SEK PolySweep Polymeric Sand: Joints, Coverage and Install

SEK PolySweep polymeric sand is a haze-free jointing sand from SEK-Surebond for paver, stone and porcelain joints up to 3/4 inch wide. It goes in dry, gets compacted into the joints, and hardens into a semi-solid joint once you activate it with water. This guide covers what it is, where it fits, how much you need, how SEK says to install it, and which colors it comes in.

Every figure below comes from SEK's PolySweep technical data sheet or brochure, and we name the source as we go. Your bag and the current data sheet are the final word, so read both before you start.

What SEK PolySweep polymeric sand is

According to SEK's data sheet, PolySweep is a blend of native sands that conform to the ASTM C-144 standard plus polymer binders. ASTM C-144 describes fractured, angular sand in a range of particle sizes, which SEK says creates the structure that interlocks the joint once the polymers are activated with water and cured. The cured joint is designed to flex with heat, cold and freeze/thaw cycles while helping to prevent sand erosion from rain and runoff, lessen weed growth and deter insects.

SEK formulates PolySweep with what it calls Clear Set Technology, which it states will not discolor the surface or leave a haze. SEK also states that the product's respirable crystalline silica level is below reportable limits under normal use, based on certified lab testing. You should still wear eye protection and a respirator during installation, as the data sheet requires.

Where you can use it

• Projects: new or existing residential and commercial driveways, walkways, patios, pool decks and concrete overlays.
• Surfaces: concrete, clay and wet cast pavers, natural stone and porcelain tile.
• Not for: vertical applications, or as a substitute for mortar.

SEK's catalog also describes PolySweep as a non-permeable joint fill option when it is installed over an open-graded (permeable) base. If you need the joints themselves to drain, look at our resin and permeable jointing sands instead.

PolySweep joint width and depth

Joint size decides which PolySweep you need. SEK sells two versions, and both use the same data sheet.

If your joints run wider than 3/4 inch anywhere, SEK PolySweep X-Treme Wide Joint is the SEK option built for that range. For typical paver joints up to 3/4 inch, SEK PolySweep in the 50 lb bag is the one to look at.

PolySweep coverage per 50 lb bag

These are SEK's estimated coverage figures for standard PolySweep, taken from the PolySweep technical data sheet. They are the same figures our calculator uses.

SEK notes that coverage varies with the shape, size and depth of the pavers. Deep joints, tumbled edges and irregular stone all use more sand per square foot. To turn your square footage and joint width into a bag count, use our polymeric sand calculator and round up.

Before you install: base and conditions

Base requirements

SEK says PolySweep works best over a base built to ICPI recommended practice (ICPI Tech Spec 2 and Tech Spec 10). For concrete pavers, slabs and natural stone that means a 3/4 inch modified stone base and a concrete sand setting bed conforming to ASTM C33. On open-graded bases, the bedding stone should be small enough to choke the base layer, and SEK notes some PolySweep may migrate into the bedding layer.

For concrete overlays (pavers set over an existing slab), the data sheet calls for at least a 1% slope on the concrete and a 1 inch layer of bedding sand, and water must be able to escape at the perimeter. If you are setting directly on concrete, read the overlay section of the data sheet for SEK's drainage details before you start.

Weather and temperature

• Pavement joints and surface must be completely dry. SEK warns that applying to a wet or damp surface makes the sand stick to the pavers.
• No rain forecast for at least 12 hours after installation. If rain is possible, cover with a tarp and remove it as soon as the threat passes (a tarp extends curing time).
• Average ambient air temperature above 35 degrees for at least 48 hours after installation.
• Do not install in rain, and turn off irrigation systems.

How to install SEK PolySweep polymeric sand

This is a summary of SEK's five installation steps. Follow the instructions on your bag and the full data sheet on the day.

