Talk about a time-consuming job that simply has to be done. Filling in the gaps between pavers, flagstones, or even stepping stones takes time, effort, and patience. Add to that, how often you plan on doing this might make the task seem daunting.

You have a few choices when it comes to filling large gaps between patio pavers. You can either use regular sand, or what is called “fill sand.”  You can apply this using a trowel, the same one you would use to spread out sand or mortar. And if that isn’t your thing, then you can just use cinder fill, which comes in a bag and is usually sold right next to the regular sand at any home improvement center.

Of course, there are pros and cons of each material. For example, filling with regular sand only works if the gap is small enough for it to pack down tightly inside.

Fill sand on the other hand has gravel inside of it, making it harden fast when mixed with concrete glue. Cinder fill is lightweight but might not be as strong as fill-sand.  

Fill sand has been specifically created so it can withstand not being watered for a lengthy period of time.

Both sands have pros and cons though. Regular sand will cost less upfront, but depending on how large your gaps are, you may need to buy more over time.

Fill sand on the other hand can be pretty expensive if purchased in bulk online which defeats some of its savings from being able to hold out longer without having to water it down.

In this article, we’re going to go into more detail about filling sand and how it may be your best option for filling large gaps in your patio.

Doing this will effectively help maintain a healthy patio or driveway and also help prevent flooding.

How Do You Fill Large Gaps in Between Patio Slabs?

You can fill large gaps in between patio pavers by using “fill sand” or polymeric sand It has been specifically created so it can withstand not being watered for a lengthy period of time.

How do you mix fill sand?

First, ensure you have a sunny day so the sand has time to dry.

Second, remove any loose debris from between the gaps.  

Third, level the gaps so it is one surface instead of two uneven surfaces which will cause problems when applying concrete glue to hold everything together securely. You need an even base for this job.   

Fourth, mix your concrete glue and water in a bucket using a trowel until completely combined without any clumps remaining.

It should be thin enough that it will flow into any small cracks but thick enough that it doesn’t drip down into other areas you don’t want it to go (like where you filled in with dirt).

Fifth, repeat step four several times until the entire area is covered with at least 1/4 inch of the mixture.   

Sixth, use your trowel or shovel to dump sand into any open areas that need filling in.

Work the sand into the gaps by shaking it back and forth with one hand while you use your other hand to apply more glue/water mix on top of the sand using your trowel.

Shake back and forth until there is no longer any sticky residue from where you applied concrete glue to hold everything together tightly.   

Seventh, allow at least 24 hours for it to dry before walking, driving, or even parking a car over the top because this can cause shifting.

Some people opt for buying polymeric sand which has been designed so it hardens when mixed with concrete but doesn’t have gravel inside it.

It’s a little more money, but you don’t have to worry about it being too lightweight and shifting if traffic is going over the top of it frequently.

If you’re interested in this, you might also be interested in How To Get Rid Of Weeds Between Your Block Paving.

What does fill sand consist of?

Typically, it consists of washed sharp sand and/or limestone screenings. Both materials are naturally occurring from the earth, making them a sustainable choice when filling gaps in your patio or even your yard.

The limestone screenings help give stability while also adding color contrast to make everything pop more. Sharp sand, on the other hand, is pretty self-explanatory. It adds some grit and texture to how dry and firm everything will settle into place over time.

How Big a Gap Can Filler Sand Fill?

Fill sand can pack tightly into a gap between large paver stones or bricks between 1/4 inch and 1.5 inches wide, especially if it is on a level surface.

It will hold its shape for the most part unless you have an extremely large area to apply it to. In some cases, sand might shift around on top of wet concrete but this doesn’t happen with fill sand because it has been specifically created to withstand being watered down while still having enough grit and texture that it won’t scatter everywhere either.

How Long Does It Take Fill Sand To Set?

Once mixed with a bit of water, fill sand will start setting within 30 minutes depending on how much moisture there is in the air at any given time. Typically, you want the humidity levels to be

How Long Does it Take For The Sand To Set?

The length of time it takes for polymeric sands to dry depends on the weather. Polymeric sands will typically be set up in 24 to 72 hours if it’s hot and sunny.

The most important aspect of setting sand is the watering ironically. The hotter the sun is, the faster everything will dry if it’s watered correctly.

The risk of watering too much is that it will saturate the sand which could lead to long-term problems when trying to wash away dirt with a hose in years down the road.

Watering too little will risk not allowing polymeric sands to dry in time before you’re able to use your driveway or patio again so keep an eye on how much moisture there is when everything has been applied.

