Polymeric and Paver Sand FAQs

Polymeric sand is graded jointing sand blended with water activated polymer binders. You sweep it into the joints between pavers, mist it with water, and the binder cures into a firm, slightly flexible joint. It is also sold as jointing sand, paver joint sand or poly sand. The binder is what separates it from plain masonry sand, which stays loose forever.

Paver sand is a general term that usually means plain bedding or jointing sand with no binder. Polymeric sand has polymer binders mixed in. Bedding sand goes under the pavers and should stay loose so the pavers can settle and drain. Polymeric sand goes in the joints between them and is meant to harden. Using the wrong one in the wrong place is one of the most common DIY mistakes.

No, and that is intentional. Cured polymeric sand is firm to the touch but retains slight flexibility so it can move with freeze and thaw cycles without cracking apart. Concrete or mortar in a paver joint is rigid, and on a flexible sand or gravel base it cracks within a season or two.

Techniseal, a Canadian manufacturer of paver installation and maintenance products, introduced polymeric jointing sand in 1999. Most major hardscape brands now produce their own formulations.

There are three broad families. Standard polymeric sand handles typical paver joints. Polymeric stone dust uses a coarser aggregate for wide, irregular natural stone joints. Resin and air cure jointing compounds set without the same watering step and can often be installed in wet weather. Which one you need is driven mostly by joint width and stone type.

Start with joint width, because every product is rated for a maximum. Standard sands handle up to about 1 inch. Wide joint formulas go to 2, 4 or even 6 inches for flagstone and irregular stone. After that, consider paver type, whether the surface needs to drain, and colour. Our polymeric sand calculator lists the rated joint width for every product we carry.

For most concrete paver and flagstone patios, no. The alternatives all trade something away. Plain sand washes out and grows weeds. Mortar cracks on a flexible base. Resin and air cure compounds are excellent but cost more and suit specific situations such as wet weather installs or permeable systems. Polymeric sand remains the best balance of cost, durability and ease for typical residential work.

They solve different problems. Polymeric stone dust is designed for wide, irregular joints in flagstone and natural stone where standard sand would not stay put. For uniform concrete pavers with joints under an inch, standard polymeric sand performs better and is easier to install cleanly.

Only with a formula made for porcelain. Porcelain is dense and non porous, so it does not absorb water the way concrete does, which makes standard products far more likely to leave haze on the surface. Use a porcelain specific jointing sand.

Permeable systems need a permeable jointing product so water drains through the joint rather than sitting on top. Pool decks need something rated for constant wet exposure. Both are covered in our resin and permeable jointing sand range.

It is used in Florida, but the combination of frequent heavy rain, high humidity and short dry windows makes the curing step harder to get right. Binder that gets rained on before it sets washes out. In those climates installers often prefer air cure or wet weather formulas that are effectively rain safe on install.

Most manufacturers want the sand compacted into the joint so it fills to full depth with no voids. A plate compactor with a protective mat is standard on larger jobs. On a small patio you can often achieve the same result by sweeping in stages and tapping the surface, but check the bag, because some products specifically require mechanical compaction and others specifically do not.

Yes on smaller areas, and some products are formulated as no compaction sands specifically for this. Sweep the sand in, work it down with a stiff broom, tap the pavers to settle it, then top up and repeat until the joints are full to within about an eighth of an inch of the surface. Voids left in the joint are what cause cracking later.

Most manufacturers require a minimum of about 1 inch, and many recommend 1.5 inches. Shallow joints are the single most common cause of premature cracking and washout. If you are refilling old joints, remove the failed material down to the required depth first.

No. The new sand will not bond to loose material underneath, so the joint sits on a soft layer and cracks or sinks. Remove the old joint material to the depth the manufacturer specifies, make sure the joints are clean and completely dry, then fill full depth with fresh product.

No. A thin topper will not bond to hardened sand beneath it and typically flakes out within a season. Remove the failed joints properly and reinstall at full depth.

Standard formulas, yes. Water activates the binder and the sand must be watered exactly as the bag instructs. Use a shower style nozzle, water in short stages so the joints absorb rather than flood, and stop before sand starts lifting out of the joints. Air cure and resin products are the exception and set without this step.

Joints normally feel firm within a few hours. Most brands ask for 24 hours before foot traffic and 24 to 48 hours before vehicles. Full cure strength develops over several days.

Rain before the joints have cured can wash binder out, leave weak joints and splash sand onto the paver faces where it stains. Most brands need at least 24 hours of dry weather after activation. If an unexpected shower is coming, tent the area with plastic propped so it does not touch the joints.

Install when both the pavers and the air are above freezing and rising, ideally 50 F or warmer, with dry conditions before and after. Cold, damp or heavy dew conditions slow curing badly and can leave permanently weak joints.

Manufacturers used to say 90 days. The current guidance from most is about 30 days, which lets the joints fully cure and gives any efflorescence time to work its way out. Sealing too early can trap that haze permanently.

The usual causes are overwatering, which flushes the binder out, underwatering, which never activates it, cool or humid weather during cure, sand that got damp before it went in, or loose old material left underneath. Give it several warm dry days before judging. If it is still soft after a week the material generally has to come out and be reinstalled.

Haze is almost always sand left sitting on the paver faces when the water hit it. The binder cured on the surface instead of in the joint. Prevention is simple: sweep the joints, then blow the surface completely clean with a leaf blower before you water, and work in small sections. Existing haze usually needs a dedicated haze remover.

Nearly always joints that were too shallow, water applied wrongly during activation, poor drainage under the pavers, or rain before cure. Fix the underlying cause before refilling, because otherwise the same failure repeats.

It dramatically reduces both. A hardened joint leaves ants little room to tunnel and gives seeds nowhere to root. Seeds that blow onto the surface can still sprout on top of the joint, so occasional maintenance is normal. It is not a permanent guarantee, but it is far better than plain sand.

Soak the joints with hot water to soften the binder, then work the material out with a joint scraper or careful pressure washing. Light surface haze often lifts with hot water and a stiff brush. Heavy cured residue usually needs a dedicated remover.

Yes, once fully cured, but use a wide fan tip at moderate pressure and spray across the surface at an angle rather than straight down into the joints. Direct high pressure can blow out even well cured joints. If a section does come loose, sweep in fresh sand and water it in.

Roughly 75 to 100 sq ft with narrow quarter inch joints, 40 to 60 sq ft with half inch joints, and 20 to 35 sq ft once joints reach three quarters to one inch, assuming about an inch of joint depth. Coverage varies by brand, and small pavers use far more sand than large slabs at the same joint width. Run your exact numbers through our polymeric sand calculator.

Most projects land between 0.3 and 1 lb per square foot. Tight joints on large format slabs sit at the low end, narrow pavers with half inch joints at the high end.

A properly installed joint at full depth commonly lasts 8 to 12 years or more. Poorly installed joints, shallow joints or areas with bad drainage can fail in as little as 3 to 5 years. Lifespan depends far more on installation quality, joint depth and drainage than on brand.

If it was installed correctly, not for the better part of a decade. Expect occasional touch ups where joints meet driveways or downspouts, and expect high traffic vehicular areas to need attention sooner than a patio.

It costs more than plain sand, it needs a dry weather window, and installation is less forgiving. Sand left on the surface hazes, and a hardened joint takes real effort to remove if something goes wrong. For most patios, walkways and driveways the resistance to weeds, ants and washout outweighs those tradeoffs.

It depends on brand, joint width rating and formulation. Wide joint and specialty products cost more than standard sands. Our calculator includes a price per bag field so you can see total project cost before you order.