the steps emerge from the dry stone wall. Super sturdy, clean lines- how Hammerhead rolls…

Dry stone wall detail

Detail of a section of drystone wall built by Jonathan. Part of a patio/wall project in North Asheville.

Stone cut for downspout.

Detail showing where the downspout plunges through the patio surface. There’s a marble we found on site tucked on the right side there.

Black Mountain Patio

We just finished transforming this Black Mountain backyard from a ragged old deck with drainage issues into a dynamic living space with a fire table. Over the course of the last year we have been using larger and larger slabs of flagstone, but keeping our very tight tolerances for the joints. The results are more like a floor in terms of level and walking comfort than the typical concept of a patio, which is often as much filler as stone. All of the work here is drystone, except for the fire table, which has some refractory mortar in the fire brick for stability. I’ll post about that when I have some good images of it in use.

Getting started on a large patio.

Getting started on transforming this backyard in Black Mountain.

Big flagstones in a patio in Black Mountain, North Carolina.

A panorama from above the Black Mountain patio, from above

Black Mountain patio completed

We transformed this Black Mountain backyard with a patio and fire pit. Many of the flagstones are huge and all the work is laid dry.

A large patio is supported by a tightly fitted retaining wall.

This crib wall supports a large patio in Black Mountain.

Pebble mounted into a larger stone.

A pebble mounted into the face of a small boulder.

Weaverville Nature Park Stonework

Drystone wall and path in Weaverville.

We built this wall and sidewalk in Weaverville at the Downtown Nature Park.

Hammerhead Stoneworks recently completed this wall and sidewalk for the Town of Weaverville’s Downtown Nature Park. My boys and I take frequent walks there looking for bugs and snakes and tree frogs, so this was an exciting opportunity to make public work that I’ll get to enjoy.

The wall is a two sided, free-standing structure. Except for the seating cap, which is mortared in place, the wall is all drystone. It’s a very labor intensive approach to building a retaining wall, but I know well how kids will run and jump and scramble along the wall. We wanted to make the most durable and sturdiest product we could. I think it’s pretty too.

Drystone wall and path in Weaverville, North Carolina.

We built this wall and sidewalk in Weaverville at the Downtown Nature Park.

Drystone wall and path in Weaverville, North Carolina.

Drystone wall and path in Weaverville, North Carolina.

The pathway is also laid dry, over crushed stone. We used very large pieces, to give visual impact and to make the surface very, very stable. We used a wide variety of stone types, to give it different colors, patterns and textures. All the stone is sedimentary, which generally makes good walking surfaces.

Van accessible parking area with a drystone sidewalk.

The stone sidewalk fades down to the same level as the asphalt, creating an accessible parking area at the Downtown Nature Park in Weaverville, North Carolina.

The stone sidewalk fades down to the same level as the asphalt, creating an accessible parking area at one end of the new parking area. I like the abstract shape formed by the stone against the asphalt. That last section is a parking area for a van that can just pull up parallel to the stone sidewalk.

Seating wall

Stone sitting wall built in Weaverville by Hammerhead Stoneworks.

Stone Sidewalk

Process shot of a stone sidewalk being installed in Weaverville, North Carolina.

Process shot of a stone sidewalk being installed in Weaverville, North Carolina.

The crew has been working diligently on this stone sidewalk at the Main Street Nature Park in Weaverville, North Carolina. The sidewalk is five feet wide and has a two percent grade from the wall to the parking area, which will someday be paved with asphalt. The stone is almost all sandstone from Tennessee, sometimes referred to Crab Orchard. I like the mixture of colors and textures.

Stone River Step

Stone step with large landing

A river of bluestone runs through a step and landing.

This is the top step and landing that leads into a home in Fairview. The river is cut from Pennsylvania bluestone and runs through a field of Tennessee sandstone. We cut steps slabs in half lengthwise to create the edges to support the flagstone landings.
Steps and landings that lead into a Fariview home.

A bluestone river runs through a set of steps and landings.

Flagstone Patio Panorama

patio and bench wall panorama

Panorama of sitting walls and flagstone patio.

This panorama shows a flagstone patio and a seating wall we built last winter. The wall has a curve that has been flattened by making the panorama. The seating wall is drystone, with a mortared cap.
Click the image for a closer look.

Stone Steps with River Design

steps design sketch

Soapstone rendering on sandstone of stepstones. Words to that effect.

We’re working in Fairview right now, building a small flagstone patio adjacent to the house and replacing some tired timber steps that lead to the front entrance. The front steps will have a design that flows through them, meant to resemble water. The first pieces are in place. The sketch is on one of the sandstone slabs that will make the landings. We use soapstone to make our mark.
stone steps with flagstone landings

Starting a set of steps with flagstone landings. A river will run through it.