How Long Will It Last?

Typically, polymeric sands have a lifespan of 10 to 15 years before they start shifting around excessively because the moisture has caused them to wear down over time.

If there are pieces that have worn away or scattered, you can always go back and reapply to fill sand by using your trowel to shovel it into the area, watering it down thoroughly, and allowing everything to dry before walking over the top of it.

Can You Put Dry Cement Between Pavers?

Yes, dry grouting is the technique of filling cracks in paving with a dry mix of sand and cement, then relying on natural moisture to hydrate the cement.

As you can imagine, this is a bit of a risky solution because the timing has to be just right for everything to be set up properly.

First, you’ll want to rub down any sealer that might have been applied previously so it doesn’t interfere with the dry grouting process.

Second, use your trowel and apply an amount of dry grouting into the crack that is wide enough to fill it.

Next, use your trowel again to work it into the crack until everything is flush with the surrounding surface.

Finally, you’ll want to allow everything 5-7 days to dry before applying any weight or pressure on top of the sand which could cause it to sink down into the crack again.

What Is The Difference Between Jointing Sand & Polymeric Sand?

The difference between jointing sand and polymeric sands is that jointing sands are typically used to adhere things together whereas polymeric sands are designed not to.

They both have the same texture, but jointing sands tend to be a little bit lighter so it can fluff up easier depending on its moisture level at the time.

Should You Fill Concrete Expansion Joints?

Yes, you should! Concrete expansion joints help to give room for concrete to expand and contract as it dries, contracts, freezes, and thaws.

This is more so the case with stonework than anything else because of how porous it can sometimes be.

However, you should mix both together as a way to cover all your bases for all potential future issues that could come up with your patio or driveway.

What type of sand should you use?

Typically, you want to use washed sharp sand for filling gaps in between stone slabs because it provides the smoothest finish over time.

It also gives additional stability by giving you something else to pack everything down into tightly so your patio or driveway doesn’t shift around while you’re standing on top of it.

Generally, washed sharp sand should have very few fine bits because this type of sand has the potential to become slippery over time which could lead to accidents if it builds up too much.

The best way to use sharp sand is by adding some water so everything packs down tightly and stays in place for the long term.

Filler Material For Large Gaps On A Patio With A Concrete Surface 

You can use Maxrete Post Mix Concrete, Norcros Rock Tite Mortar or Bostik 30812809 Cementone Rapid Setting Cement, for Interior & Exterior Use as a filler for large gaps on a patio with a concrete surface.

Filler Material For Large Gaps On A Patio With A Brick Surface

You can use Everbuild Ready Mixed Deep Gap Filler, Rapidcas Cement or Epoxyset NF Grey 3kg ( Formerly known as Febox NF) as a filler for large gaps on a patio with a brick surface.

Filler Material For Large Gaps On A Patio With An Asphalt Surface

You can use Geo Fix All Weather, GeoFix Paving Joint Compound, or PRO-410™ Paving Sealer as a filler for large gaps on a patio with an asphalt surface.

How to Fill Gaps in Crazy Paving

You can use jointing compound to fill gaps in crazy paving. You’ll mix it up with water and then pack everything into the gaps with your hands or a tamper.

After that, you just allow the compound to dry before walking on top of it again.

There are a few jointing compounds to use such as Maxrete Post Mix Concrete, Bostik Patio Grout, Easy To Use, Alternative to Traditional Cement, For Filling and Sealing Joints, and Sika Fastfix Self-setting Paving Jointing Compound.

Maintenance and Care for Your New Patio Filler

The key to maintaining a new patio is to keep it clean by regularly sweeping away any debris. Rinse off with a water hose, then apply a simple dish soap solution (dish soap and water) to wipe away any dirt or stains that may occur. Then apply more patio sealer as and when needed.

Places to Get Patio Filler

The good news is, there are plenty of places where you can get patio filler.

The bottom line is that there are plenty of ways to fill gaps on your patio.

You should always use the best filler that you can afford to use because it will save you money in the long run if you don’t have to keep doing things over and over again while trying to get things right.

It’s worth pointing out, though, that filling gaps on a patio with jointing sand is your very cheapest alternative.

And, you can easily use it as a temporary fix until you get around to doing things properly with regards to filling gaps on your patio.


So there you have it… a few recommendations about the best type of sand to use for filling gaps in the patio!

I hope this has been helpful!

picture of a patio in the sun.
How To Fill Large Gaps In My Patio (Best Mix)
About the Author

Passionate about helping households transition to sustainable energy with helpful information and resources.

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