Dry Fit vs Mortar Fit Flagstone

Flagstone Patio with Brick knee wall by Capital Masonry

Dry or Mortar Set Installation?

Is a new patio part of your plans for the spring? Whether you’re building a new patio, walkway or outdoor seating area, or you want to upgrade what you have, flagstones are a durable and beautiful option that will add appeal to any landscaping. Spring is the perfect time to get going on a new addition that will add years of enjoyment to your outdoor space.

What’s Next?

Once you’ve chosen where you’d like your new patio or other hardscaping elements, you’ll need to choose the type of installation you prefer. Mortar-set installation is the most common but some people prefer what’s called dry-set installation.

What’s the Difference?

Dry-set flagstones. If you’re skipping the use of mortar, you’ll be doing what’s called a dry-set installation. For the best results, you have to first clear the ground where your patio or walkway will be. You’ll need to dig and clear a layer several inches deep. This cleared area is then filled with sand or gravel. As a final step, you place the pavers on top of the sand in your desired pattern.

Mortar-set or wet-set flagstones. For this method, you will need either a concrete slab that’s already in place, such as an existing concrete driveway, or a newly-built layer of compacted sand and gravel. The idea is to create a smooth, solid base for the installation. You mix wet mortar and apply it evenly over the base. You lay the pavers or stones on the wet mortar and allow the mortar to dry. To finish the job, you can then add mortar or grout to fill any gaps between the stones.

Which is the Right Choice?

The choice of dry-set or mortar-set will depend on your specific circumstances. You’ll need to take into account how durable you want the installation to be, how much maintenance you’ll want to do and the overall costs. Start with a look at the advantages and disadvantages of each one.

Pros of Dry-Set Application

  • Faster and easier to install.
  • When stones break or lift, repair or replacement is similarly quick and easy.
  • Some people like the loose, “unfinished” look of a dry-set patio or walkway.

Cons of Dry-Set Installation

  • More prone to buckling and heaving during freeze-and-thaw cycles.
  • If a sealant is not added sand will track into the house and yard.
  • Not as durable as wet-set installation, typically lasting about 10 years.
  • Moisture can seep under the stones, causing them to shift out of place.
  • You have to continuously replace the sand and gravel.

Benefits of Wet-Set Installation

  • The finished look is upscale and elegant.
  • Mortar-set flagstones are more durable, often lasting up to 50 years with only minor repairs needed.
  • Grout colors can be mixed to create a distinctive look.
  • Provides a more safe, secure base in high-traffic areas or around pools.
  • It’s the best choice if you’re using irregularly shaped stones or pavers.

Cons of Mortar-Set or Wet-Set Installation

  • If repairs are needed, they will require a professional mason.
  • Because it’s more labor-intensive, it can be more costly upfront.

What We Recommend

At Capital Masonry, we recommend mortar-set installation because we’ve seen the results. Mortar-set flagstone is a low-maintenance way to add a beautiful, upscale look that blends well with any landscape design. Wet-set installation is also safer for areas that get high traffic or where the stones regularly get wet.

Some people who opt for a dry-set flagstone installation end up changing it to mortar-set after discovering that it isn’t as durable, safe or as attractive as they’d hoped.

When you’re ready to get going on that new installation, call Capital Masonry. We’re a third-generation masonry with an outstanding ranking on Angie’s List, a perfect BBB rating and many satisfied customers in Virginia, Maryland, and the District. We specialize in brick, flagstone, fieldstone and concrete projects that will bring your backyard to life.