How to Lay Flagstone on Dirt – 7 Easy Steps & Tips

Flagstone is a popular natural stone and is mainly used for patios, walkways, floors, fences, and pool copings. The stone usually comes with jagged edges and rectangular or square shapes for landscaping use. It enhances the beauty of the exterior providing a solid rustic look. Because of its adaptability properties, flagstone can be laid on almost everything including dirt.

However, when you know how to lay flagstone on dirt, you will see the benefits coming through it within no time.

How to Lay Flagstone on Dirt

Compared to other natural stones or materials, this sedimentary rock has been widely chosen for paving since the 1900s. Also, flagstone is heavier and has acid-resistant properties hence laying it on the dirt surface directly is no trouble.

So, to know everything in detail about laying flagstone on the dirt be with us till the last.

What is the Best Material to Put Between Flagstones?

Many do not want weeds to be grown in between the gaps of their flagstone patio. Hence, feeling the gaps is the only solution and it is necessary as well. It resists weed growth and keeps the flagstone in position. Also, if you fill the gaps, it will increase its beauty making it low maintenance. The right filler can make your flagstone patio level, safe, and gorgeous.

Read Also: 9 Best Flagstone Sealer for Outdoor 2023


However, there are many materials that are considered as good fillers. These are used to fix and fill the gaps in the patio. The materials are given below.

#1. Sand:

Sand is probably the most common and traditional material used as a joint filler in flagstone. It comes with an easy filling process. Also, it is challenging as it is tough to keep the material in place. Hence, it requires refilling.

However, the smaller particles of the sand work better for this purpose. Flagstones that have smaller gaps in between them and much closer to each other work well with the smaller sand for filling.

#2. Polymeric sand:

Polymeric sand is a joint filler

Polymeric also known as poly-sand is a special kind of mixture of fine sand and other additives mostly polymers. With water, this polymeric sand combination works as a strong glue. The glue is potential enough to hold on to the sand particles altogether to act as a decent filler.

#3. Small Rocks:

Small Rocks joint filler

Small rocks are also used for filling the gaps between flagstones. For larger gaps, the small rocks work well. However, for smaller gaps, you can use crushed rocks or simply gravels.

#4. Plants:

Plants are joint filler

Plants are also wise fillers between flagstones. You can grow beautiful moss plants in between the flagstones. You can also grow grass to make it look more beautiful.

#5. Mulch:

Mulching is also a good option for filling in between the flagstone. Many use cocoa shell mulch to achieve an extraordinary look. However, good chunks of lightweight mulch or bark are also useful fillers.

7 Steps to Lay Flagstone on Dirt:

Coming to the main point, laying flagstone on dirt is not a tough task. Anyone without being professional can do it if he or she knows the easy steps we are going to share below. Give a minute look.

Step-1: Grab the Essential Tools and Materials:

Before starting any project, you need to have all the necessary tools the task may require near your hands. Thus, for laying flagstone you will also need some essential handy tools including,

  • Measuring tape
  • Marking paint
  • Shovel
  • Scissor
  • Hammer
  • Chisel
  • Line Level
  • Rake
  • Garden Hose
  • Broom
  • Plate Compactor

Also, you will need some important materials such as,

  • Flagstone
  • Gravel
  • Stone dust or Decomposed Material
  • Fill material as per your requirement

Step-2: Measure Your Patio:

make stone shaped rectangular

This is the first very important thing to do when you are planning to lay flagstone. There you can go either for a formal patio or for an informal patio as per your demand. A formal patio or walkway will enable you an organized look with the same sized and shaped rectangular flagstone. However, an informal patio comes with more like an organic appearance with naturally shaped stones.

Now, that you have determined the place where to settle the flagstone, you need to measure the area. Now you have to get the square footage of the patio. Hence, to get the result multiply the patio length by its width. When you calculate, the result will say how many square footage of flagstone you need for your project. According to the amount, you can order them from a landscape material supplier.

Step-3: Preparing the Dirt:

With a shovel dig down from 3 to 6 inch

This is the second-most important thing to do. With a shovel dig down from 3 to 6-inch dirt. Do it the whole area you have measured. Generally turning the dirt is the main purpose here. Do not set the dirt aside. After turning the dirt, grab the stone rake and with the tool break the dirt clumps into pieces. Discard if grass or weeds are found in the piles. Finally, rake the area level and smooth.

Step-4: Laying Pieces of Stones One by One:

Laying Pieces of stones

This is somewhat a tiresome process as not all the stones come in the same size and shape. However, in the process, the flagstones will be laid initially. According to the chosen grade, the stones will be laid flattening and the proper leveling requires patience. Puzzling the flagstones according to their sizes is a big game to play.

