SAKRETE Builders’ Tubes

Produce round concrete supports! Use SAKRETE Builders’ Tubes, pre-fabricated, fiber tubes for below-ground placement. Go with SAKRETE, The Pro’s Choice since 1936.

Product Codes:
6″ x 12′: 13602006, 23601206
8″ x 12′: 13602008, 23601208
10″ x 12′: 13602010, 23601210
12″ x 12′: 13602012, 23601212
6″ x 8′: 13601006, 23601006
8″ x 8′: 13601008, 23601008
10″ x 8′: 13601010, 23601010
12″ x 8′: 13601012, 23601012

• High quality, pre-fabricated, fiber tubes for below-ground placement
• Ideal for use as a form to produce round concrete supports
• Can be used up to 3 feet (91 cm) above ground; bracing required above 2 feet (61 cm)
• Available in 8 foot lengths (6 inch, 8 inch, 10 inch, 12 inch diameters)
• Available in 12 foot lengths (6 inch, 8 inch, 10 inch, 12 inch, 16 inch, 18 inch, 24 inch diameters)
• Packaged in sets of 3 nested tubes



• Professional finish
• Inexpensive time saver
• Available in various sizes


Ideal for constructing concrete columns for footings, piers, deck supports, fences, basket ball posts, backyard play areas, mail boxes and lamp posts. Also used for storage, shipping and for display purposes (covered with carpet or paint).


Surface Preparation: Dig hole to the required depth. Extend below frost line.

Placing: Place the tube in the hole and back fill with dirt around the outside of the tube to secure. NOTE: Tubes are marked “UP” with an arrow and should be placed that way. Failure to do so may cause the joints to leak and tube could collapse even if it is in the ground. Continue placing and secure all the tubes.

Bracing: SAKRETE Builders’ Tubes are designed for below-grade use, but may be poured to 1 m (3 ft) above the ground line. If the tube extends more than 61 cm (2 ft) above the ground-line, provide additional support with a collar or wooden frame and side braces. Filling: Be sure tube is dry and level vertically before filling with concrete and remains stationary until the concrete sets. NOTE: Do not use a mechanical vibrator when placing concrete in the SAKRETE Builders’ Tubes.

Stripping: SAKRETE Builders’ Tubes are designed to be left in place. They are not designed to be stripped. Should you desire to strip the forms, be sure to use a reliable release agent before pouring the concrete. Remove the forms as soon as possible after a 24 hour curing period. Carefully cut the form vertically, using a knife or power saw and remove form. NOTE: No warranty is extended on the finished concrete surface.


SAKRETE Builders’ Tubes may be painted.



# of Bags

Tube Measurement With Post (4″ x 4″) Without Post 
6″ Diameter Tube x 4 ft  1.0 Bag 1.5 Bags
8″ Diameter Tube x 4 ft 2.0 Bags 3.0 Bags
10″ Diameter Tube x 4 ft 4.0 Bags 4.5 Bags
12″ Diameter Tube x 4 ft 5.5 Bags 6.5 Bags


Material should be stored in a dry covered area protected from the elements. For temporary storage, place tubes vertical on an elevated platform at least 4” (10 cm) off the ground and under cover, allowing circulation of air through the tubes.


This product is designed to meet the performance specifications outlined in this product data sheet. If the product is used in conditions for which it was not intended, or applied in a manner contrary to the written recommendations contained in the product data sheet, the product may not reach such performance specifications. The foregoing is in lieu of any other warranties, representations or conditions, expressed or implied, including, but not limited to, implied warranties or conditions of merchantable quality or fitness for particular purposes, and those arising by statute or otherwise in law or from a course of dealing or usage of trade.

Product Calculator

How Much Do I Need?

Calculate how much of a product you need, then add it to your Shopping List.
Jump To Calculator Icon

Jump To Calculator

How-To Video

More Information

PLEASE NOTE: This product was previously known as KING Builder's Tubes.

SAKRETE Builders' Tubes are nested in sets of three. For example, a 6” set would consist of tubes of 5.5”, 6” and 6.5” diametres.

Bags of concrete are required for installation of SAKRETE Builders' Tubes. To determine how many bags of 30 KG concrete are required for various tube diametres and lengths, reference the Yield section of the Technical Data Sheet.