Technical Info

Fully-pre-fabricated blast resistant panels

Our G21 blast resistant panels are passive fire/blast protection wall panels, designed, manufactured and tested by InterDam BV. The blast rated sandwich panels are fully prefabricated and pre-coated, made from realigned layers of fibers sandwiched between two metal sheets and available for blast ratings up to 0.8 bar blast with special designed panel supports.

Exceptional protection by sandwichpanels

Special pressed and glued mineral wool serves as the core material for the panel, which is standardly-provided with coil-coated HPS 200 mu mild steel skins (0.7 mm thickness). Our clients can also choose stainless steel 316 skins (2B finish or coil-coated 25 mu PVDF) as an option. The result is a heavy duty fire resistant panel using the minimum amount of materials to provide exceptional blast protection.

Suitable for a variety of projects

G21 blast panels can be used as internal or external fire/blast walls. The prefabricated fire panels are suitable for projects with blast resistance requirements, including:
• Offshore wind substations
• Petro chemical plants
• Oil & Gas platforms/plants

Fully tested and certified

Our prefabricated panels have been extensively tested for both fire and blast resistance. Blast resistant panels have been tested in various construction ways, conditions and blast overpressure varieties at the RAF Spadeadam testing facilities in the United Kingdom.


Currently there are no regulations covering a fire outbreak in a post blast situation so manufacturers tend to supply products that can either withstand a blast or are resistant to fire but not both consecutively.

We have actually tested our walls, doors and windows to withstand not only the impact of a blast, but also an immediate fire outbreak. We have tested our G21 Blast Panel’s fire resistance following a 0.25 bar overpressure blast test. The panel achieved a fire post blast rating of H120 and EI240 (H240) following exposure to a hydrocarbon fire for 240 minutes without showing signs of deterioration in performance. Click here to receive the free span tables of A60, EI180, H120 and EI240.


G21 blast resistant panels are delivered as ready-to-install panels, supplied with stainless steel self-tapping screws (and flashings to finish the walls upon request) to the special tested designed reinforcements. Installation can easily be performed using standard tooling equipment – no hotwork is are required.

Cost-effective solution

This sandwich wall system G21 Blast Panel is a new cost-effective solution comparing to the different previous types of wall systems. This wall system is compared to other wall types in the below table based on total costs.

Are you interested in more information about the several wall types and how your project can benefit of using the fire and blast sandwich panels, contact us here.

Other available options

• Design and engineering support for your project from our experienced in-house engineering team
• Blast relief function of the panels
• Fire resistance (A60, H120 or jet fire ratings)
• Integration of fire/blast doors or windows
• Packing and worldwide transport
• Installation support