Hence, keep patience and do the process slowly. Nonetheless, many call for a contractor and the hired contractor does it with all his professional skills. Again, you can also do it. Lay the stones one by one into the dirt eventually shifting is side to side and back and forth.

To make sure the stones lay flat you can use a level. Now, so that the stones do not wobble or shift, pack the edges of the flagstones with soil. To check out if the placement is not wobbly stand on the stone.

Step-5: Final Placement

Now, lay the rest of the flagstones next to the initial stones. Adjust them, in the shape you want for your patio. Make sure, there are at least two finger widths between the flagstones. Use a saw or hammer for better fitting of the stones.
Check if the flagstones are properly fitted in your preferred area.

Step-6: Cleaning:

When you are done with the placement of the stones, clear off the extra dirt on the stones using a broom or a hose. Cleaning is important in this step otherwise you will be in trouble while filling the cracks in between.

Step-7: Filling with Gravel or Sand:

Filling with Gravel or Sand

Finally, fill the gaps between the flagstone with gravel or sand as per your wish. Spray water mist all over the gravels and stones to set them properly. Let them dry first and then step on them.

Tips to Keep in Mind:

Acknowledging some tips and tricks will help you to bring the best result for the job. This will surely help you with the efficient installation of the flagstone. The tips are given below.

  • Cutting the flagstone is quite challenging. It is a time-consuming process and also a bit messy and untidy as well. Hence, so that you have to make very few cuts, try to cut the pieces together.
  • Place the stones on the outside perimeter that are comparatively larger. On the other hand, place the smaller pieces of stones in the center. This technique will enable the larger stones to hold up and lock the smaller pieces in one place.
  • A power tool with a diamond blade is considered appropriate for cutting down the flagstone. However, to knock off the stone edges you can simply use a hammer though a blade will be more effective and efficient.
  • As leveling the flagstone is quite difficult, using decomposed granite will make the task easier. Decomposed granite will help the stones to sit tightly into the dirt.
  • Decomposed granite will also help in reducing the greenery or weed growth in between the cracks.
  • However, keeping bigger gaps in between is the easy solution to cut down the stone on time. However, if you want a tight and consistent patio or walkway then this idea is not for you.
  • Use the proper tool for doing the task right and accurately. Ask for expert help if needed.

What material do you put under the flagstone?

When installing flagstone, it’s important to use a suitable base or underlayment material to provide stability, prevent shifting, and promote proper drainage.

Crushed Stone or Gravel: Crushed stone or gravel is a popular choice for the base material under the flagstone. It provides good drainage and stability. You can use various sizes of crushed stone, with larger stones at the bottom and smaller ones on top for better compaction.

Sand: Sand is another option for the base material, especially for dry-laid flagstone installations. It allows for easy leveling and helps with drainage. However, it may not be the best choice in areas with heavy rainfall, as it can wash away over time.

Mortar Mix: In some cases, flagstone is set in mortar, which serves as both the base and the adhesive. Mortar provides a stable and long-lasting foundation but is typically used for wet-laid flagstone installations.

Concrete: Concrete can be used as a base for flagstone in certain situations. It provides excellent stability but may not be suitable for all projects, as it can be more challenging to work with and may not allow for water drainage.

Polymeric Sand: Polymeric sand is a mixture of sand and a polymer adhesive. It is often used to fill the joints between flagstone pieces to prevent weed growth and maintain stability.


Question: Do you need sand under flagstone?

Answer: The material you are going to use beneath the flagstone is important to know. It is one of the structural issues. Many people use gravel under it which is alright if the gravel is of the right type. Especially, road base gravels are suitable for flagstone foundations. But sand is not suitable in this case.

Getting all over the places, the sand will only dig up the stones. It may also wash away over time by wind or rain. So, simply you do not need sand under flagstone but you can use it as a filler in between the gaps.

Question: Can I lay flagstone over grass?

Answer: You can certainly lay flagstone over grass just like the way we have shown how to lay flagstone on dirt previously. First, you need to determine the spot where to place the flagstone. Measure and mark out the pathway according to your requirements.

Then, find out where the footsteps might occur by walking casually on the marked pathway. Point out the spots and for quick identification, you can spray paint on those spots. Now, dig the ground with a shovel according to the shape and size of your preferred flagstone.

Now, set the flagstone where you dug. Continue the process to cover the whole area you have selected. Nonetheless, you can use gravel while setting the flagstone for its tight placement and to fill up the steps properly. So, you can see laying flagstone over grass is as easy as laying flagstone on dirt.

Last Updated on September 25, 2023 by Rogers Weber

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