Precon Products, A leading national independent supplier of construction products


Monotub D.D. Cardboard Column Formers

Exclusively distributed in the UK by Precon Products

Monotub D.D. cardboard column formers

The use of one way cardboard column formers in all kinds of construction work is considered to be very normal all over the European continent. Circular columns, supportive or only decorative, are adding extra dimensions to the interior or exterior of a building. However, cost reduction is the main reason for constructors to use Monotub DD as formwork for circular columns.

Introducing Monotub DD cardboard column formers

  • Monotub DD improves rapid construction because erecting, pouring the concrete, and removing the formwork can be done very quickly.
  • Costs for concrete can be reduced, because it can be delivered for all columns at once.
  • Monotub DD is extremely light, and can simply be erected by one man, without the use of cranes.
  • In most cases, traditional formwork that could be available, has to be adjusted to the sizes required, while Monotub DD usually is delivered to your specification.

Monotub DD is produced out of recycled waterproof carton. The product is 100% water resistant and can be used in all possible weather conditions. Every storage on site can be done without the risk of damaging the quality of the formwork because of humidity or rain.

Another advantage of Monotub DD is the fact that the formwork can be removed at the moment suitable for you, which enables you to increase efficiency on manpower. Besides, the formwork can be used as column protection, after the concrete has cured.

Monotub DD for circular columns is available in 3 types:

  1. Spiral.
  2. Smooth, for a perfectly flat surface.
  3. Speed, an equal smooth column form, which can be removed very quickly by pulling down the steel line that is in the tube and functions as a ‘zipper’.

Standard sizes


  • 200 x 200mm
  • 250 x 250mm
  • 300 x 300mm
  • 350 x 350mm
  • 400 x 400mm
  • 450 x 450mm
  • 500 x 500mm


  • 200 x 300mm
  • 250 x 300mm
  • 250 x 350mm
  • 250 x 400mm
  • 300 x 350mm
  • 300 x 400mm
  • 300 x 450mm
  • 300 x 500mm
  • 300 x 600mm
  • 400 x 500mm
  • 400 x 600mm

An important detail is that Monotub DD usually being produced on clients specifications per project.

You will never have difficulties when ‘overlengths’ have to be adjusted.

Of course, for emergency situations we have almost every diameter in stock in ‘Speed’ type.This stock consists of lengths of 3 and 4 meters.

Monotub DD illustration

Monotub D.D. on site

Technical specification

Diameter in mm Concrete in dm3 per mtr column Surface quality class of concrete* Wall thickness in mm (ca.) Weight of tube in kgs per mtr
15218,1I A31,3
20232,0I A31,7
25049,1I A32,1
30070,6I A32,5
35096,2I A43,6
400125,6I A44,1
450159,0I A44,6
500196,3I A45,1
550237,6I A56,3
600282,7I A56,9
650333,8I A57,5
700384,8I A58,0
800515,3I A59,3
900650,4I A510,5
1000785,4I A611,5
12001131,0I C613,7

* according to NEN 6722 (normmative regarding smoothness of concrete surface) except for the vertical joint on inside.


Monotub DD offers you the advantage of waterproofness: it is not necessary to pour the concrete immediately after erecting the tubes.You can determine when this should be done, without the need for covering the formwork against rain etc.

Pouring the column

Pouring the concrete is easy with Monotub DD; because of its strength it is possible to pour the column in one move, but you will get the best result when the condensed after every 50 cm. (beware of damaging the inside of the tube) With longer columns it is advisable to prevent the concrete from falling too deep, and the formwork.

Removing the column form

Monotub DD can be removed very easily with e.g. a knife, however the ‘Speed’-type is provided with a ‘zipper’ of 0,5mm steel. With this line you can cut the column former open in one move.The smooth film that remains on the column, can easily be removed by hand. After removing the former, you can put it back into place, to protect the column.

Because of the waterproof compositions of the former, it is not necessary to remove it immediately; this can be done at any suitable moment.

Monotub D.D. cardboard column former close up