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How Much Concrete for an 8-Inch Sonotube?

An 8-inch diameter Sonotube is commonly used for small deck posts, light structural supports, and mailbox installations. At 4 feet tall, this pier extends below frost lines in many regions. Sonotubes are cardboard forms that create round concrete piers, popular for their ease of use.

Results

Total Volume0.06cubic yards
Total Volume1.54cubic feet
80 lb Bags3bags
60 lb Bags4bags
40 lb Bags6bags
Net Volume (before waste)0.05cu yd
Waste Allowance10%

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