However, those materials are both heavy and inflexible and require careful treatment.
Sonotubes® are high quality heavy-duty cardboard structures into which concrete is poured to create a smooth-sided column. The tubes have to be able to withstand the pressure of concrete and have a smooth interior to ensure a flawless column wall finish. They are made with spiral wound fiber layers and adhesive bonding, and are extremely strong in cylinder form.
Concrete columns are used in a wide variety of applications, and Sonotube® provides a cost-effective and efficient method of producing a variety of sizes of columns in terms of diameter and length. Short, wide columns are often used as bases for parking lot lamps, streetlights, street signals and deck posts. Tall columns are used for external decoration or roof support around buildings, foundational support in basements and warehouses, and many others.
Other uses have been found for Sonotubes® because of their incredible strength-to-weight ratio and cost-efficiency. Sound technicians and sound hobbyists are using Sonotubes® cut vertically in half to improve the acoustics in auditoriums and sanctuaries. They have also been used to construct sound cabinets as the cardboard walls don’t absorb the sound waves and so are an ideal material choice.
The versatility of Sonotube® is one of its many advantages. When fiberglass or steel column supports are used, the number of columns poured is limited to the equipment on hand. Sonotubes® however are disposable and do not need to be reused, they also do not need added exterior support as fiberglass and steel tubes do. Therefore, the overall construction time is drastically reduced as multiple tubes are able to be poured simultaneously. They are also recyclable.
Once the concrete column has set in the paper tube cavity, the outer cardboard layer can be removed and disposed of. They are typically made from biodegradable paper and so depending on the intended use of the column, can be left on or removed whole or in pieces. The tubes are manufactured between 8 to 56 inches in diameter and up to 18 feet long, Sonotubes® offer versatile solutions for almost any concrete project. The pouring of the concrete is fairly straightforward, although for the longer columns, extra machinery may be required to ensure proper placement of the concrete.