NATURAL STONE/FLAGSTONE: A BEAUTIFUL ALTERNATIVE TO CONCRETE PAVERS

HOW TO INSTALL – NATURAL/FLAGSTONE
(different thickness stones)

Natural stone is a beautiful addition and home improvement project. Travertine is a popular stone type for both interior and exterior uses. But one consideration to keep in mind is that travertine is softer than some other natural stone products. This may be an issue if you are using Travertine for your patio, where the movement of patio furniture may scratch or chip the tiles. But don’t think of it as “soft”, after all it’s still stone. In fact, it has been used on the exteriors of buildings dating back to Roman times – it just may be more likely to scratch or chip than other natural stone types.

Other common stone types are flagstone patios and walkways, slate, granite and even limestone. The main challenge is to get the natural stone level, and then to keep it level for years. Using Brock PaverBase below your natural stone gives it a stable platform to prevent stone settling. Using Brock PaverBase under natural stone is slightly different than using it under pavers, which are more regular in thickness and fit. So how to build your patio with Brock PaverBase depends on the stone style you chose.

Step 1 PREPARING THE AREA FOR YOUR PATIO DESIGN

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Most commonly this is removing a grass area that is around your current concrete patio. You will incorporate this area into your new larger outdoor patio design. You will need to excavate about 1” deep from the surface of your current concrete slab for the area of your extended patio.

REMOVAL GUIDE

Step 2 HOW TO BUILD A STONE PATIO

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First create a level and solid base.
Any surface should slope away from structure.

If you are building a patio close to or attached to the house, use a hard rake and/or shovel to level the area and make sure it slopes away from any structures. The base material (most commonly the ground) should be tightly compacted using a hand tamper or plate compactor. The slope of a patio should be about 1/4″ per one foot of distance in order to let water flow off the surface but keep furniture stable and level. It is helpful to pull a string line so you can check your slope.

To run a string line, put two landscape stakes in the ground. Tie a piece of string to one of them, and then pull it tight to the other. Use a level and ruler to create the desired slope. For example, the patio should slope 2.5″ over a 10 foot distance (Diagram below). This will ensure that rainfall flows off the patio.

The area should be properly compacted. The area should be as smooth as possible, making sure to get rid of high and low spots to within +/- 1/4″. This is now your compacted base. Congratulations, the hard part is over!

STRING LINE SLOPE GUIDE

Step 3 ADD A WEED BARRIER FABRIC

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Add a weed barrier fabric on top of the compacted base. Make sure to leave an extra 10” in all directions for later.

WEED BARRIER FABRIC
WEED BARRIER FABRIC

Step 4 SPREAD A THIN LAYER OF SAND

Spread an even layer of sand to a depth of 1/2″ – 1″ deep on top of the leveled and compacted base. Use the sand to get the surface as smooth as possible.

1/2" LEVELING SAND
1/2″ LEVELING SAND

Step 5 LEVEL THE SAND USING A BOARD

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Screed the sand using a straight board. A standard 2×4, about 6′ long works well. Make sure it is straight and true! The board will also help you keep the slope so watch your string line.

1/2" LEVELING SAND SCREED
1/2″ LEVELING SAND SCREED

Step 6 INSTALL BROCK PAVERBASE PANELS

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Starting against a straight edge of the patio, lay the Brock panels, ensuring that the side flanges overlap. Ideally, lay them in a “brick-like” pattern (illustration below). This will ensure stability of the panels when you lay the pavers.

Trim any curves or along edges using a razor knife. Place any extra scrap pieces of Brock PaverBase in your recycling bin.


Step 7 ADD A SECOND LAYER OF WEED BARRIER FABRIC

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Once the Brock PaverBase is installed, place a second layer of weed barrier fabric on top of the panels to stop any sand migration. Be sure to leave it 4-5” long in all directions.

WEED BARRIER FABRIC
WEED BARRIER FABRIC

Step 8 SPREAD A THICK LAYER OF BEDDING SAND

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Then add a .5” thick layer of bedding sand on top of the fabric. This is the layer of sand that will make up any differences in thickness that your stones may have, and allow you to get the stones to sit level, as they may not be perfectly flat on the bottom.

BEDDING SAND
BEDDING SAND

Step 9 INSTALL THE NATURAL STONE

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This is the fun part! Laying natural stone is very simple. Before putting the stone onto the project lay them out in the yard and try to find the pieces that fit well together with the size joint you like. There is a slight art to figuring out which stone fits best where, but that is what makes no two patios the same. Once you have an idea of where you want them. Take the ends of the geotextile that you let long and simply fold them over on top of the sand to make the whole system sealed so you are sure nothing will move. Then install the stones into the bedding sand. If you find an area with a stone that is very thin and there is not enough bedding sand, simply add more underneath it until it is level and positioned where you want it. The same holds true for a stone that is slightly to thick. Simply brush some of the sand away until it lays as you want it. Try to keep the bedding sand on the bottom of the stones and don’t let it work to far up between them as we will be filling the joints with a special sand later to hold it all together. Make sure to leave 2-3” of exposed sand around the outside of your project to later add edge restraint.

NATURAL STONES
NATURAL STONES
Install edge restraint.

Once your stones are installed it is important to hold the perimeter of your project in place. Simply place edge restraint on top of the sand and the geotextile fabric that we folded over earlier. Then install using 8-10” landscape spikes. You may feel free to bend the edge restraint to follow the natural outline of the stones to give your patio a more natural feeling.

EDGE RESTRAINTS
EDGE RESTRAINTS

Step 10 FINISH WITH REGULAR OR POLYMERIC JOINT SAND

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Using a broom, spread sand over the patio and into the gaps between the pavers. Spread over small areas before moving onto the next one. Go back and forth over the gaps until no more sand will fit.

Note:

Polymeric sand will essentially harden like concrete between your pavers. It has several advantages: It is stable, so the sand won’t end up on the top of your pavers; It allows you to power wash your patio without displacing the joint sand; It gives the patio a cleaner, more finished look. Be sure to use a Polymeric sand or even a sandy soil that will allow you to plant ground cover between the stones that is rated for the widest joint on your project. An alternative is traditional joint sand.

POLYMERIC SAND
POLYMERIC SAND

Step 11 CLEAN THE SURFACE OF THE NATURAL STONE

Once you are done spreading the polymeric sand into the gaps, use a leaf blower to blow the fine dust off the surface of your patio. (You want to make sure you sweep it off well first or you will generate a large dust cloud!).

Note:

DO NOT WASH IT OFF WITH WATER! THAT COMES LATER. If the natural stone is not free of polymeric sand on the surface, you may see a film/haze on the stones once you follow step the next step.

Proper wetting when using polymeric sand.

Once the surface of the patio is completely clean, follow the instructions for wetting on the packaging of the polymeric sand. This will entail lightly spraying the joint sand with water, which will activate the polymer that hardens the sand.