Why Your Patio Needs the Right Bedding Sand
Table of Contents
Why Does a Patio That Looks Perfect on Day One Start to Dip, Spread, or Grow Weeds a Few Months Later?
Often, it comes down to the sand you cannot see. Sand for pavers is not one material doing one job. Bedding sand supports and levels the pavers from below, while jointing sand locks the surface together from above. You need the right sand in the right place, because the wrong choice can turn a clean patio, walkway, or driveway into a costly repair.
Central Home Supply helps homeowners and contractors choose materials that fit the job before the first paver goes down. From our Santa Cruz and Scotts Valley yards, our team can walk you through bedding sand, jointing sand, and the tools needed to build a surface that stays level, drains properly, and holds up to everyday use.
Which sand do you need?
| Sand Type | Where It Goes | Best For |
|---|---|---|
| Coarse bedding sand (sharp sand) | Under pavers, 1-inch layer | Leveling and drainage |
| Regular loose jointing sand | Between pavers | Low-budget, temporary fills |
| Polymeric jointing sand | Between pavers | Weed resistance, durability |
| Resin-based jointing sand | Between pavers | High-traffic, freeze-thaw climates |
Here’s the problem most homeowners run into: they finish laying a beautiful patio, fill the joints with whatever sand was left over from the base, and then watch weeds push through and sand wash away with the first heavy rain. Before long, the pavers are shifting, the joints look ragged, and the whole surface needs to be redone.
It doesn’t have to go that way. The right sand in the right place keeps pavers locked, level, and low-maintenance for years.
I’m Reed Santee, owner of Central Home Supply. After decades of supplying materials to homeowners and contractors across Santa Cruz County, I’ve seen how the right material choice makes the difference between a patio that lasts and one that doesn’t. This guide covers everything you need to choose, calculate, and apply the right sand for your project.
What Is the Best Sand for Pavers: Bedding Sand or Jointing Sand?
When planning your dream outdoor space, it is easy to get swept up in selecting the perfect Pavers and overlook the humblest component of the project: the sand. However, the sand you choose acts as both the cushion and the lock for your entire hardscape.
According to the Interlocking Concrete Pavement Institute (ICPI) guidelines, your patio relies on two distinct layers of sand, each with its own physical requirements. Bedding sand must meet ASTM C33 specifications (coarse, washed concrete sand), while jointing sand is much finer to sweep easily into tight gaps.
One of the non-negotiable rules of hardscaping is the 1-inch bedding depth standard. If your bedding layer is too thick (over 1 inch), the sand will displace under foot and vehicular traffic, causing your pavers to sink unevenly. If it is too thin, the pavers will rock against the hard gravel base beneath them, leading to chipped edges.
| Feature | Bedding Sand (ASTM C33) | Jointing Sand (ASTM C144 / Polymeric) |
|---|---|---|
| Primary Location | Beneath the pavers | Inside the gaps between pavers |
| Texture | Coarse, sharp, and angular | Fine, smooth, or polymer-blended |
| Key Function | Creates a flat leveling cushion | Locks pavers together, blocks weeds |
| Washout Risk | Low (trapped under pavers) | High (if using regular loose sand) |
Understanding the Role of Bedding Sand and Jointing
Why can’t you just use any cheap sand for the base? The secret lies in the shape of the sand grains.
Bedding sand must be “sharp” sand with angular grains. When compacted, these jagged edges lock together like microscopic puzzle pieces. This interlocking action prevents the sand from shifting sideways when heavy loads roll over the surface. Rounded sand grains, like play sand or beach sand, act like tiny ball bearings instead, causing your pavers to shift, tilt, and sink.
For a reliable bedding layer, we recommend using a high-quality 1 Washed Sand or 2 Washed Sand. These washed options remove fine dust and clay particles, ensuring excellent drainage. If you are working on a project that does not require strict ASTM C33 specifications, a sturdy Fill Sand can sometimes be used for basic utility leveling, but sharp concrete sand remains the gold standard.
Using the right coarse base sand is also your best defense against water pooling. On the coast in San Francisco or down in Carmel Valley, damp winters can cause water to collect under poorly drained patios, leading to shifting. Angular, washed sand allows water to filter straight through into the sub-base.
Polymeric Sand vs. Regular Sand and Resin Compounds
Once your pavers are laid on their bedding course, you have to fill the joints. This is where you choose between loose jointing sand, polymeric sand, and resin compounds.
- Loose Jointing Sand: Traditional options like Quikrete 50 lb. Patio Paver Sand 115049 or Pavestone 0.5 cu. ft. Paver Sand 98000 are inexpensive and easy to sweep. However, they easily wash out during heavy rains or pressure washing and offer zero protection against weeds and ants.
- Polymeric Sand: This is a high-tech blend of graded sand and binder additives that harden when misted with water. It sharply reduces weed growth and washout compared to loose sand, which cuts how often you need to re-sand the joints. Once cured, it resists rain washout and holds up to careful pressure washing; keep the nozzle at a wide angle and stay under the pressure your sand manufacturer specifies.
