Filler Options for Flagstone Patio

  • Sand: Sand is the most common joint filler, but it is challenging to keep in place and needs to be refilled.
  • Rocks: You can use small rocks to fill large gaps, and gravel or crushed rock can be used to fill smaller gaps.

How do you fill gaps between flagstones?


Quote from Youtube video: Areas like municipal parks perk grout is permeable. And easily cleaned sometimes perc grout can be stronger than the stone. Itself. It is straightforward to install.

What is the best material to put between flagstone?

Here are five types of materials to use when filling gaps between flagstones:

  • Sand. Though a very common filler, bear in mind that if you use sand for flagstone patio filler you will need to refill it from time to time as the sand will erode.
  • Rocks. …
  • Mulch. …
  • Plants. …
  • Polymeric stone dust.


What can I use instead of polymeric sand?

Builder’s Sand



Builder’s sand is the most common replacement for polymeric sand, as it is easy to access and not expensive. It is used heavily in construction projects, hence its name. Because this sand is very coarse, you will need to use it regularly. You’ll have to reapply it for years as it settles.

What do you use to grout flagstone?

How to Grout Flagstone

  1. Remove existing mortar that’s cracked or loose. …
  2. Sweep and clean the floor to remove loose stones, dirt and debris.
  3. Mix 3 parts sand to one part portland cement. …
  4. Fill a grout bag with your sand and Portland cement mixture.
  5. Insert the nozzle of the grout bag into the gaps between your flagstones.

Can I use polymeric sand with flagstone?

Polymeric sand, or “poly-sand” seemed great at first. As easy to install as regular sand, almost. You simply sweep the material into the flagstone (or other paver) joints, lightly hose down, then it solidifies. Once it dries and hardens, the sand stays in place.

What kind of mortar do you use for flagstone?

Thinset Mortar



It is a combination of sand, cement and polymers. You can trowel it on using a notched trowel with a size that is dependent on the size of the flagstone with which you are working.

How do you fill a joint in a flagstone patio?

Sand: Sand is the most common joint filler, but it is challenging to keep in place and needs to be refilled. Rocks: You can use small rocks to fill large gaps, and gravel or crushed rock can be used to fill smaller gaps. Mulch: Bark and lightweight chunks of mulch are a great option for in-between flagstone.

How do you Regrout a flagstone patio?

Quote from the video:
Quote from Youtube video: And I stick the cap down this stuff lasts forever. So now you take this I want you to run a bead. About an inch away and just go back and forth over the whole area.

How do you fill gaps in patio stones?

Quote from the video:
Quote from Youtube video: So I take some of the water a little bit it's fairly dry remember. Get it into the gap. And then I'll get my little tool. And just pack it down in nice and tight. So it's as strong as possible.

Can I use mortar as grout for flagstone?

Mortar is a type of concrete made from cement, water, sand, and usually hydrated lime. It’s meant especially for setting masonry and is sticky, so as to bind the masonry together. When considering a flagstone walkway, two basic options are available as far as grouting: mortar or a dry laid method.

How do you repair a cracked flagstone patio?

DIY Fix for Loose Flagstone

  1. Step 1: Remove the Loose Flagstone. Pull up the loose stones with a pry bar if they don’t easily come free without tools.
  2. Step 2: Remove Dirt and Mortar. …
  3. Step 3: Apply Masonry Adhesive. …
  4. Step 4: Apply Joint-Repair Adhesive. …
  5. Step 5: Set the Flagstone. …
  6. Step 6: Finish Using the Joint-Repair Adhesive.


What is Rompox?

ROMPOX® – PATIO is a 1-component special resin pavement jointing mortar that hardens/cures with air/oxygen after application. It was especially developed for the jointing of sensitive surfaces and coated concrete stone slabs.

How do I apply Rompox?

Application: Open the lid of the bucket and open the vacuum bag inside. Pour the pavement fixing mortar immediately onto the surface and using a coarse street broom or squeegee spread it evenly so that it goes into the joints deeply, firmly and compactly.

Is Rompox any good?

5.0 out of 5 starsFantastic customer service. Great product, easy to apply. I used Rompox Easy on my patio pavers (Belgard Mega Libre that look like flagsones once the cracks are filled, but which have many 1/2 inch deep “false” cracks) to replace the generic polymeric sand that kept breaking up.