How Much Polymeric Sand Do I Need? Bags by Joint Width

It depends far more on joint width and paver size than on area. A 12 × 12 ft patio of 4 × 8 in pavers with ⅛ in joints takes about 4 bags of 50 lb polymeric sand. Wider joints and smaller pavers take much more.

Count pavers by their size plus one joint; work out sand and base as area × depth, plus extra for compaction.

Bags per 100 sq ft

50 lb bags per 100 sq ft, joints filled to full depth, with 10% extra
Pavers	⅛ in joints	¼ in joints	⅜ in joints
8 × 4 in, 2.375 in thick	3	5	7
6 × 6 in, 2.375 in thick	2	4	6
12 × 12 in, 2.375 in thick	2	2	3
24 × 12 in, 2 in thick	1	2	2

Metric: 22.7 kg bags per 10 m², with 10% extra
Pavers	3 mm joints	6 mm joints	10 mm joints
200 × 100 mm, 60 mm thick	3	5	8
200 × 200 mm, 60 mm thick	2	4	5
400 × 400 mm, 40 mm thick	1	2	2
600 × 300 mm, 40 mm thick	1	2	2

These fill every joint to the full paver depth, so they err high: bedding sand usually rises into the bottom of the joints. Sika's data sheet gives 60–90 sq ft (5.6–8.4 m²) per 50 lb bag for narrow joints, and Alliance Gator says pavers with spacer bars use 10–15% less.

How it's worked out

Each paver and its share of joint make a rectangle: (8 + ⅛) × (4 + ⅛) in.
The joint is the part the paver doesn't cover: 4.5% of the surface.
Volume: 144 sq ft × 4.5% × 2⅜ in deep = 1.29 cu ft.
Weight at 106 lb per cu ft (Sika's figure), plus 10%: about 159 lb, so 4 bags of 50 lb.

Common mistakes

Buying by area alone. Coverage on the bag assumes a joint size; check it matches yours.
Wet pavers. Sand sticks to damp surfaces and can haze. Work on a dry day.
Not compacting. Run a plate compactor and top up until the sand stops settling.

Bags per 100 sq ft

How it's worked out

Common mistakes

Sources

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