1. Prepare the surface. Sweep or blow off the surface, do spot and overall cleaning, and let it dry completely.
2. Spread and sweep. Distribute PolySweep evenly and sweep it into the joints until full. Avoid pushing sand across the surface for long distances.
3. Compact. Run a vibratory compactor over pavers. For porcelain or natural stone, use a vibratory roller or a rubber hammer and a piece of wood, and skip compaction if the porcelain manufacturer advises against it. Top up and repeat. Finished sand should sit 1/8 inch below the surface or at the bottom of the chamfer.
4. Clean the surface. Sweep off excess, then use a leaf blower held close to parallel to the surface to clear residual dust without pulling sand from the joints.
5. Water. With a hose on the shower setting, gently mist no more than 500 sq ft at a time. Let the water soak in for about 5 minutes, then repeat 3 and up to 4 times, increasing the volume each time. The full joint depth must be saturated. Use the last watering to rinse residue off the surface, then blow off water left in the paver texture.

Good brooms and a blower make steps 2 and 4 easier. Our sweeping and cleanup tools are built for this job.

Curing, cleanup and storage

SEK defines initial set up as the point where the sand has enough cohesion that heavy rain or strong wind will not move it out of the joint. PolySweep is fully cured when the sand has dried and the joint is hard. SEK says curing depends on temperature and humidity and could take up to 24 hours or longer, and cool, damp, overcast weather can lengthen it.

If sand cures on the paver surface, SEK recommends scraping with a plastic putty knife, then boiling water and a stiff bristle brush or a hot water pressure washer. For stubborn residue SEK points to SEK SureStrip. Clean, dry leftover sand can be kept for a later project in its original packaging.

Per the data sheet, PolySweep has a 24 month shelf life. Store it in a cool, dry place below 90 degrees F, and protect the bag from punctures, constant moisture and long-term UV exposure.

PolySweep colors

SEK lists PolySweep in Pearl, Tan, Gray, Fieldstone, Platinum and Black. Pearl is not made in X-Treme Wide Joint, and SEK notes color availability can vary by region. SEK also says the finished color can vary with the natural aggregates and moisture content, so a swatch on a screen is only a starting point.

The simplest check is a physical sample next to your pavers. Our PolySweep color sample kit includes the colors we stock in 2 oz packs.

Who SEK PolySweep suits

PolySweep is a good fit if your project matches its data sheet:

• Joints up to 3/4 inch on concrete, clay or wet cast pavers, natural stone or porcelain.
• A conventional base, or an open-graded base where you are fine with a non-permeable joint.
• A forecast that gives you a dry surface, 12 rain-free hours after install and temperatures above 35 degrees for 48 hours.
• Installers who can compact and water in stages across the whole joint depth.

If your joints are wider, your stone is irregular, or you cannot count on a dry weather window, compare other options in our polymeric sand collection, where each product lists its own joint range and conditions.

Frequently asked questions

What joint width is SEK PolySweep rated for?

Standard PolySweep is rated for joints up to 3/4 inch. PolySweep X-Treme Wide Joint is rated up to 4 inches. Both figures come from SEK's data sheet.

How deep do PolySweep joints need to be?

SEK's minimum depth is 1.5 inches for PolySweep and 1.25 inches for X-Treme Wide Joint. After compaction, the sand should sit 1/8 inch below the surface or at the bottom of the chamfer.

How many square feet does a bag of PolySweep cover?

SEK estimates 50 to 75 sq ft per 50 lb bag for joints up to 1/4 inch, 25 to 50 sq ft for 1/4 to 1/2 inch, and 15 to 25 sq ft for 1/2 to 3/4 inch. Actual coverage depends on paver shape, size and depth.

How long does PolySweep need to stay dry?

The data sheet calls for no rain forecast for at least 12 hours after installation. SEK says full curing could take up to 24 hours or longer, depending on temperature and humidity.

Can PolySweep be used on porcelain tile?

Yes. SEK lists porcelain tile as a suitable surface. Consolidate with a vibratory roller or a rubber hammer and wood block, and do not compact if the porcelain manufacturer advises against it.