- Resin-Based Jointing Sand: The ultimate heavy-duty option. Resin sands cure through air exposure rather than water activation. They are highly permeable, completely frost-resistant, and can handle extreme vehicle traffic (up to 40 tons when paired with a professional bedding system).
If you are looking for a reliable, middle-ground loose sand for tight-budget projects, Quikrete 50 lb. All-Purpose Sand 115251 or Quikrete 50 lbs. Paver Base Sand G069 can work as budget-friendly joint fillers, but they will require regular top-offs as they erode over time.
Calculating Your Sand for Your Pavers Requirements
There is nothing worse than being halfway through a weekend DIY project in Scotts Valley only to realize you are two bags short of finishing. To avoid mid-project supply runs, you need to calculate your bedding and jointing sand separately.
- Bedding Sand: To calculate your bedding sand volume, multiply your patio’s square footage by your bedding depth (which should always be exactly 1 inch, or 0.083 feet).
- Formula:
Square Footage × 0.083 = Cubic Feet of Sand Needed - Pro Tip: Divide your cubic feet by 27 to get cubic yards if you are ordering in bulk from us!
- Formula:
- Jointing Sand: Jointing sand coverage depends heavily on the size of your pavers and the width of your joints. Smaller pavers (like 4×8 bricks) have more joints per square foot than large-format slabs, meaning they require more sand. Generally, a standard 40-pound bag of polymeric sand covers approximately 40 to 100 square feet.
To make things easy, you can use our online Calculator to estimate your materials. If you want to cross-reference your math, third-party tools like the Paver Sand Calculator and Estimator or the Paver Sand Calculator are great resources. Always add a 10% waste factor to your final order to account for compaction, spills, and sweeping cleanup!
How Do You Install and Maintain Polymeric Sand?
Applying polymeric sand is a straightforward DIY task, but it requires strict attention to detail. Because the polymers react to moisture, any shortcut in the preparation or watering phase can ruin your hardwork and leave permanent stains on your pavers.
Preparing Joints and Avoiding Staining
If you are retrofitting an existing patio, you must first get rid of the old, weed-infested sand.
- Step 1: Clean out the joints. Use a pressure washer or a stiff joint brush to blast out the old sand to a depth of at least 1.5 inches.
- Step 2: Kill the weeds. Apply a non-selective herbicide to kill any remaining root systems. Let it dry completely.
- Step 3: Ensure absolute dryness. This is the most critical step. Your pavers must be 100% dry before you pour the polymeric sand. If the paver surface is even slightly damp, the polymers will activate on top of the stones, leaving a cloudy, white residue known as polymer staining.
- Step 4: Sweep and compact. Pour the sand and sweep it into the joints using a hard-bristle broom. Run a vibratory plate compactor (which you can rent from our Scotts Valley yard!) over the pavers to shake the sand down to the full depth of the joints.
- Step 5: Blow off the excess. Use a leaf blower on a low setting at a 30-degree angle to blow every speck of dust off the paver faces before watering.
For more detailed guides on laying bases and stones, check out our resource on How to Lay Stepping Stones.
Watering, Curing, and Climate Performance
Once the paver surface is completely clean, it is time to activate the sand.
Set your hose nozzle to a gentle “shower” setting. Mist the patio in sections of about 10×10 feet, watering for roughly 30 seconds per section. You want to saturate the joint sand without causing water to pool on top, which can float the polymers out and cause staining.
Polymeric sand remains flexible after curing, making it highly resilient in freeze-thaw climates. When water freezes, it expands by about 9%. Because cured polymeric sand is flexible, it stretches and yields to this expansion instead of cracking like traditional mortar. This makes it ideal for driveways and high-traffic areas.
If you are planning a heavy-use area, read our guides on 10 Reasons Install Interlocking Pavers and Driveway Pavers Types to ensure your base is strong enough to handle the load.
How Do You Maintain, Seal, and Choose Alternatives to Polymeric Sand?
To keep your paver joints looking brand new, we recommend applying a high-quality paver sealer after the polymeric sand has fully cured (usually 2 to 3 days after watering). Sealing locks in the sand and protects the paver faces from oil spills and UV fading.
Are there times when polymeric sand isn’t the best choice? Yes!
- Red Clay Bricks: Polymeric sand will stain red clay bricks no matter how careful you are. For clay bricks, traditional Type N mortar or plain jointing sand is a safer choice.
- Extremely Narrow Joints: For joints narrower than 1/16 inch, standard polymeric sand cannot settle properly. In these cases, a fine masonry sand or specialty jointing dust is required.
At Central Home Supply, we carry everything from Gravel and Sand to specialty sealers and tools. Whether you are building a gorgeous Patio with Pavers or trying to select the Best Paving Material for a new walkway, our family-owned team is here to help you get the job done right.
Stop by our yards in Santa Cruz or Scotts Valley, or contact us today. If we don’t have the exact sand or tool you need in our massive 2,500-product inventory, we will track it down for you!
