Condensation regulating fabric
Constop Felt - Norway

Economical way to prevent condensation problems

This product is a very economical way to prevent condensation problems. Estimates say 25% cheaper than traditional solutions! Can be used for agricultural, industrial and private building sectors and is offered on all roof profiles with the exception of Sinus 18.

In periods of high humidity, condensation will form on the underside of the roof panel leading to drips onto the items below. The condensation on steel profiles is most apparent in spring and autumn, with the greatest differences in day and night temperature. Constop Filt absorbs up to 1000g water/sq m, giving off moisture when the temperature is above the dew point.

Constop felt
Product specification

EN-Construction-Product-Constop Filt-default

Constop Filt
Specification details

EN-Construction-Product-Constop Filt | Typical properties

Typical properties
Constop Night


1. When the temperature outside drops, the roof becomes cool.
2. The hot air inside condenses when it meets the cooled roofing sheet.
3. Constop Felt absorbs the condensation and stores moisture until the next day.







Constop Day


1. When the outdoor temperature rises again, Constop Felt emits the moisture.
2. The moisture is removed by venting.











1. The building is ventilated, for example, by using ventilation hoods.
2. Install Constop Felt coating approx. 50 mm from the eaves to avoid absorbing rain and melt water.
3. When mounting, the joints must be kept free of Constop Felt coated.









Parameter Standard Unit Delta Value
Weight EN 29073-1 g/m2 ( + / – ) 10% 95
Thickness EN 29073-2 mm   0,8-1,1
Water absorption Internal classification FD 15

NF P 15-203-1

0 gr 2)
45 gr 2)
90 gr 2)
Reaction to fire 1) EN 1350     A2-s1, d0
Adhesion 1) Internal classification FD 15 N/25mm   min. 10
Adhesion after aging 1) Internal classification FD 15 N/25mm   Improved
Sound absorption EN ISO 20354 at 125Hz
Thermal conductivity DIN 52612 W/mK   0,038 3)
Bacterial resistance DIN EN 14119:2003-12 Index 0 – no visible growth under the microscope   x50
Colour       Grå

1) Area of sheet metal
2) Tilt angle
3) Wipe test