Paver joints
- Ratio
- Per the bag’s coverage
- Water
- Mist twice, 10–20 min apart
- Mixing
- None
- Working time
- Same dry day
- Cure
- 24 h no traffic
Pavers and joints dry; fill full, sweep the surface completely clean.
Mixing guides
Polymeric joint sand: activation, rain and cure
Polymeric sand is not a mix: it is bagged joint sand with a binder that activates with water. Most failures are too much water, joints too shallow, or rain too soon.
The bag or tube wins
Product formulations change. If the manufacturer’s printed ratio, temperature or cure differs from this page, follow the manufacturer — and tell us so we can update the guide.
At a glance
By job
Choose the product
- Use polymeric sand only for joints the bag names — typically 1/8–1 in wide and at least 1 in deep.
- For wider gaps, use a chunky joint sand or stone; polymeric sand will wash out or crack.
- Do not use ordinary play sand where the bag says polymeric.
Mix it
- Work on a dry day with dry pavers and dry joints.
- Sweep the sand diagonally into the joints until they are full; blow or brush the surface completely clean.
- Mist with a fine spray until the sand darkens — do not puddle. Wait 10–20 minutes and mist again.
- Top up any joint that settles low before the 24-hour cure.
Weather window
Temperature
50–90°F (10–32°C)
Rain
No rain for 24 hours. Cover the field if rain threatens.
Watch for
- Avoid windy days; the sand blows out of the joints.
- Do not activate on frozen joints or when the temperature will drop below 50°F that night.
Cure
- Keep traffic off for 24 hours.
- Re-sand low joints after the first winter and after heavy washing.
When it goes wrong
Sand washes out
Likely cause: Too much water, or rain before the binder set.
Fix: Mist lightly, cover from rain, and top up after the cure.
A crust forms on top
Likely cause: Over-watering left a film on the pavers.
Fix: Break the crust, clean the surface and re-sand the joints.
Weeds or puddles at the joints
Likely cause: Joints too shallow, or the base drains poorly.
Fix: Top up the joint depth and fix the base drainage — sand cannot compensate.
Safety
- Wear eye protection and a dust mask when sweeping dry sand.
- Keep the sand away from storm drains and planting beds.
Sources
- Quikrete — polymeric sand instructions — Joint width, temperature and rain window vary by product; the bag wins.
- ICPI — Interlocking Concrete Pavement Institute — Background on joint sand and pavement performance.